curl 7.72.0 (i386-pc-win32) libcurl/7.72.0 OpenSSL/1.1.1g (Schannel) zlib/1.2.11 brotli/1.0.7 zstd/1.4.5 WinIDN libssh2/1.9.0 nghttp2/1.41.0
Release-Date: 2020-08-19
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps mqtt pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp 
Features: AsynchDNS HTTP2 HTTPS-proxy IDN IPv6 Kerberos Largefile MultiSSL NTLM SPNEGO SSL SSPI TLS-SRP Unicode UnixSockets brotli libz zstd
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NAME
       curl - transfer a URL

SYNOPSIS
       curl [options / URLs]

DESCRIPTION
       curl  is  a tool to transfer data from or to a server, using one of the
       supported protocols (DICT, FILE, FTP, FTPS, GOPHER, HTTP, HTTPS,  IMAP,
       IMAPS,  LDAP,  LDAPS,  MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP,
       SMB, SMBS, SMTP, SMTPS, TELNET and TFTP). The command  is  designed  to
       work without user interaction.

       curl offers a busload of useful tricks like proxy support, user authen-
       tication, FTP upload, HTTP post, SSL connections, cookies, file  trans-
       fer  resume,  Metalink,  and more. As you will see below, the number of
       features will make your head spin!

       curl is powered by  libcurl  for  all  transfer-related  features.  See
       libcurl(3) for details.

URL
       The  URL  syntax is protocol-dependent. You'll find a detailed descrip-
       tion in RFC 3986.

       You can specify multiple URLs or parts of URLs  by  writing  part  sets
       within braces and quoting the URL as in:

         "http://site.{one,two,three}.com"

       or you can get sequences of alphanumeric series by using [] as in:

         "ftp://ftp.example.com/file[1-100].txt"

         "ftp://ftp.example.com/file[001-100].txt"    (with leading zeros)

         "ftp://ftp.example.com/file[a-z].txt"

       Nested  sequences  are not supported, but you can use several ones next
       to each other:

         "http://example.com/archive[1996-1999]/vol[1-4]/part{a,b,c}.html"

       You can specify any amount of URLs on the command line.  They  will  be
       fetched  in a sequential manner in the specified order. You can specify
       command line options and URLs mixed and in any  order  on  the  command
       line.

       You  can  specify a step counter for the ranges to get every Nth number
       or letter:

         "http://example.com/file[1-100:10].txt"

         "http://example.com/file[a-z:2].txt"

       When using [] or {} sequences when invoked from a command line  prompt,
       you probably have to put the full URL within double quotes to avoid the
       shell from interfering with it. This also  goes  for  other  characters
       treated special, like for example '&', '?' and '*'.

       Provide  the IPv6 zone index in the URL with an escaped percentage sign
       and the interface name. Like in

         "http://[fe80::3%25eth0]/"

       If you specify URL without protocol:// prefix,  curl  will  attempt  to
       guess  what  protocol  you might want. It will then default to HTTP but
       try other protocols based on often-used host name prefixes.  For  exam-
       ple,  for  host names starting with "ftp." curl will assume you want to
       speak FTP.

       curl will do its best to use what you pass to it as a URL.  It  is  not
       trying  to  validate it as a syntactically correct URL by any means but
       is instead very liberal with what it accepts.

       curl will attempt to re-use connections for multiple file transfers, so
       that  getting many files from the same server will not do multiple con-
       nects / handshakes. This improves speed. Of course this is only done on
       files  specified  on  a  single command line and cannot be used between
       separate curl invokes.

PROTOCOLS
       curl supports numerous protocols, or put in URL  terms:  schemes.  Your
       particular build may not support them all.

       DICT   Lets you lookup words using online dictionaries.

       FILE   Read  or  write  local  files.  curl  does not support accessing
              file:// URL remotely, but when running on Microsft Windows using
              the native UNC approach will work.

       FTP(S) curl  supports  the  File Transfer Protocol with a lot of tweaks
              and levers. With or without using TLS.

       GOPHER Retrieve files.

       HTTP(S)
              curl supports HTTP with numerous options and variations. It  can
              speak HTTP version 0.9, 1.0, 1.1, 2 and 3 depending on build op-
              tions and the correct command line options.

       IMAP(S)
              Using the mail reading protocol, curl can "download" emails  for
              you. With or without using TLS.

       LDAP(S)
              curl can do directory lookups for you, with or without TLS.

       MQTT   curl supports MQTT version 3. Downloading over MQTT equals "sub-
              scribe" to a topic while uploading/posting equals "publish" on a
              topic.  MQTT  support  is experimental and TLS based MQTT is not
              supported (yet).

       POP3(S)
              Downloading from a pop3 server means getting  a  mail.  With  or
              without using TLS.

       RTMP(S)
              The  Realtime  Messaging  Protocol  is  primarily used to server
              streaming media and curl can download it.

       RTSP   curl supports RTSP 1.0 downloads.

       SCP    curl supports SSH version 2 scp transfers.

       SFTP   curl supports SFTP (draft 5) done over SSH version 2.

       SMB(S) curl supports SMB version 1 for upload and download.

       SMTP(S)
              Uploading contents to an SMTP server  means  sending  an  email.
              With or without TLS.

       TELNET Telling curl to fetch a telnet URL starts an interactive session
              where it sends what it reads  on  stdin  and  outputs  what  the
              server sends it.

       TFTP   curl can do TFTP downloads and uploads.

PROGRESS METER
       curl  normally  displays a progress meter during operations, indicating
       the amount of transferred data,  transfer  speeds  and  estimated  time
       left,  etc.  The progress meter displays number of bytes and the speeds
       are in bytes per second. The suffixes (k, M, G, T, P) are  1024  based.
       For example 1k is 1024 bytes. 1M is 1048576 bytes.

       curl  displays  this  data to the terminal by default, so if you invoke
       curl to do an operation and it is about to write data to the  terminal,
       it disables the progress meter as otherwise it would mess up the output
       mixing progress meter and response data.

       If you want a progress meter for HTTP POST or PUT requests, you need to
       redirect  the  response output to a file, using shell redirect (>), -o,
       --output or similar.

       It is not the same case for FTP upload as that operation does not  spit
       out any response data to the terminal.

       If  you  prefer  a  progress  "bar"  instead  of the regular meter, -#,
       --progress-bar is your friend. You can also disable the progress  meter
       completely with the -s, --silent option.

OPTIONS
       Options  start  with  one or two dashes. Many of the options require an
       additional value next to them.

       The short "single-dash" form of the options, -d  for  example,  may  be
       used with or without a space between it and its value, although a space
       is a recommended separator. The long "double-dash" form, -d, --data for
       example, requires a space between it and its value.

       Short version options that don't need any additional values can be used
       immediately next to each other, like for example you  can  specify  all
       the options -O, -L and -v at once as -OLv.

       In general, all boolean options are enabled with --option and yet again
       disabled with --no-option. That is, you use the exact same option  name
       but prefix it with "no-". However, in this list we mostly only list and
       show the --option version of them. (This concept with --no options  was
       added  in  7.19.0.  Previously  most options were toggled on/off on re-
       peated use of the same command line option.)

       --abstract-unix-socket <path>
              (HTTP) Connect through an abstract Unix domain  socket,  instead
              of  using  the  network.  Note: netstat shows the path of an ab-
              stract socket prefixed with '@',  however  the  <path>  argument
              should not have this leading character.

              Added in 7.53.0.

       --alt-svc <file name>
              (HTTPS) WARNING: this option is experimental. Do not use in pro-
              duction.

              This option enables the alt-svc parser in curl. If the file name
              points to an existing alt-svc cache file, that will be used. Af-
              ter a completed transfer, the cache will be saved  to  the  file
              name again if it has been modified.

              Specify a "" file name (zero length) to avoid loading/saving and
              make curl just handle the cache in memory.

              If this option is used several times, curl  will  load  contents
              from all the files but the last one will be used for saving.

              Added in 7.64.1.

       --anyauth
              (HTTP) Tells curl to figure out authentication method by itself,
              and use the most secure one the remote site claims  to  support.
              This is done by first doing a request and checking the response-
              headers, thus possibly inducing  an  extra  network  round-trip.
              This  is  used  instead  of  setting  a  specific authentication
              method, which you can do with  --basic,  --digest,  --ntlm,  and
              --negotiate.

              Using --anyauth is not recommended if you do uploads from stdin,
              since it may require data to be sent twice and then  the  client
              must  be able to rewind. If the need should arise when uploading
              from stdin, the upload operation will fail.

              Used together with -u, --user.

              See also --proxy-anyauth and --basic and --digest.

       -a, --append
              (FTP SFTP) When used in an upload, this makes curl append to the
              target  file  instead  of  overwriting  it.  If  the remote file
              doesn't exist, it will be created.  Note that this flag  is  ig-
              nored by some SFTP servers (including OpenSSH).

       --basic
              (HTTP)  Tells curl to use HTTP Basic authentication with the re-
              mote host. This is the default and this option is usually point-
              less, unless you use it to override a previously set option that
              sets a different authentication method (such  as  --ntlm,  --di-
              gest, or --negotiate).

              Used together with -u, --user.

              See also --proxy-basic.

       --cacert <file>
              (TLS) Tells curl to use the specified certificate file to verify
              the peer. The file may contain  multiple  CA  certificates.  The
              certificate(s)  must be in PEM format. Normally curl is built to
              use a default file for this, so this option is typically used to
              alter that default file.

              curl  recognizes the environment variable named 'CURL_CA_BUNDLE'
              if it is set, and uses the given path as a path  to  a  CA  cert
              bundle. This option overrides that variable.

              The  windows  version  of  curl will automatically look for a CA
              certs file named 'curl-ca-bundle.crt', either in the same direc-
              tory as curl.exe, or in the Current Working Directory, or in any
              folder along your PATH.

              If curl is built against  the  NSS  SSL  library,  the  NSS  PEM
              PKCS#11 module (libnsspem.so) needs to be available for this op-
              tion to work properly.

              (iOS and macOS only) If curl is built against Secure  Transport,
              then  this  option  is supported for backward compatibility with
              other SSL engines, but it should not be set. If  the  option  is
              not  set,  then curl will use the certificates in the system and
              user Keychain to verify the peer, which is the preferred  method
              of verifying the peer's certificate chain.

              (Schannel only) This option is supported for Schannel in Windows
              7 or later with libcurl 7.60 or later. This option is  supported
              for backward compatibility with other SSL engines; instead it is
              recommended to use Windows' store of root certificates (the  de-
              fault for Schannel).

              If this option is used several times, the last one will be used.

       --capath <dir>
              (TLS)  Tells  curl to use the specified certificate directory to
              verify the peer. Multiple paths can be  provided  by  separating
              them with ":" (e.g.  "path1:path2:path3"). The certificates must
              be in PEM format, and if curl is built against OpenSSL, the  di-
              rectory must have been processed using the c_rehash utility sup-
              plied with OpenSSL. Using  --capath  can  allow  OpenSSL-powered
              curl  to  make  SSL-connections much more efficiently than using
              --cacert if the --cacert file contains many CA certificates.

              If this option is set, the default capath value will be ignored,
              and if it is used several times, the last one will be used.

       --cert-status
              (TLS)  Tells curl to verify the status of the server certificate
              by using the Certificate Status Request (aka. OCSP stapling) TLS
              extension.

              If  this option is enabled and the server sends an invalid (e.g.
              expired) response, if the response suggests that the server cer-
              tificate  has  been  revoked, or no response at all is received,
              the verification fails.

              This is currently only implemented in the  OpenSSL,  GnuTLS  and
              NSS backends.

              Added in 7.41.0.

       --cert-type <type>
              (TLS)  Tells  curl  what type the provided client certificate is
              using. PEM, DER, ENG and P12 are recognized types.  If not spec-
              ified, PEM is assumed.

              If this option is used several times, the last one will be used.

              See also -E, --cert and --key and --key-type.

       -E, --cert <certificate[:password]>
              (TLS)  Tells  curl  to use the specified client certificate file
              when getting a file with HTTPS, FTPS or another SSL-based proto-
              col.  The  certificate must be in PKCS#12 format if using Secure
              Transport, or PEM format if using any other engine.  If the  op-
              tional  password  isn't specified, it will be queried for on the
              terminal. Note that this option  assumes  a  "certificate"  file
              that is the private key and the client certificate concatenated!
              See -E, --cert and --key to specify them independently.

              If curl is built against the NSS SSL library  then  this  option
              can  tell curl the nickname of the certificate to use within the
              NSS database defined by the environment variable SSL_DIR (or  by
              default  /etc/pki/nssdb).  If  the  NSS PEM PKCS#11 module (lib-
              nsspem.so) is available then PEM files may  be  loaded.  If  you
              want to use a file from the current directory, please precede it
              with "./" prefix, in order to avoid confusion with  a  nickname.
              If  the nickname contains ":", it needs to be preceded by "\" so
              that it is not recognized as password delimiter.  If  the  nick-
              name  contains "\", it needs to be escaped as "\\" so that it is
              not recognized as an escape character.

              If curl is built against OpenSSL library, and the engine  pkcs11
              is available, then a PKCS#11 URI (RFC 7512) can be used to spec-
              ify a certificate located in a PKCS#11 device. A  string  begin-
              ning  with  "pkcs11:" will be interpreted as a PKCS#11 URI. If a
              PKCS#11 URI is provided, then the --engine option will be set as
              "pkcs11" if none was provided and the --cert-type option will be
              set as "ENG" if none was provided.

              (iOS and macOS only) If curl is built against Secure  Transport,
              then the certificate string can either be the name of a certifi-
              cate/private key in the system or user keychain, or the path  to
              a  PKCS#12-encoded  certificate  and private key. If you want to
              use a file from the current directory, please  precede  it  with
              "./" prefix, in order to avoid confusion with a nickname.

              (Schannel  only) Client certificates must be specified by a path
              expression to a certificate store.  (Loading  PFX  is  not  sup-
              ported; you can import it to a store first). You can use "<store
              location>\<store name>\<thumbprint>" to refer to  a  certificate
              in   the   system  certificates  store,  for  example,  "Curren-
              tUser\MY\934a7ac6f8a5d579285a74fa61e19f23ddfe8d7a".   Thumbprint
              is  usually  a SHA-1 hex string which you can see in certificate
              details. Following store locations are  supported:  CurrentUser,
              LocalMachine,  CurrentService, Services, CurrentUserGroupPolicy,
              LocalMachineGroupPolicy, LocalMachineEnterprise.

              If this option is used several times, the last one will be used.

              See also --cert-type and --key and --key-type.

       --ciphers <list of ciphers>
              (TLS) Specifies which ciphers to use in the connection. The list
              of  ciphers  must  specify  valid ciphers. Read up on SSL cipher
              list details on this URL:

               https://curl.haxx.se/docs/ssl-ciphers.html

              If this option is used several times, the last one will be used.

       --compressed-ssh
              (SCP SFTP) Enables built-in SSH compression.  This is a request,
              not an order; the server may or may not do it.

              Added in 7.56.0.

       --compressed
              (HTTP) Request a compressed response using one of the algorithms
              curl supports, and automatically decompress the content. Headers
              are not modified.

              If  this  option is used and the server sends an unsupported en-
              coding, curl will report an error.

       -K, --config <file>

              Specify a text file to read curl  arguments  from.  The  command
              line  arguments  found  in the text file will be used as if they
              were provided on the command line.

              Options and their parameters must be specified on the same  line
              in the file, separated by whitespace, colon, or the equals sign.
              Long option names can optionally be given  in  the  config  file
              without the initial double dashes and if so, the colon or equals
              characters can be used as separators. If the option is specified
              with  one or two dashes, there can be no colon or equals charac-
              ter between the option and its parameter.

              If the parameter contains whitespace (or starts with  :  or  =),
              the  parameter  must  be  enclosed  within quotes. Within double
              quotes, the following escape sequences are  available:  \\,  \",
              \t, \n, \r and \v. A backslash preceding any other letter is ig-
              nored. If the first column of a config line is a '#'  character,
              the  rest  of  the line will be treated as a comment. Only write
              one option per physical line in the config file.

              Specify the filename to -K, --config as '-' to  make  curl  read
              the file from stdin.

              Note  that  to  be able to specify a URL in the config file, you
              need to specify it using the --url option,  and  not  by  simply
              writing  the  URL  on its own line. So, it could look similar to
              this:

              url = "https://curl.haxx.se/docs/"

              When curl is invoked, it (unless -q, --disable is  used)  checks
              for a default config file and uses it if found. The default con-
              fig file is checked for in the following places in this order:

              1) curl tries to find the "home dir": It first  checks  for  the
              CURL_HOME and then the HOME environment variables. Failing that,
              it uses getpwuid() on Unix-like systems (which returns the  home
              dir  given the current user in your system). On Windows, it then
              checks for the APPDATA variable, or as a last resort the '%USER-
              PROFILE%\Application Data'.

              2)  On  windows, if there is no .curlrc file in the home dir, it
              checks for one in the same dir the curl executable is placed. On
              Unix-like  systems,  it will simply try to load .curlrc from the
              determined home dir.

              # --- Example file ---
              # this is a comment
              url = "example.com"
              output = "curlhere.html"
              user-agent = "superagent/1.0"

              # and fetch another URL too
              url = "example.com/docs/manpage.html"
              -O
              referer = "http://nowhereatall.example.com/"
              # --- End of example file ---

              This option can be used multiple times to load  multiple  config
              files.

       --connect-timeout <seconds>
              Maximum  time  in  seconds  that  you allow curl's connection to
              take.  This only limits the connection phase, so  if  curl  con-
              nects  within the given period it will continue - if not it will
              exit.  Since version 7.32.0, this option accepts decimal values.
              If this option is used several times, the last one will be used.

              See also -m, --max-time.

       --connect-to <HOST1:PORT1:HOST2:PORT2>

              For  a  request  to  the  given  HOST1:PORT1  pair,  connect  to
              HOST2:PORT2 instead.  This option is suitable to direct requests
              at a specific server, e.g. at a specific cluster node in a clus-
              ter  of  servers. This option is only used to establish the net-
              work connection. It does NOT affect the  hostname/port  that  is
              used for TLS/SSL (e.g. SNI, certificate verification) or for the
              application protocols. "HOST1" and  "PORT1"  may  be  the  empty
              string, meaning "any host/port". "HOST2" and "PORT2" may also be
              the  empty  string,  meaning   "use   the   request's   original
              host/port".

              A "host" specified to this option is compared as a string, so it
              needs to match the name used in request URL. It  can  be  either
              numerical such as "127.0.0.1" or the full host name such as "ex-
              ample.org".

              This option can be used many times to add many connect rules.

              See also --resolve and -H, --header. Added in 7.49.0.

       -C, --continue-at <offset>
              Continue/Resume a previous file transfer at  the  given  offset.
              The  given  offset  is  the  exact  number of bytes that will be
              skipped, counting from the beginning of the source  file  before
              it is transferred to the destination.  If used with uploads, the
              FTP server command SIZE will not be used by curl.

              Use "-C -" to tell curl to automatically find out  where/how  to
              resume  the  transfer. It then uses the given output/input files
              to figure that out.

              If this option is used several times, the last one will be used.

              See also -r, --range.

       -c, --cookie-jar <filename>
              (HTTP) Specify to which file you want curl to write all  cookies
              after  a  completed  operation. Curl writes all cookies from its
              in-memory cookie storage to the given file at the end of  opera-
              tions.  If  no  cookies  are known, no data will be written. The
              file will be written using the Netscape cookie file  format.  If
              you set the file name to a single dash, "-", the cookies will be
              written to stdout.

              This command line option will activate the  cookie  engine  that
              makes curl record and use cookies. Another way to activate it is
              to use the -b, --cookie option.

              If the cookie jar can't be created or written to, the whole curl
              operation  won't fail or even report an error clearly. Using -v,
              --verbose will get a warning displayed, but  that  is  the  only
              visible feedback you get about this possibly lethal situation.

              If  this  option  is used several times, the last specified file
              name will be used.

       -b, --cookie <data|filename>
              (HTTP) Pass the data to the HTTP server in the Cookie header. It
              is  supposedly the data previously received from the server in a
              "Set-Cookie:"  line.   The  data  should  be   in   the   format
              "NAME1=VALUE1; NAME2=VALUE2".

              If  no '=' symbol is used in the argument, it is instead treated
              as a filename to read previously stored cookie from. This option
              also activates the cookie engine which will make curl record in-
              coming cookies, which may be handy if you're using this in  com-
              bination  with  the  -L,  --location  option  or do multiple URL
              transfers on the same invoke. If the file name is exactly a  mi-
              nus ("-"), curl will instead read the contents from stdin.

              The file format of the file to read cookies from should be plain
              HTTP headers (Set-Cookie style) or the  Netscape/Mozilla  cookie
              file format.

              The  file  specified with -b, --cookie is only used as input. No
              cookies will be written to the file. To store cookies,  use  the
              -c, --cookie-jar option.

              Exercise  caution  if  you  are  using  this option and multiple
              transfers may occur.  If you use the NAME1=VALUE1; format, or in
              a  file  use  the  Set-Cookie format and don't specify a domain,
              then the cookie is sent for any domain (even after redirects are
              followed)  and cannot be modified by a server-set cookie. If the
              cookie engine is enabled and a server sets a cookie of the  same
              name then both will be sent on a future transfer to that server,
              likely not what you intended.  To address these issues set a do-
              main  in Set-Cookie (doing that will include sub domains) or use
              the Netscape format.

              If this option is used several times, the last one will be used.
              Users very often want to both read cookies from a file and write
              updated  cookies  back to a file, so using both -b, --cookie and
              -c, --cookie-jar in the same command line is common.

       --create-dirs
              When used in conjunction with the -o, --output option, curl will
              create  the  necessary local directory hierarchy as needed. This
              option creates the dirs mentioned with the -o, --output  option,
              nothing  else.  If  the --output file name uses no dir or if the
              dirs it mentions already exist, no dir will be created.

              Created dirs are made with mode 0750 on unix style file systems.
              To create remote directories when using FTP or SFTP, try  --ftp-
              create-dirs.

       --crlf (FTP  SMTP)  Convert  LF  to  CRLF  in  upload.  Useful  for MVS
              (OS/390).

              (SMTP added in 7.40.0)

       --crlfile <file>
              (TLS) Provide a file using PEM format with a Certificate Revoca-
              tion List that may specify peer certificates that are to be con-
              sidered revoked.

              If this option is used several times, the last one will be used.

              Added in 7.19.7.

       --data-ascii <data>
              (HTTP) This is just an alias for -d, --data.

       --data-binary <data>
              (HTTP) This posts data exactly as specified with no  extra  pro-
              cessing whatsoever.

              If  you  start  the data with the letter @, the rest should be a
              filename.  Data is posted in a  similar  manner  as  -d,  --data
              does,  except  that  newlines and carriage returns are preserved
              and conversions are never done.

              Like -d, --data the default content-type sent to the  server  is
              application/x-www-form-urlencoded.  If  you  want the data to be
              treated as arbitrary binary data by the server then set the con-
              tent-type  to octet-stream: -H "Content-Type: application/octet-
              stream".

              If this option is used several times,  the  ones  following  the
              first will append data as described in -d, --data.

       --data-raw <data>
              (HTTP)  This  posts data similarly to -d, --data but without the
              special interpretation of the @ character.

              See also -d, --data. Added in 7.43.0.

       --data-urlencode <data>
              (HTTP) This posts data, similar to the other -d, --data  options
              with the exception that this performs URL-encoding.

              To  be  CGI-compliant,  the <data> part should begin with a name
              followed by a separator and a content specification. The  <data>
              part can be passed to curl using one of the following syntaxes:

              content
                     This  will make curl URL-encode the content and pass that
                     on. Just be careful so that the content  doesn't  contain
                     any  =  or  @  symbols, as that will then make the syntax
                     match one of the other cases below!

              =content
                     This will make curl URL-encode the content and pass  that
                     on. The preceding = symbol is not included in the data.

              name=content
                     This  will make curl URL-encode the content part and pass
                     that on. Note that the name part is expected to  be  URL-
                     encoded already.

              @filename
                     This  will  make  curl load data from the given file (in-
                     cluding any newlines), URL-encode that data and  pass  it
                     on in the POST.

              name@filename
                     This  will  make  curl load data from the given file (in-
                     cluding any newlines), URL-encode that data and  pass  it
                     on  in  the  POST.  The  name part gets an equal sign ap-
                     pended, resulting in  name=urlencoded-file-content.  Note
                     that the name is expected to be URL-encoded already.
       See also -d, --data and --data-raw. Added in 7.18.0.

       -d, --data <data>
              (HTTP  MQTT)  Sends  the specified data in a POST request to the
              HTTP server, in the same way that a browser does when a user has
              filled  in an HTML form and presses the submit button. This will
              cause curl to pass the data to the server using the content-type
              application/x-www-form-urlencoded.  Compare to -F, --form.

              --data-raw is almost the same but does not have a special inter-
              pretation of the @ character. To post data  purely  binary,  you
              should  instead use the --data-binary option.  To URL-encode the
              value of a form field you may use --data-urlencode.

              If any of these options is used more than once on the same  com-
              mand  line,  the  data  pieces specified will be merged together
              with a separating  &-symbol.  Thus,  using  '-d  name=daniel  -d
              skill=lousy'  would  generate  a  post  chunk  that  looks  like
              'name=daniel&skill=lousy'.

              If you start the data with the letter @, the rest  should  be  a
              file  name  to read the data from, or - if you want curl to read
              the data from stdin. Posting data from  a  file  named  'foobar'
              would  thus  be done with -d, --data @foobar. When -d, --data is
              told to read from a file like that, carriage  returns  and  new-
              lines will be stripped out. If you don't want the @ character to
              have a special interpretation use --data-raw instead.

              See also --data-binary and --data-urlencode and --data-raw. This
              option  overrides  -F,  --form  and -I, --head and -T, --upload-
              file.

       --delegation <LEVEL>
              (GSS/kerberos) Set LEVEL to tell the server what it  is  allowed
              to delegate when it comes to user credentials.

              none   Don't allow any delegation.

              policy Delegates  if  and only if the OK-AS-DELEGATE flag is set
                     in the Kerberos service ticket,  which  is  a  matter  of
                     realm policy.

              always Unconditionally allow the server to delegate.

       --digest
              (HTTP)  Enables HTTP Digest authentication. This is an authenti-
              cation scheme that prevents the password from  being  sent  over
              the  wire in clear text. Use this in combination with the normal
              -u, --user option to set user name and password.

              If this option is used several times,  only  the  first  one  is
              used.

              See  also  -u, --user and --proxy-digest and --anyauth. This op-
              tion overrides --basic and --ntlm and --negotiate.

       --disable-eprt
              (FTP) Tell curl to disable the use of the EPRT and LPRT commands
              when doing active FTP transfers. Curl will normally always first
              attempt to use EPRT, then LPRT before using PORT, but with  this
              option,  it  will  use PORT right away. EPRT and LPRT are exten-
              sions to the original FTP protocol, and  may  not  work  on  all
              servers, but they enable more functionality in a better way than
              the traditional PORT command.

              --eprt can be used to explicitly enable EPRT again and --no-eprt
              is an alias for --disable-eprt.

              If  the  server is accessed using IPv6, this option will have no
              effect as EPRT is necessary then.

              Disabling EPRT only changes the active behavior. If you want  to
              switch  to  passive  mode  you need to not use -P, --ftp-port or
              force it with --ftp-pasv.

       --disable-epsv
              (FTP) (FTP) Tell curl to disable the use  of  the  EPSV  command
              when  doing  passive  FTP  transfers.  Curl will normally always
              first attempt to use EPSV before PASV, but with this option,  it
              will not try using EPSV.

              --epsv can be used to explicitly enable EPSV again and --no-epsv
              is an alias for --disable-epsv.

              If the server is an IPv6 host, this option will have  no  effect
              as EPSV is necessary then.

              Disabling EPSV only changes the passive behavior. If you want to
              switch to active mode you need to use -P, --ftp-port.

       -q, --disable
              If used as the first parameter on the command line,  the  curlrc
              config  file will not be read and used. See the -K, --config for
              details on the default config file search path.

       --disallow-username-in-url
              (HTTP) This tells curl to exit if  passed  a  url  containing  a
              username.

              See also --proto. Added in 7.61.0.

       --dns-interface <interface>
              (DNS)  Tell  curl  to send outgoing DNS requests through <inter-
              face>. This option is a counterpart to --interface  (which  does
              not  affect  DNS). The supplied string must be an interface name
              (not an address).

              See also --dns-ipv4-addr  and  --dns-ipv6-addr.  --dns-interface
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-ipv4-addr <address>
              (DNS) Tell curl to bind to <ip-address> when making IPv4 DNS re-
              quests,  so  that  the DNS requests originate from this address.
              The argument should be a single IPv4 address.

              See also --dns-interface  and  --dns-ipv6-addr.  --dns-ipv4-addr
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-ipv6-addr <address>
              (DNS) Tell curl to bind to <ip-address> when making IPv6 DNS re-
              quests,  so  that  the DNS requests originate from this address.
              The argument should be a single IPv6 address.

              See also --dns-interface  and  --dns-ipv4-addr.  --dns-ipv6-addr
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-servers <addresses>
              Set the list of DNS servers to be used instead of the system de-
              fault.   The  list of IP addresses should be separated with com-
              mas. Port numbers may also optionally be given as :<port-number>
              after each IP address.

              --dns-servers  requires that the underlying libcurl was built to
              support c-ares. Added in 7.33.0.

       --doh-url <URL>
              (all) Specifies which DNS-over-HTTPS (DOH) server to use to  re-
              solve  hostnames,  instead  of  using  the default name resolver
              mechanism. The URL must be HTTPS.

              If this option is used several times, the last one will be used.

              Added in 7.62.0.

       -D, --dump-header <filename>
              (HTTP FTP) Write the received protocol headers to the  specified
              file.

              This  option  is handy to use when you want to store the headers
              that an HTTP site sends to you. Cookies from the  headers  could
              then  be  read  in  a  second  curl  invocation by using the -b,
              --cookie option! The -c, --cookie-jar option is a better way  to
              store cookies.

              If  no  headers are received, the use of this option will create
              an empty file.

              When used in FTP, the FTP server response lines  are  considered
              being "headers" and thus are saved there.

              If this option is used several times, the last one will be used.

              See also -o, --output.

       --egd-file <file>
              (TLS)  Specify  the  path  name  to the Entropy Gathering Daemon
              socket. The socket is used to seed the  random  engine  for  SSL
              connections.

              See also --random-file.

       --engine <name>
              (TLS)  Select the OpenSSL crypto engine to use for cipher opera-
              tions. Use --engine list to print a list of build-time supported
              engines.  Note  that  not  all  (or  none) of the engines may be
              available at run-time.

       --etag-compare <file>
              (HTTP) This option makes a conditional HTTP request for the spe-
              cific ETag read from the given file by sending a custom If-None-
              Match header using the extracted ETag.

              For correct results, make sure that specified file contains only
              a single line with a desired ETag. An empty file is parsed as an
              empty ETag.

              Use the option --etag-save to first save the  ETag  from  a  re-
              sponse, and then use this option to compare using the saved ETag
              in a subsequent request.

              OMPARISON: There are 2 types of comparison or  ETags,  Weak  and
              Strong.  This option expects, and uses a strong comparison.

              Added in 7.68.0.

       --etag-save <file>
              (HTTP)  This  option  saves  an HTTP ETag to the specified file.
              Etag is usually part of headers  returned  by  a  request.  When
              server  sends  an  ETag, it must be enveloped by a double quote.
              This option extracts the ETag  without  the  double  quotes  and
              saves it into the <file>.

              A  server  can  send a week ETag which is prefixed by "W/". This
              identifier is not considered, and  only  relevant  ETag  between
              quotation marks is parsed.

              It an ETag wasn't send by the server or it cannot be parsed, and
              empty file is created.

              Added in 7.68.0.

       --expect100-timeout <seconds>
              (HTTP) Maximum time in seconds that you allow curl to wait for a
              100-continue  response  when curl emits an Expects: 100-continue
              header in its request. By default curl  will  wait  one  second.
              This  option accepts decimal values! When curl stops waiting, it
              will continue as if the response has been received.

              See also --connect-timeout. Added in 7.47.0.

       --fail-early
              Fail and exit on the first detected transfer error.

              When curl is used to do multiple transfers on the command  line,
              it will attempt to operate on each given URL, one by one. By de-
              fault, it will ignore errors if there are more  URLs  given  and
              the  last  URL's  success will determine the error code curl re-
              turns. So early failures will be "hidden" by subsequent success-
              ful transfers.

              Using  this  option,  curl  will  instead return an error on the
              first transfer that fails, independent of  the  amount  of  URLs
              that  are given on the command line. This way, no transfer fail-
              ures go undetected by scripts and similar.

              This option is global and does not need to be specified for each
              use of -:, --next.

              This option does not imply -f, --fail, which causes transfers to
              fail due to the server's HTTP status code. You can  combine  the
              two options, however note -f, --fail is not global and is there-
              fore contained by -:, --next.

              Added in 7.52.0.

       -f, --fail
              (HTTP) Fail silently (no output at all) on server  errors.  This
              is  mostly done to better enable scripts etc to better deal with
              failed attempts. In normal cases when an HTTP  server  fails  to
              deliver  a  document,  it  returns  an  HTML document stating so
              (which often also describes why and more). This flag  will  pre-
              vent curl from outputting that and return error 22.

              This  method is not fail-safe and there are occasions where non-
              successful response codes will slip through, especially when au-
              thentication is involved (response codes 401 and 407).

       --false-start
              (TLS)  Tells  curl  to use false start during the TLS handshake.
              False start is a mode where a TLS client will start sending  ap-
              plication  data  before verifying the server's Finished message,
              thus saving a round trip when performing a full handshake.

              This is currently only implemented in the NSS and Secure  Trans-
              port (on iOS 7.0 or later, or OS X 10.9 or later) backends.

              Added in 7.42.0.

       --form-string <name=string>
              (HTTP  SMTP  IMAP)  Similar  to -F, --form except that the value
              string for the named parameter is used  literally.  Leading  '@'
              and '<' characters, and the ';type=' string in the value have no
              special meaning. Use this in preference to -F, --form if there's
              any  possibility  that the string value may accidentally trigger
              the '@' or '<' features of -F, --form.

              See also -F, --form.

       -F, --form <name=content>
              (HTTP SMTP IMAP) For HTTP protocol family, this lets  curl  emu-
              late  a  filled-in  form  in which a user has pressed the submit
              button. This causes curl to POST  data  using  the  Content-Type
              multipart/form-data according to RFC 2388.

              For  SMTP and IMAP protocols, this is the mean to compose a mul-
              tipart mail message to transmit.

              This enables uploading of binary files etc. To force  the  'con-
              tent' part to be a file, prefix the file name with an @ sign. To
              just get the content part from a file, prefix the file name with
              the  symbol  <.  The  difference  between @ and < is then that @
              makes a file get attached in the post as a  file  upload,  while
              the < makes a text field and just get the contents for that text
              field from a file.

              Tell curl to read content from stdin instead of a file by  using
              - as filename. This goes for both @ and < constructs. When stdin
              is used, the contents is buffered in memory first by curl to de-
              termine its size and allow a possible resend.  Defining a part's
              data from a named non-regular file (such as a named pipe or sim-
              ilar)  is unfortunately not subject to buffering and will be ef-
              fectively read at transmission time; since the full size is  un-
              known before the transfer starts, such data is sent as chunks by
              HTTP and rejected by IMAP.

              Example: send an image to an HTTP server, where 'profile' is the
              name  of  the  form-field to which the file portrait.jpg will be
              the input:

               curl -F profile=@portrait.jpg https://example.com/upload.cgi

              Example: send your name and shoe size in two text fields to  the
              server:

               curl -F name=John -F shoesize=11 https://example.com/

              Example:  send your essay in a text field to the server. Send it
              as a plain text field, but get the contents for it from a  local
              file:

               curl -F "story=<hugefile.txt" https://example.com/

              You  can  also  tell  curl  what  Content-Type  to  use by using
              'type=', in a manner similar to:

               curl -F "web=@index.html;type=text/html" example.com

              or

               curl -F "name=daniel;type=text/foo" example.com

              You can also explicitly change the name field of a  file  upload
              part by setting filename=, like this:

               curl -F "file=@localfile;filename=nameinpost" example.com

              If  filename/path contains ',' or ';', it must be quoted by dou-
              ble-quotes like:

               curl  -F  "file=@\"localfile\";filename=\"nameinpost\""   exam-
              ple.com

              or

               curl -F 'file=@"localfile";filename="nameinpost"' example.com

              Note  that  if  a  filename/path is quoted by double-quotes, any
              double-quote or backslash within the filename must be escaped by
              backslash.

              Quoting  must  also  be  applied to non-file data if it contains
              semicolons, leading/trailing spaces or leading double quotes:

               curl -F  'colors="red;  green;  blue";type=text/x-myapp'  exam-
              ple.com

              You  can  add  custom  headers to the field by setting headers=,
              like

                curl -F "submit=OK;headers=\"X-submit-type: OK\"" example.com

              or

                curl -F "submit=OK;headers=@headerfile" example.com

              The headers= keyword may appear more that once and  above  notes
              about  quoting  apply.  When headers are read from a file, Empty
              lines and lines starting with '#' are comments and ignored; each
              header can be folded by splitting between two words and starting
              the continuation line with a  space;  embedded  carriage-returns
              and  trailing  spaces  are  stripped.   Here  is an example of a
              header file contents:

                # This file contain two headers.
                X-header-1: this is a header

                # The following header is folded.
                X-header-2: this is
                 another header

              To support sending multipart mail messages, the  syntax  is  ex-
              tended as follows:
              -  name can be omitted: the equal sign is the first character of
              the argument,
              - if data starts with '(', this signals to start  a  new  multi-
              part: it can be followed by a content type specification.
              - a multipart can be terminated with a '=)' argument.

              Example:  the  following  command sends an SMTP mime e-mail con-
              sisting in an inline part in two alternative formats: plain text
              and HTML. It attaches a text file:

               curl -F '=(;type=multipart/alternative' \
                       -F '=plain text message' \
                       -F '= <body>HTML message</body>;type=text/html' \
                    -F '=)' -F '=@textfile.txt' ...  smtp://example.com

              Data  can  be encoded for transfer using encoder=. Available en-
              codings are binary and 8bit that do nothing else than adding the
              corresponding  Content-Transfer-Encoding  header, 7bit that only
              rejects 8-bit characters with a transfer error, quoted-printable
              and  base64  that  encodes  data  according to the corresponding
              schemes, limiting lines length to 76 characters.

              Example: send multipart mail with a quoted-printable  text  mes-
              sage and a base64 attached file:

               curl -F '=text message;encoder=quoted-printable' \
                    -F '=@localfile;encoder=base64' ... smtp://example.com

              See further examples and details in the MANUAL.

              This option can be used multiple times.

              This  option  overrides  -d, --data and -I, --head and -T, --up-
              load-file.

       --ftp-account <data>
              (FTP) When an FTP server asks for "account data" after user name
              and  password has been provided, this data is sent off using the
              ACCT command.

              If this option is used several times, the last one will be used.

              Added in 7.13.0.

       --ftp-alternative-to-user <command>
              (FTP) If authenticating with the USER and PASS  commands  fails,
              send  this  command.   When  connecting  to  Tumbleweed's Secure
              Transport server over FTPS using  a  client  certificate,  using
              "SITE  AUTH"  will tell the server to retrieve the username from
              the certificate.
              Added in 7.15.5.

       --ftp-create-dirs
              (FTP SFTP) When an FTP or SFTP URL/operation uses  a  path  that
              doesn't  currently exist on the server, the standard behavior of
              curl is to fail. Using this option, curl will instead attempt to
              create missing directories.

              See also --create-dirs.

       --ftp-method <method>
              (FTP)  Control what method curl should use to reach a file on an
              FTP(S) server. The method argument should be one of the  follow-
              ing alternatives:

              multicwd
                     curl  does  a  single CWD operation for each path part in
                     the given URL. For deep hierarchies this means very  many
                     commands.  This  is  how RFC 1738 says it should be done.
                     This is the default but the slowest behavior.

              nocwd  curl does no CWD at all. curl will do  SIZE,  RETR,  STOR
                     etc and give a full path to the server for all these com-
                     mands. This is the fastest behavior.

              singlecwd
                     curl does one CWD with the full target directory and then
                     operates  on  the  file  "normally" (like in the multicwd
                     case). This is somewhat  more  standards  compliant  than
                     'nocwd' but without the full penalty of 'multicwd'.

       Added in 7.15.1.

       --ftp-pasv
              (FTP)  Use  passive mode for the data connection. Passive is the
              internal default behavior, but using this option can be used  to
              override a previous -P, --ftp-port option.

              If  this  option  is  used  several times, only the first one is
              used. Undoing an enforced passive really isn't  doable  but  you
              must then instead enforce the correct -P, --ftp-port again.

              Passive mode means that curl will try the EPSV command first and
              then PASV, unless --disable-epsv is used.
              See also --disable-epsv. Added in 7.11.0.

       -P, --ftp-port <address>
              (FTP) Reverses the default initiator/listener  roles  when  con-
              necting  with  FTP. This option makes curl use active mode. curl
              then tells the server to connect back to the client's  specified
              address and port, while passive mode asks the server to setup an
              IP address and port for it to connect to.  <address>  should  be
              one of:

              interface
                     e.g.  "eth0"  to specify which interface's IP address you
                     want to use (Unix only)

              IP address
                     e.g. "192.168.10.1" to specify the exact IP address

              host name
                     e.g. "my.host.domain" to specify the machine

              -      make curl pick the same IP address that is  already  used
                     for the control connection

       If  this  option is used several times, the last one will be used. Dis-
       able the use of PORT with --ftp-pasv. Disable the attempt  to  use  the
       EPRT  command  instead  of PORT by using --disable-eprt. EPRT is really
       PORT++.

       Since 7.19.5, you can append ":[start]-[end]" to the right of  the  ad-
       dress,  to tell curl what TCP port range to use. That means you specify
       a port range, from a lower to a higher number. A single number works as
       well,  but do note that it increases the risk of failure since the port
       may not be available.

       See also --ftp-pasv and --disable-eprt.

       --ftp-pret
              (FTP) Tell curl to send a PRET command before PASV  (and  EPSV).
              Certain  FTP  servers,  mainly drftpd, require this non-standard
              command for directory listings as well as up  and  downloads  in
              PASV mode.

              Added in 7.20.0.

       --ftp-skip-pasv-ip
              (FTP) Tell curl to not use the IP address the server suggests in
              its response to curl's PASV command when curl connects the  data
              connection.  Instead curl will re-use the same IP address it al-
              ready uses for the control connection.

              This option has no effect if PORT, EPRT or EPSV is used  instead
              of PASV.

              See also --ftp-pasv. Added in 7.14.2.

       --ftp-ssl-ccc-mode <active/passive>
              (FTP)  Sets the CCC mode. The passive mode will not initiate the
              shutdown, but instead wait for the server to do it, and will not
              reply to the shutdown from the server. The active mode initiates
              the shutdown and waits for a reply from the server.

              See also --ftp-ssl-ccc. Added in 7.16.2.

       --ftp-ssl-ccc
              (FTP) Use CCC (Clear Command Channel)  Shuts  down  the  SSL/TLS
              layer after authenticating. The rest of the control channel com-
              munication will be unencrypted. This allows NAT routers to  fol-
              low the FTP transaction. The default mode is passive.

              See also --ssl and --ftp-ssl-ccc-mode. Added in 7.16.1.

       --ftp-ssl-control
              (FTP)  Require  SSL/TLS  for  the FTP login, clear for transfer.
              Allows secure authentication, but non-encrypted  data  transfers
              for  efficiency.   Fails the transfer if the server doesn't sup-
              port SSL/TLS.

              Added in 7.16.0.

       -G, --get
              When used, this option will make all  data  specified  with  -d,
              --data,  --data-binary or --data-urlencode to be used in an HTTP
              GET request instead of the POST request that otherwise would  be
              used. The data will be appended to the URL with a '?' separator.
              If  used  in combination with -I, --head, the POST data will in-
              stead be appended to the URL with a HEAD request.

              If this option is used several times,  only  the  first  one  is
              used.  This is because undoing a GET doesn't make sense, but you
              should then instead enforce the alternative method you prefer.

       -g, --globoff
              This option switches off the "URL globbing parser". When you set
              this  option, you can specify URLs that contain the letters {}[]
              without having them being interpreted by curl itself. Note  that
              these  letters are not normal legal URL contents but they should
              be encoded according to the URI standard.

       --happy-eyeballs-timeout-ms <milliseconds>
              Happy eyeballs is an algorithm that attempts to connect to  both
              IPv4  and  IPv6  addresses for dual-stack hosts, preferring IPv6
              first for the number of milliseconds. If the IPv6 address cannot
              be  connected  to  within that time then a connection attempt is
              made to the IPv4 address in parallel. The first connection to be
              established is the one that is used.

              The  range of suggested useful values is limited. Happy Eyeballs
              RFC 6555 says "It is RECOMMENDED  that  connection  attempts  be
              paced  150-250 ms apart to balance human factors against network
              load." libcurl currently defaults to 200 ms. Firefox and  Chrome
              currently default to 300 ms.

              If this option is used several times, the last one will be used.

              Added in 7.59.0.

       --haproxy-protocol
              (HTTP)  Send a HAProxy PROXY protocol v1 header at the beginning
              of the connection. This is used by some load balancers  and  re-
              verse proxies to indicate the client's true IP address and port.
              This  option is primarily useful when sending test requests to a
              service that expects this header.

              Added in 7.60.0.

       -I, --head
              (HTTP FTP FILE) Fetch the headers only! HTTP-servers feature the
              command  HEAD which this uses to get nothing but the header of a
              document. When used on an FTP or FILE file,  curl  displays  the
              file size and last modification time only.

       -H, --header <header/@file>
              (HTTP)  Extra header to include in the request when sending HTTP
              to a server. You may specify any number of extra  headers.  Note
              that if you should add a custom header that has the same name as
              one of the internal ones curl would  use,  your  externally  set
              header will be used instead of the internal one. This allows you
              to make even trickier stuff than curl  would  normally  do.  You
              should  not  replace internally set headers without knowing per-
              fectly well what you're doing. Remove an internal header by giv-
              ing  a  replacement  without  content  on  the right side of the
              colon, as in: -H "Host:". If you send the custom header with no-
              value  then its header must be terminated with a semicolon, such
              as -H "X-Custom-Header;" to send "X-Custom-Header:".

              curl will make sure that each header  you  add/replace  is  sent
              with the proper end-of-line marker, you should thus not add that
              as a part of the header content: do not add newlines or carriage
              returns, they will only mess things up for you.

              Starting  in  7.55.0, this option can take an argument in @file-
              name style, which then adds a header for each line in the  input
              file. Using @- will make curl read the header file from stdin.

              See also the -A, --user-agent and -e, --referer options.

              Starting in 7.37.0, you need --proxy-header to send custom head-
              ers intended for a proxy.

              Example:

               curl -H "X-First-Name: Joe" http://example.com/

              WARNING: headers set with this option will be  set  in  all  re-
              quests  - even after redirects are followed, like when told with
              -L, --location. This can lead to the header being sent to  other
              hosts  than  the  original  host, so sensitive headers should be
              used with caution combined with following redirects.

              This option can be used  multiple  times  to  add/replace/remove
              multiple headers.

       -h, --help
              Usage  help.  This lists all current command line options with a
              short description.
       --hostpubmd5 <md5>
              (SFTP SCP) Pass a string containing 32 hexadecimal  digits.  The
              string  should  be the 128 bit MD5 checksum of the remote host's
              public key, curl will refuse the connection with the host unless
              the md5sums match.

              Added in 7.17.1.

       --http0.9
              (HTTP) Tells curl to be fine with HTTP version 0.9 response.

              HTTP/0.9  is  a completely headerless response and therefore you
              can also connect with this to non-HTTP servers and still  get  a
              response since curl will simply transparently downgrade - if al-
              lowed.

              Since curl 7.66.0, HTTP/0.9 is disabled by default.

       -0, --http1.0
              (HTTP) Tells curl to use HTTP version 1.0 instead of  using  its
              internally preferred HTTP version.

              This option overrides --http1.1 and --http2.

       --http1.1
              (HTTP) Tells curl to use HTTP version 1.1.

              This  option  overrides  -0,  --http1.0  and  --http2.  Added in
              7.33.0.

       --http2-prior-knowledge
              (HTTP) Tells curl to  issue  its  non-TLS  HTTP  requests  using
              HTTP/2  without  HTTP/1.1  Upgrade.  It requires prior knowledge
              that the server supports HTTP/2 straight  away.  HTTPS  requests
              will  still  do HTTP/2 the standard way with negotiated protocol
              version in the TLS handshake.

              --http2-prior-knowledge requires that the underlying libcurl was
              built to support HTTP/2. This option overrides --http1.1 and -0,
              --http1.0 and --http2. Added in 7.49.0.

       --http2
              (HTTP) Tells curl to use HTTP version 2.

              See also --http1.1 and --http3. --http2 requires that the under-
              lying libcurl was built to support HTTP/2. This option overrides
              --http1.1 and -0, --http1.0 and  --http2-prior-knowledge.  Added
              in 7.33.0.

       --http3
              (HTTP)  WARNING: this option is experimental. Do not use in pro-
              duction.

              Tells curl to use HTTP version 3 directly to the host  and  port
              number used in the URL. A normal HTTP/3 transaction will be done
              to a host and then get redirected via Alt-SVc, but  this  option
              allows  a  user to circumvent that when you know that the target
              speaks HTTP/3 on the given host and port.

              This option will make curl fail if a QUIC connection  cannot  be
              established,  it cannot fall back to a lower HTTP version on its
              own.

              See also --http1.1 and --http2. --http3 requires that the under-
              lying libcurl was built to support HTTP/3. This option overrides
              --http1.1 and -0, --http1.0 and --http2 and --http2-prior-knowl-
              edge. Added in 7.66.0.

       --ignore-content-length
              (FTP  HTTP)  For HTTP, Ignore the Content-Length header. This is
              particularly useful for servers running Apache 1.x,  which  will
              report  incorrect  Content-Length  for files larger than 2 giga-
              bytes.

              For FTP (since 7.46.0), skip the RETR command to figure out  the
              size before downloading a file.

       -i, --include
              Include  the  HTTP  response headers in the output. The HTTP re-
              sponse headers can include things  like  server  name,  cookies,
              date of the document, HTTP version and more...

              To view the request headers, consider the -v, --verbose option.

              See also -v, --verbose.

       -k, --insecure
              (TLS) By default, every SSL connection curl makes is verified to
              be secure. This option allows curl to proceed and  operate  even
              for server connections otherwise considered insecure.

              The  server  connection  is verified by making sure the server's
              certificate contains the right name  and  verifies  successfully
              using the cert store.

              See this online resource for further details:
               https://curl.haxx.se/docs/sslcerts.html
              See also --proxy-insecure and --cacert.

       --interface <name>

              Perform  an operation using a specified interface. You can enter
              interface name, IP address or host name. An example  could  look
              like:

               curl --interface eth0:1 https://www.example.com/

              If this option is used several times, the last one will be used.
              On  Linux  it can be used to specify a VRF, but the binary needs
              to either have CAP_NET_RAW or to be run as root.  More  informa-
              tion   about  Linux  VRF:  https://www.kernel.org/doc/Documenta-
              tion/networking/vrf.txt

              See also --dns-interface.

       -4, --ipv4
              This option tells curl to resolve names to IPv4 addresses  only,
              and not for example try IPv6.

              See  also  --http1.1  and  --http2.  This  option  overrides -6,
              --ipv6.

       -6, --ipv6
              This option tells curl to resolve names to IPv6 addresses  only,
              and not for example try IPv4.

              See  also  --http1.1  and  --http2.  This  option  overrides -4,
              --ipv4.

       -j, --junk-session-cookies
              (HTTP) When curl is told to read cookies from a given file, this
              option will make it discard all "session cookies". This will ba-
              sically have the same effect as if a  new  session  is  started.
              Typical  browsers  always  discard  session cookies when they're
              closed down.

              See also -b, --cookie and -c, --cookie-jar.

       --keepalive-time <seconds>
              This option sets the time a connection needs to remain idle  be-
              fore  sending  keepalive  probes and the time between individual
              keepalive probes. It is currently effective on operating systems
              offering  the  TCP_KEEPIDLE  and  TCP_KEEPINTVL  socket  options
              (meaning Linux, recent AIX, HP-UX and more). This option has  no
              effect if --no-keepalive is used.

              If this option is used several times, the last one will be used.
              If unspecified, the option defaults to 60 seconds.

              Added in 7.18.0.

       --key-type <type>
              (TLS) Private key file type. Specify which type your --key  pro-
              vided  private  key  is. DER, PEM, and ENG are supported. If not
              specified, PEM is assumed.

              If this option is used several times, the last one will be used.

       --key <key>
              (TLS SSH) Private key file name. Allows you to provide your pri-
              vate  key in this separate file. For SSH, if not specified, curl
              tries  the  following  candidates  in  order:   '~/.ssh/id_rsa',
              '~/.ssh/id_dsa', './id_rsa', './id_dsa'.

              If  curl is built against OpenSSL library, and the engine pkcs11
              is available, then a PKCS#11 URI (RFC 7512) can be used to spec-
              ify  a  private key located in a PKCS#11 device. A string begin-
              ning with "pkcs11:" will be interpreted as a PKCS#11 URI.  If  a
              PKCS#11 URI is provided, then the --engine option will be set as
              "pkcs11" if none was provided and the --key-type option will  be
              set as "ENG" if none was provided.

              If this option is used several times, the last one will be used.

       --krb <level>
              (FTP)  Enable Kerberos authentication and use. The level must be
              entered and should be one of 'clear', 'safe', 'confidential', or
              'private'.  Should  you  use  a  level that is not one of these,
              'private' will instead be used.

              If this option is used several times, the last one will be used.
              --krb requires that the underlying libcurl was built to  support
              Kerberos.

       --libcurl <file>
              Append  this  option  to any ordinary curl command line, and you
              will get a libcurl-using C source code written to the file  that
              does the equivalent of what your command-line operation does!

              If  this  option is used several times, the last given file name
              will be used.

              Added in 7.16.1.

       --limit-rate <speed>
              Specify the maximum transfer rate you want curl  to  use  -  for
              both downloads and uploads. This feature is useful if you have a
              limited pipe and you'd like your transfer not to use your entire
              bandwidth. To make it slower than it otherwise would be.

              The  given speed is measured in bytes/second, unless a suffix is
              appended.  Appending 'k' or 'K' will count the number  as  kilo-
              bytes,  'm' or 'M' makes it megabytes, while 'g' or 'G' makes it
              gigabytes. Examples: 200K, 3m and 1G.

              If you also use the -Y, --speed-limit option, that  option  will
              take precedence and might cripple the rate-limiting slightly, to
              help keeping the speed-limit logic working.

              If this option is used several times, the last one will be used.

       -l, --list-only
              (FTP POP3) (FTP) When listing  an  FTP  directory,  this  switch
              forces  a  name-only view. This is especially useful if the user
              wants to machine-parse the contents of an  FTP  directory  since
              the normal directory view doesn't use a standard look or format.
              When used like this, the option causes a NLST command to be sent
              to the server instead of LIST.

              Note:  Some  FTP  servers  list  only files in their response to
              NLST; they do not include sub-directories and symbolic links.

              (POP3) When retrieving a specific email from POP3,  this  switch
              forces  a  LIST command to be performed instead of RETR. This is
              particularly useful if the user wants to see if a specific  mes-
              sage id exists on the server and what size it is.

              Note:  When combined with -X, --request, this option can be used
              to send an UIDL command instead, so the user may use the email's
              unique  identifier  rather  than it's message id to make the re-
              quest.

              Added in 4.0.

       --local-port <num/range>
              Set a preferred single number or range (FROM-TO) of  local  port
              numbers to use for the connection(s).  Note that port numbers by
              nature are a scarce resource that will be busy at times so  set-
              ting  this range to something too narrow might cause unnecessary
              connection setup failures.

              Added in 7.15.2.

       --location-trusted
              (HTTP) Like -L, --location, but will allow sending  the  name  +
              password to all hosts that the site may redirect to. This may or
              may not introduce a security breach if the site redirects you to
              a  site  to which you'll send your authentication info (which is
              plaintext in the case of HTTP Basic authentication).

              See also -u, --user.

       -L, --location
              (HTTP) If the server reports that the requested page  has  moved
              to a different location (indicated with a Location: header and a
              3XX response code), this option will make curl redo the  request
              on  the  new  place.  If used together with -i, --include or -I,
              --head, headers from all requested pages will be shown. When au-
              thentication  is  used,  curl  only sends its credentials to the
              initial host. If a redirect takes curl to a different  host,  it
              won't  be  able to intercept the user+password. See also --loca-
              tion-trusted on how to change this. You can limit the amount  of
              redirects to follow by using the --max-redirs option.

              When  curl  follows  a redirect and if the request is a POST, it
              will do the following request with a GET if  the  HTTP  response
              was  301,  302,  or  303. If the response code was any other 3xx
              code, curl will re-send the following request using the same un-
              modified method.

              You can tell curl to not change POST requests to GET after a 30x
              response by using the dedicated  options  for  that:  --post301,
              --post302 and --post303.

              The  method  set  with  -X,  --request overrides the method curl
              would otherwise select to use.

       --login-options <options>
              (IMAP POP3 SMTP) Specify the login options to use during  server
              authentication.

              You  can  use the login options to specify protocol specific op-
              tions that may be used during authentication.  At  present  only
              IMAP,  POP3 and SMTP support login options. For more information
              about the login options please see RFC 2384, RFC 5092  and  IETF
              draft draft-earhart-url-smtp-00.txt

              If this option is used several times, the last one will be used.

              Added in 7.34.0.

       --mail-auth <address>
              (SMTP)  Specify  a  single address. This will be used to specify
              the authentication address (identity)  of  a  submitted  message
              that is being relayed to another server.

              See also --mail-rcpt and --mail-from. Added in 7.25.0.

       --mail-from <address>
              (SMTP)  Specify  a single address that the given mail should get
              sent from.

              See also --mail-rcpt and --mail-auth. Added in 7.20.0.

       --mail-rcpt-allowfails
              (SMTP) When sending data to multiple recipients, by default curl
              will  abort  SMTP conversation if at least one of the recipients
              causes RCPT TO command to return an error.

              The default behavior can be changed by  passing  --mail-rcpt-al-
              lowfails  command-line option which will make curl ignore errors
              and proceed with the remaining valid recipients.

              In case when all recipients cause RCPT TO command to fail,  curl
              will  abort SMTP conversation and return the error received from
              to the last RCPT TO command.  Added in 7.69.0.

       --mail-rcpt <address>
              (SMTP) Specify a single address, user name or mailing list name.
              Repeat this option several times to send to multiple recipients.
              When  performing a mail transfer, the recipient should specify a
              valid email address to send the mail to.

              When performing an address verification (VRFY command), the  re-
              cipient  should  be  specified as the user name or user name and
              domain (as per Section 3.5 of RFC5321). (Added in 7.34.0)

              When performing a mailing list expand (EXPN command), the recip-
              ient  should  be  specified using the mailing list name, such as
              "Friends" or "London-Office".  (Added in 7.34.0)

              Added in 7.20.0.

       -M, --manual
              Manual. Display the huge help text.

       --max-filesize <bytes>
              Specify the maximum size (in bytes) of a file  to  download.  If
              the  file requested is larger than this value, the transfer will
              not start and curl will return with exit code 63.

              A size modifier may be used. For example, Appending 'k'  or  'K'
              will  count  the  number  as  kilobytes,  'm'  or  'M'  makes it
              megabytes, while 'g' or 'G' makes it gigabytes. Examples:  200K,
              3m and 1G. (Added in 7.58.0)

              NOTE:  The  file size is not always known prior to download, and
              for such files this option has no effect even if the file trans-
              fer  ends  up  being larger than this given limit. This concerns
              both FTP and HTTP transfers.

              See also --limit-rate.

       --max-redirs <num>
              (HTTP) Set maximum  number  of  redirection-followings  allowed.
              When  -L,  --location is used, is used to prevent curl from fol-
              lowing redirections too much. By default, the limit is set to 50
              redirections. Set this option to -1 to make it unlimited.

              If this option is used several times, the last one will be used.

       -m, --max-time <seconds>
              Maximum  time  in  seconds that you allow the whole operation to
              take.  This is useful for preventing your batch jobs from  hang-
              ing  for  hours due to slow networks or links going down.  Since
              7.32.0, this option accepts decimal values, but the actual time-
              out will decrease in accuracy as the specified timeout increases
              in decimal precision.

              If this option is used several times, the last one will be used.

              See also --connect-timeout.

       --metalink
              This option can tell curl to parse and process a  given  URI  as
              Metalink  file  (both  version 3 and 4 (RFC 5854) are supported)
              and make use of the mirrors listed within for failover if  there
              are  errors (such as the file or server not being available). It
              will also verify the hash of the file after  the  download  com-
              pletes.  The Metalink file itself is downloaded and processed in
              memory and not stored in the local file system.

              Example to use a remote Metalink file:

               curl --metalink http://www.example.com/example.metalink

              To use a Metalink file in the local file system, use FILE proto-
              col (file://):

               curl --metalink file://example.metalink

              Please  note  that if FILE protocol is disabled, there is no way
              to use a local Metalink file at the time of this  writing.  Also
              note  that  if  --metalink  and -i, --include are used together,
              --include will be ignored. This is because including headers  in
              the  response  will break Metalink parser and if the headers are
              included in the file described in Metalink file, hash check will
              fail.

              --metalink  requires  that  the  underlying libcurl was built to
              support metalink. Added in 7.27.0.

       --negotiate
              (HTTP) Enables Negotiate (SPNEGO) authentication.

              This option requires a library built with GSS-API or  SSPI  sup-
              port.  Use  -V,  --version  to  see  if  your curl supports GSS-
              API/SSPI or SPNEGO.

              When using this option, you must also provide a fake -u,  --user
              option  to  activate the authentication code properly. Sending a
              '-u :' is enough as the user name  and  password  from  the  -u,
              --user option aren't actually used.

              If  this  option  is  used  several times, only the first one is
              used.

              See also --basic and --ntlm and --anyauth and --proxy-negotiate.

       --netrc-file <filename>
              This option is similar to -n, --netrc, except that  you  provide
              the  path  (absolute  or  relative)  to the netrc file that curl
              should use.  You can only specify one netrc file per invocation.
              If  several --netrc-file options are provided, the last one will
              be used.

              It will abide by --netrc-optional if specified.

              This option overrides -n, --netrc. Added in 7.21.5.

       --netrc-optional
              Very similar to -n, --netrc, but this option  makes  the  .netrc
              usage optional and not mandatory as the -n, --netrc option does.

              See also --netrc-file. This option overrides -n, --netrc.

       -n, --netrc
              Makes  curl  scan  the  .netrc  (_netrc  on Windows) file in the
              user's home directory for login name and password. This is typi-
              cally  used for FTP on Unix. If used with HTTP, curl will enable
              user authentication. See netrc(5) ftp(1) for details on the file
              format.  Curl  will  not  complain if that file doesn't have the
              right permissions (it should not be either world- or group-read-
              able).  The environment variable "HOME" is used to find the home
              directory.

              A quick and very simple example of how to setup a .netrc to  al-
              low  curl  to  FTP to the machine host.domain.com with user name
              'myself' and password 'secret' should look similar to:

              machine host.domain.com login myself password secret

       -:, --next
              Tells curl to use a separate operation for the following URL and
              associated  options.  This  allows  you  to send several URL re-
              quests, each with their own specific options, for example,  such
              as different user names or custom requests for each.

              -:,  --next  will  reset  all local options and only global ones
              will have their values survive over to the  operation  following
              the  -:,  --next  instruction. Global options include -v, --ver-
              bose, --trace, --trace-ascii and --fail-early.

              For example, you can do both a GET and a POST in a  single  com-
              mand line:

               curl www1.example.com --next -d postthis www2.example.com

              Added in 7.36.0.

       --no-alpn
              (HTTPS)  Disable  the ALPN TLS extension. ALPN is enabled by de-
              fault if libcurl was built with an  SSL  library  that  supports
              ALPN.  ALPN is used by a libcurl that supports HTTP/2 to negoti-
              ate HTTP/2 support with the server during https sessions.

              See also --no-npn and --http2. --no-alpn requires that  the  un-
              derlying libcurl was built to support TLS. Added in 7.36.0.

       -N, --no-buffer
              Disables the buffering of the output stream. In normal work sit-
              uations, curl will use a standard buffered  output  stream  that
              will have the effect that it will output the data in chunks, not
              necessarily exactly when the data arrives.   Using  this  option
              will disable that buffering.

              Note  that  this  is the negated option name documented. You can
              thus use --buffer to enforce the buffering.

       --no-keepalive
              Disables the use of keepalive messages on  the  TCP  connection.
              curl otherwise enables them by default.

              Note  that  this  is the negated option name documented. You can
              thus use --keepalive to enforce keepalive.

       --no-npn
              (HTTPS) Disable the NPN TLS extension. NPN is enabled by default
              if  libcurl was built with an SSL library that supports NPN. NPN
              is used by a libcurl that supports HTTP/2  to  negotiate  HTTP/2
              support with the server during https sessions.

              See  also  --no-alpn and --http2. --no-npn requires that the un-
              derlying libcurl was built to support TLS. Added in 7.36.0.

       --no-progress-meter
              Option to switch off the progress meter output without muting or
              otherwise  affecting warning and informational messages like -s,
              --silent does.

              Note that this is the negated option name  documented.  You  can
              thus use --progress-meter to enable the progress meter again.

              See also -v, --verbose and -s, --silent. Added in 7.67.0.

       --no-sessionid
              (TLS)  Disable curl's use of SSL session-ID caching.  By default
              all transfers are done using the cache. Note that while  nothing
              should  ever  get  hurt  by attempting to reuse SSL session-IDs,
              there seem to be broken SSL implementations in the wild that may
              require you to disable this in order for you to succeed.

              Note  that  this  is the negated option name documented. You can
              thus use --sessionid to enforce session-ID caching.

              Added in 7.16.0.

       --noproxy <no-proxy-list>
              Comma-separated list of hosts which do not use a proxy,  if  one
              is  specified.  The only wildcard is a single * character, which
              matches all hosts, and effectively disables the proxy. Each name
              in  this  list  is matched as either a domain which contains the
              hostname, or the hostname itself. For example,  local.com  would
              match   local.com,  local.com:80,  and  www.local.com,  but  not
              www.notlocal.com.

              Since 7.53.0, This option overrides  the  environment  variables
              that  disable the proxy. If there's an environment variable dis-
              abling a proxy, you can set noproxy list to "" to override it.

              Added in 7.19.4.

       --ntlm-wb
              (HTTP) Enables NTLM much in the style --ntlm does, but hand over
              the  authentication  to the separate binary ntlmauth application
              that is executed when needed.

              See also --ntlm and --proxy-ntlm.

       --ntlm (HTTP) Enables  NTLM  authentication.  The  NTLM  authentication
              method was designed by Microsoft and is used by IIS web servers.
              It is a proprietary protocol, reverse-engineered by clever  peo-
              ple and implemented in curl based on their efforts. This kind of
              behavior should not be endorsed, you should  encourage  everyone
              who  uses  NTLM to switch to a public and documented authentica-
              tion method instead, such as Digest.

              If you want to enable NTLM for your proxy  authentication,  then
              use --proxy-ntlm.

              If  this  option  is  used  several times, only the first one is
              used.

              See also  --proxy-ntlm.  --ntlm  requires  that  the  underlying
              libcurl  was built to support TLS. This option overrides --basic
              and --negotiate and --digest and --anyauth.

       --oauth2-bearer <token>
              (IMAP POP3 SMTP HTTP) Specify the Bearer  Token  for  OAUTH  2.0
              server  authentication.  The Bearer Token is used in conjunction
              with the user name which can be specified as part of  the  --url
              or -u, --user options.

              The  Bearer  Token  and user name are formatted according to RFC
              6750.

              If this option is used several times, the last one will be used.

       -o, --output <file>
              Write output to <file> instead of stdout. If you are using {} or
              [] to fetch multiple documents, you should quote the URL and you
              can use '#' followed by a number in the <file>  specifier.  That
              variable  will  be  replaced with the current string for the URL
              being fetched. Like in:

               curl "http://{one,two}.example.com" -o "file_#1.txt"

              or use several variables like:

               curl "http://{site,host}.host[1-5].com" -o "#1_#2"

              You may use this option as many times as the number of URLs  you
              have.  For  example, if you specify two URLs on the same command
              line, you can use it like this:

                curl -o aa example.com -o bb example.net

              and the order of the -o options and  the  URLs  doesn't  matter,
              just  that  the  first -o is for the first URL and so on, so the
              above command line can also be written as

                curl example.com example.net -o aa -o bb

              See also the --create-dirs option to create the  local  directo-
              ries  dynamically.  Specifying the output as '-' (a single dash)
              will force the output to be done to stdout.

              See also -O, --remote-name and --remote-name-all and  -J,  --re-
              mote-header-name.

       --parallel-immediate
              When  doing  parallel  transfers, this option will instruct curl
              that it should rather prefer opening up more connections in par-
              allel at once rather than waiting to see if new transfers can be
              added as multiplexed streams on another connection.

              See also -Z, --parallel and --parallel-max. Added in 7.68.0.

       --parallel-max
              When asked to do parallel transfers, using -Z, --parallel,  this
              option controls the maximum amount of transfers to do simultane-
              ously.

              The default is 50.

              See also -Z, --parallel. Added in 7.66.0.

       -Z, --parallel
              Makes curl perform its transfers in parallel as compared to  the
              regular serial manner.

              Added in 7.66.0.

       --pass <phrase>
              (SSH TLS) Passphrase for the private key

              If this option is used several times, the last one will be used.

       --path-as-is
              Tell  curl  to  not handle sequences of /../ or /./ in the given
              URL path. Normally curl will squash or merge them  according  to
              standards but with this option set you tell it not to do that.

              Added in 7.42.0.

       --pinnedpubkey <hashes>
              (TLS)  Tells  curl  to  use  the  specified  public key file (or
              hashes) to verify the peer. This can be a path to a  file  which
              contains a single public key in PEM or DER format, or any number
              of base64 encoded sha256 hashes preceded by 'sha256//' and sepa-
              rated by ';'

              When  negotiating  a  TLS  or SSL connection, the server sends a
              certificate indicating its identity. A public key  is  extracted
              from  this certificate and if it does not exactly match the pub-
              lic key provided to this option, curl will abort the  connection
              before sending or receiving any data.

              PEM/DER support:
                7.39.0: OpenSSL, GnuTLS and GSKit
                7.43.0: NSS and wolfSSL
                7.47.0: mbedtls sha256 support:
                7.44.0: OpenSSL, GnuTLS, NSS and wolfSSL
                7.47.0: mbedtls Other SSL backends not supported.

              If this option is used several times, the last one will be used.

       --post301
              (HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert POST
              requests into GET requests when following a 301 redirection. The
              non-RFC  behaviour  is  ubiquitous in web browsers, so curl does
              the conversion by default to maintain  consistency.  However,  a
              server  may  require  a POST to remain a POST after such a redi-
              rection. This option is meaningful only when using  -L,  --loca-
              tion.

              See  also  --post302  and --post303 and -L, --location. Added in
              7.17.1.

       --post302
              (HTTP) Tells curl to respect RFC 7231/6.4.3 and not convert POST
              requests into GET requests when following a 302 redirection. The
              non-RFC behaviour is ubiquitous in web browsers,  so  curl  does
              the  conversion  by  default to maintain consistency. However, a
              server may require a POST to remain a POST after  such  a  redi-
              rection.  This  option is meaningful only when using -L, --loca-
              tion.

              See also --post301 and --post303 and -L,  --location.  Added  in
              7.19.1.

       --post303
              (HTTP) Tells curl to violate RFC 7231/6.4.4 and not convert POST
              requests into GET requests when following  303  redirections.  A
              server may require a POST to remain a POST after a 303 redirect-
              ion. This option is meaningful only when using -L, --location.

              See also --post302 and --post301 and -L,  --location.  Added  in
              7.26.0.

       --preproxy [protocol://]host[:port]
              Use  the  specified  SOCKS proxy before connecting to an HTTP or
              HTTPS -x, --proxy. In such a case curl  first  connects  to  the
              SOCKS  proxy  and  then  connects (through SOCKS) to the HTTP or
              HTTPS proxy. Hence pre proxy.

              The pre proxy string should be specified with a protocol:// pre-
              fix  to  specify  alternative  proxy  protocols.  Use socks4://,
              socks4a://, socks5:// or  socks5h://  to  request  the  specific
              SOCKS  version  to be used. No protocol specified will make curl
              default to SOCKS4.

              If the port number is not specified in the proxy string,  it  is
              assumed to be 1080.

              User and password that might be provided in the proxy string are
              URL decoded by curl. This allows you to pass in special  charac-
              ters such as @ by using %40 or pass in a colon with %3a.

              If this option is used several times, the last one will be used.

              Added in 7.52.0.

       -#, --progress-bar
              Make curl display transfer progress as a simple progress bar in-
              stead of the standard, more informational, meter.

              This progress bar draws a single line of '#'  characters  across
              the screen and shows a percentage if the transfer size is known.
              For transfers without a known size, there  will  be  space  ship
              (-=o=-)  that  moves back and forth but only while data is being
              transferred, with a set of flying hash sign symbols on top.

       --proto-default <protocol>
              Tells curl to use protocol for any URL missing a scheme name.

              Example:

               curl --proto-default https ftp.mozilla.org

              An unknown or unsupported  protocol  causes  error  CURLE_UNSUP-
              PORTED_PROTOCOL (1).

              This option does not change the default proxy protocol (http).

              Without  this  option curl would make a guess based on the host,
              see --url for details.

              Added in 7.45.0.

       --proto-redir <protocols>
              Tells curl to limit what protocols it may use on redirect.  Pro-
              tocols  denied by --proto are not overridden by this option. See
              --proto for how protocols are represented.

              Example, allow only HTTP and HTTPS on redirect:

               curl --proto-redir -all,http,https http://example.com

              By default curl will allow HTTP, HTTPS, FTP and FTPS on redirect
              (7.65.2).  Older versions of curl allowed all protocols on redi-
              rect except several disabled for security reasons: Since  7.19.4
              FILE  and  SCP  are  disabled, and since 7.40.0 SMB and SMBS are
              also disabled. Specifying all or +all enables all  protocols  on
              redirect, including those disabled for security.

              Added in 7.20.2.

       --proto <protocols>
              Tells  curl  to limit what protocols it may use in the transfer.
              Protocols are evaluated left to right, are comma separated,  and
              are  each  a protocol name or 'all', optionally prefixed by zero
              or more modifiers. Available modifiers are:

              +  Permit this protocol in addition to protocols already permit-
                 ted (this is the default if no modifier is used).

              -  Deny  this  protocol,  removing it from the list of protocols
                 already permitted.

              =  Permit only this protocol (ignoring the list already  permit-
                 ted),  though subject to later modification by subsequent en-
                 tries in the comma separated list.

              For example:

              --proto -ftps  uses the default protocols, but disables ftps

              --proto -all,https,+http
                             only enables http and https

              --proto =http,https
                             also only enables http and https

       Unknown protocols produce a warning. This allows scripts to safely rely
       on being able to disable potentially dangerous protocols, without rely-
       ing upon support for that protocol being built into curl  to  avoid  an
       error.

       This option can be used multiple times, in which case the effect is the
       same as concatenating the protocols into one instance of the option.

       See also --proto-redir and --proto-default. Added in 7.20.2.

       --proxy-anyauth
              Tells curl to pick a suitable authentication method when  commu-
              nicating  with  the  given HTTP proxy. This might cause an extra
              request/response round-trip.

              See also -x, --proxy and --proxy-basic and --proxy-digest. Added
              in 7.13.2.

       --proxy-basic
              Tells  curl  to use HTTP Basic authentication when communicating
              with the given proxy. Use --basic for enabling HTTP Basic with a
              remote  host.  Basic  is  the default authentication method curl
              uses with proxies.

              See also -x, --proxy and --proxy-anyauth and --proxy-digest.

       --proxy-cacert <file>
              Same as --cacert but used in HTTPS proxy context.

              See also  --proxy-capath  and  --cacert  and  --capath  and  -x,
              --proxy. Added in 7.52.0.

       --proxy-capath <dir>
              Same as --capath but used in HTTPS proxy context.

              See  also  --proxy-cacert and -x, --proxy and --capath. Added in
              7.52.0.

       --proxy-cert-type <type>
              Same as --cert-type but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-cert <cert[:passwd]>
              Same as -E, --cert but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-ciphers <list>
              Same as --ciphers but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-crlfile <file>
              Same as --crlfile but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-digest
              Tells curl to use HTTP Digest authentication when  communicating
              with the given proxy. Use --digest for enabling HTTP Digest with
              a remote host.

              See also -x, --proxy and --proxy-anyauth and --proxy-basic.

       --proxy-header <header/@file>
              (HTTP) Extra header to include in the request when sending  HTTP
              to a proxy. You may specify any number of extra headers. This is
              the equivalent option to -H, --header but is for proxy  communi-
              cation  only  like  in CONNECT requests when you want a separate
              header sent to the proxy to what is sent to  the  actual  remote
              host.

              curl  will  make  sure  that each header you add/replace is sent
              with the proper end-of-line marker, you should thus not add that
              as a part of the header content: do not add newlines or carriage
              returns, they will only mess things up for you.

              Headers specified with this option will not be included  in  re-
              quests that curl knows will not be sent to a proxy.

              Starting  in  7.55.0, this option can take an argument in @file-
              name style, which then adds a header for each line in the  input
              file. Using @- will make curl read the header file from stdin.

              This  option  can  be  used multiple times to add/replace/remove
              multiple headers.

              Added in 7.37.0.
       --proxy-insecure
              Same as -k, --insecure but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-key-type <type>
              Same as --key-type but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-key <key>
              Same as --key but used in HTTPS proxy context.

       --proxy-negotiate
              Tells curl to use HTTP Negotiate  (SPNEGO)  authentication  when
              communicating with the given proxy. Use --negotiate for enabling
              HTTP Negotiate (SPNEGO) with a remote host.

              See also --proxy-anyauth and --proxy-basic. Added in 7.17.1.

       --proxy-ntlm
              Tells curl to use HTTP NTLM  authentication  when  communicating
              with the given proxy. Use --ntlm for enabling NTLM with a remote
              host.

              See also --proxy-negotiate and --proxy-anyauth.

       --proxy-pass <phrase>
              Same as --pass but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-pinnedpubkey <hashes>
              (TLS) Tells curl to  use  the  specified  public  key  file  (or
              hashes)  to verify the proxy. This can be a path to a file which
              contains a single public key in PEM or DER format, or any number
              of base64 encoded sha256 hashes preceded by 'sha256//' and sepa-
              rated by ';'

              When negotiating a TLS or SSL connection,  the  server  sends  a
              certificate  indicating  its identity. A public key is extracted
              from this certificate and if it does not exactly match the  pub-
              lic  key provided to this option, curl will abort the connection
              before sending or receiving any data.

              If this option is used several times, the last one will be used.

       --proxy-service-name <name>
              This option allows you to change the service name for proxy  ne-
              gotiation.

              Added in 7.43.0.

       --proxy-ssl-allow-beast
              Same as --ssl-allow-beast but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tls13-ciphers <ciphersuite list>
              (TLS)  Specifies which cipher suites to use in the connection to
              your HTTPS proxy when it negotiates TLS 1.3. The list of ciphers
              suites  must  specify  valid  ciphers. Read up on TLS 1.3 cipher
              suite details on this URL:

               https://curl.haxx.se/docs/ssl-ciphers.html

              This option is currently used only when curl  is  built  to  use
              OpenSSL 1.1.1 or later. If you are using a different SSL backend
              you can try setting TLS 1.3 cipher suites by using the  --proxy-
              ciphers option.

              If this option is used several times, the last one will be used.

       --proxy-tlsauthtype <type>
              Same as --tlsauthtype but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlspassword <string>
              Same as --tlspassword but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsuser <name>
              Same as --tlsuser but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsv1
              Same as -1, --tlsv1 but used in HTTPS proxy context.

              Added in 7.52.0.

       -U, --proxy-user <user:password>
              Specify  the user name and password to use for proxy authentica-
              tion.

              If you use a Windows SSPI-enabled curl binary and do either  Ne-
              gotiate  or NTLM authentication then you can tell curl to select
              the user name and password from your environment by specifying a
              single colon with this option: "-U :".

              On systems where it works, curl will hide the given option argu-
              ment from process listings. This is not enough to  protect  cre-
              dentials  from  possibly getting seen by other users on the same
              system as they will still be visible for a brief  moment  before
              cleared. Such sensitive data should be retrieved from a file in-
              stead or similar and never used in clear text in a command line.
              If this option is used several times, the last one will be used.

       -x, --proxy [protocol://]host[:port]
              Use the specified proxy.

              The proxy string can be specified with a protocol:// prefix.  No
              protocol specified or http:// will be treated as HTTP proxy. Use
              socks4://, socks4a://, socks5:// or socks5h:// to request a spe-
              cific SOCKS version to be used.  (The protocol support was added
              in curl 7.21.7)

              HTTPS proxy support via https:// protocol prefix  was  added  in
              7.52.0 for OpenSSL, GnuTLS and NSS.

              Unrecognized  and  unsupported  proxy  protocols  cause an error
              since 7.52.0.  Prior versions may ignore the  protocol  and  use
              http:// instead.

              If  the  port number is not specified in the proxy string, it is
              assumed to be 1080.

              This option overrides existing environment  variables  that  set
              the  proxy  to use. If there's an environment variable setting a
              proxy, you can set proxy to "" to override it.

              All operations that are performed over an HTTP proxy will trans-
              parently  be  converted  to HTTP. It means that certain protocol
              specific operations might not be available. This is not the case
              if you can tunnel through the proxy, as one with the -p, --prox-
              ytunnel option.

              User and password that might be provided in the proxy string are
              URL  decoded by curl. This allows you to pass in special charac-
              ters such as @ by using %40 or pass in a colon with %3a.

              The proxy host can be specified the exact same way as the  proxy
              environment  variables,  including the protocol prefix (http://)
              and the embedded user + password.

              If this option is used several times, the last one will be used.

       --proxy1.0 <host[:port]>
              Use the specified HTTP 1.0 proxy. If  the  port  number  is  not
              specified, it is assumed at port 1080.

              The  only  difference between this and the HTTP proxy option -x,
              --proxy, is that attempts to use CONNECT through the proxy  will
              specify an HTTP 1.0 protocol instead of the default HTTP 1.1.

       -p, --proxytunnel
              When  an  HTTP  proxy is used -x, --proxy, this option will make
              curl tunnel through the proxy. The tunnel approach is made  with
              the  HTTP  proxy CONNECT request and requires that the proxy al-
              lows direct connect to the remote port number curl wants to tun-
              nel through to.

              To  suppress  proxy CONNECT response headers when curl is set to
              output headers use --suppress-connect-headers.

              See also -x, --proxy.

       --pubkey <key>
              (SFTP SCP) Public key file name. Allows you to provide your pub-
              lic key in this separate file.

              If this option is used several times, the last one will be used.
              (As of 7.39.0, curl attempts to automatically extract the public
              key from the private key file, so passing this option is  gener-
              ally not required. Note that this public key extraction requires
              libcurl to be linked against a copy of libssh2 1.2.8  or  higher
              that is itself linked against OpenSSL.)

       -Q, --quote
              (FTP  SFTP)  Send an arbitrary command to the remote FTP or SFTP
              server. Quote commands are sent BEFORE the transfer takes  place
              (just  after  the  initial PWD command in an FTP transfer, to be
              exact). To make commands take place after a successful transfer,
              prefix  them  with  a  dash '-'.  To make commands be sent after
              curl has changed the working directory, just before the transfer
              command(s),  prefix  the  command  with a '+' (this is only sup-
              ported for FTP). You may specify any number of commands.

              If the server returns failure for one of the commands,  the  en-
              tire operation will be aborted. You must send syntactically cor-
              rect FTP commands as RFC 959 defines to FTP servers, or  one  of
              the commands listed below to SFTP servers.

              Prefix  the  command  with an asterisk (*) to make curl continue
              even if the command fails as by default curl will stop at  first
              failure.

              This option can be used multiple times.

              SFTP  is a binary protocol. Unlike for FTP, curl interprets SFTP
              quote commands itself before sending them to the  server.   File
              names may be quoted shell-style to embed spaces or special char-
              acters.  Following is the list of all supported SFTP quote  com-
              mands:

              chgrp group file
                     The  chgrp command sets the group ID of the file named by
                     the file operand to the group ID specified by  the  group
                     operand. The group operand is a decimal integer group ID.

              chmod mode file
                     The  chmod  command  modifies  the  file mode bits of the
                     specified file. The mode operand is an octal integer mode
                     number.

              chown user file
                     The chown command sets the owner of the file named by the
                     file operand to the user ID specified by the  user  oper-
                     and. The user operand is a decimal integer user ID.

              ln source_file target_file
                     The ln and symlink commands create a symbolic link at the
                     target_file location pointing to  the  source_file  loca-
                     tion.

              mkdir directory_name
                     The  mkdir command creates the directory named by the di-
                     rectory_name operand.

              pwd    The pwd command returns the absolute pathname of the cur-
                     rent working directory.

              rename source target
                     The rename command renames the file or directory named by
                     the source operand to the destination path named  by  the
                     target operand.

              rm file
                     The rm command removes the file specified by the file op-
                     erand.

              rmdir directory
                     The rmdir command removes the directory  entry  specified
                     by the directory operand, provided it is empty.

              symlink source_file target_file
                     See ln.

       --random-file <file>
              Specify the path name to file containing what will be considered
              as random data. The data may be used to seed the  random  engine
              for SSL connections.  See also the --egd-file option.

       -r, --range <range>
              (HTTP FTP SFTP FILE) Retrieve a byte range (i.e. a partial docu-
              ment) from an HTTP/1.1, FTP or SFTP  server  or  a  local  FILE.
              Ranges can be specified in a number of ways.

              0-499     specifies the first 500 bytes

              500-999   specifies the second 500 bytes

              -500      specifies the last 500 bytes

              9500-     specifies the bytes from offset 9500 and forward

              0-0,-1    specifies the first and last byte only(*)(HTTP)

              100-199,500-599
                        specifies two separate 100-byte ranges(*) (HTTP)

              (*)  = NOTE that this will cause the server to reply with a mul-
              tipart response!

              Only digit characters (0-9) are valid in the 'start' and  'stop'
              fields  of the 'start-stop' range syntax. If a non-digit charac-
              ter is given in the range, the server's response will be unspec-
              ified, depending on the server's configuration.

              You  should also be aware that many HTTP/1.1 servers do not have
              this feature enabled, so that when you attempt to get  a  range,
              you'll instead get the whole document.

              FTP  and  SFTP  range  downloads only support the simple 'start-
              stop' syntax (optionally with one of the numbers  omitted).  FTP
              use depends on the extended FTP command SIZE.

              If this option is used several times, the last one will be used.

       --raw  (HTTP) When used, it disables all internal HTTP decoding of con-
              tent or transfer encodings and instead makes them passed on  un-
              altered, raw.

              Added in 7.16.2.

       -e, --referer <URL>
              (HTTP) Sends the "Referrer Page" information to the HTTP server.
              This can also be set with the -H, --header flag of course.  When
              used  with  -L,  --location  you  can  append ";auto" to the -e,
              --referer URL to make curl automatically set  the  previous  URL
              when  it  follows  a Location: header. The ";auto" string can be
              used alone, even if you don't set an initial -e, --referer.

              If this option is used several times, the last one will be used.

              See also -A, --user-agent and -H, --header.

       -J, --remote-header-name
              (HTTP) This option tells the -O, --remote-name option to use the
              server-specified  Content-Disposition  filename  instead  of ex-
              tracting a filename from the URL.

              If the server specifies a file name and a file  with  that  name
              already  exists  in the current working directory it will not be
              overwritten and an error will occur. If the server doesn't spec-
              ify a file name then this option has no effect.

              There's  no  attempt to decode %-sequences (yet) in the provided
              file name, so this option may provide you with rather unexpected
              file names.

              WARNING:  Exercise  judicious  use of this option, especially on
              Windows. A rogue server could send you the  name  of  a  DLL  or
              other  file  that could possibly be loaded automatically by Win-
              dows or some third party software.

       --remote-name-all
              This option changes the default action for all given URLs to  be
              dealt with as if -O, --remote-name were used for each one. So if
              you want to disable that for a specific URL after --remote-name-
              all has been used, you must use "-o -" or --no-remote-name.

              Added in 7.19.0.

       -O, --remote-name
              Write  output to a local file named like the remote file we get.
              (Only the file part of the remote file is used, the path is  cut
              off.)

              The  file will be saved in the current working directory. If you
              want the file saved in a  different  directory,  make  sure  you
              change  the  current working directory before invoking curl with
              this option.

              The remote file name to use for saving  is  extracted  from  the
              given  URL,  nothing  else,  and if it already exists it will be
              overwritten. If you want the server to be  able  to  choose  the
              file name refer to -J, --remote-header-name which can be used in
              addition to this option. If the server chooses a file  name  and
              that name already exists it will not be overwritten.

              There is no URL decoding done on the file name. If it has %20 or
              other URL encoded parts of the name, they will end up  as-is  as
              file name.

              You  may use this option as many times as the number of URLs you
              have.

       -R, --remote-time
              When used, this will make curl attempt to figure out  the  time-
              stamp  of the remote file, and if that is available make the lo-
              cal file get that same timestamp.

       --request-target
              (HTTP) Tells curl to use an alternative "target" (path)  instead
              of  using  the  path as provided in the URL. Particularly useful
              when wanting to issue HTTP requests  without  leading  slash  or
              other  data  that  doesn't  follow the regular URL pattern, like
              "OPTIONS *".

              Added in 7.55.0.

       -X, --request <command>
              (HTTP) Specifies a custom request method to use when communicat-
              ing  with the HTTP server.  The specified request method will be
              used instead of the method otherwise  used  (which  defaults  to
              GET).  Read  the HTTP 1.1 specification for details and explana-
              tions. Common additional HTTP requests include PUT  and  DELETE,
              but related technologies like WebDAV offers PROPFIND, COPY, MOVE
              and more.

              Normally you don't need this option. All  sorts  of  GET,  HEAD,
              POST and PUT requests are rather invoked by using dedicated com-
              mand line options.

              This option only changes the actual word used in  the  HTTP  re-
              quest, it does not alter the way curl behaves. So for example if
              you want to make a proper HEAD request, using -X HEAD  will  not
              suffice. You need to use the -I, --head option.

              The  method  string  you set with -X, --request will be used for
              all requests, which if you for example use  -L,  --location  may
              cause  unintended  side-effects when curl doesn't change request
              method according to the HTTP 30x response codes - and similar.

              (FTP) Specifies a custom FTP command to use instead of LIST when
              doing file lists with FTP.

              (POP3) Specifies a custom POP3 command to use instead of LIST or
              RETR. (Added in 7.26.0)

              (IMAP) Specifies a custom IMAP command to use instead  of  LIST.
              (Added in 7.30.0)

              (SMTP) Specifies a custom SMTP command to use instead of HELP or
              VRFY. (Added in 7.34.0)

              If this option is used several times, the last one will be used.

       --resolve <host:port:addr[,addr]...>
              Provide a custom address for a specific host and port pair.  Us-
              ing  this, you can make the curl requests(s) use a specified ad-
              dress and prevent the otherwise normally resolved address to  be
              used.  Consider  it a sort of /etc/hosts alternative provided on
              the command line. The port number should be the number used  for
              the  specific  protocol  the host will be used for. It means you
              need several entries if you want to provide address for the same
              host but different ports.

              By  specifying '*' as host you can tell curl to resolve any host
              and specific port pair to the specified address. Wildcard is re-
              solved  last so any --resolve with a specific host and port will
              be used first.

              The provided address set by this option will be used even if -4,
              --ipv4 or -6, --ipv6 is set to make curl use another IP version.
              Support for providing the IP address within [brackets] was added
              in 7.57.0.

              Support for providing multiple IP addresses per entry was  added
              in 7.59.0.

              Support for resolving with wildcard was added in 7.64.0.

              This option can be used many times to add many host names to re-
              solve.

              Added in 7.21.3.

       --retry-all-errors
              Retry on any error. This option is used together with --retry.

              This option is the "sledgehammer" of retrying. Do not  use  this
              option by default (eg in curlrc), there may be unintended conse-
              quences such as sending or receiving duplicate data. Do not  use
              with  redirected  input or output. You'd be much better off han-
              dling your unique problems in shell script. Please read the  ex-
              ample below.

              Warning:  For server compatibility curl attempts to retry failed
              flaky transfers as close as possible to how they  were  started,
              but  this  is  not possible with redirected input or output. For
              example, before retrying it removes output data  from  a  failed
              partial  transfer  that  was  written to an output file. However
              this is not true of data redirected to a | pipe or > file, which
              are  not reset. We strongly suggest don't parse or record output
              via redirect in combination with this option, since you may  re-
              ceive duplicate data.

              Added in 7.71.0.

       --retry-connrefused
              In  addition to the other conditions, consider ECONNREFUSED as a
              transient error too for --retry. This option  is  used  together
              with --retry.

              Added in 7.52.0.

       --retry-delay <seconds>
              Make  curl  sleep  this  amount of time before each retry when a
              transfer has failed with a transient error (it changes  the  de-
              fault  backoff  time  algorithm between retries). This option is
              only interesting if --retry is also used. Setting this delay  to
              zero will make curl use the default backoff time.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --retry-max-time <seconds>
              The  retry timer is reset before the first transfer attempt. Re-
              tries will be done as usual (see --retry) as long as  the  timer
              hasn't reached this given limit. Notice that if the timer hasn't
              reached the limit, the request will be made and  while  perform-
              ing,  it may take longer than this given time period. To limit a
              single request's maximum time, use -m, --max-time.  Set this op-
              tion to zero to not timeout retries.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --retry <num>
              If  a  transient  error is returned when curl tries to perform a
              transfer, it will retry this number of times before  giving  up.
              Setting  the  number to 0 makes curl do no retries (which is the
              default). Transient error means either: a timeout,  an  FTP  4xx
              response code or an HTTP 408 or 5xx response code.

              When  curl  is about to retry a transfer, it will first wait one
              second and then for all forthcoming retries it will  double  the
              waiting  time until it reaches 10 minutes which then will be the
              delay between the rest of the retries.  By  using  --retry-delay
              you   disable  this  exponential  backoff  algorithm.  See  also
              --retry-max-time to limit the total time allowed for retries.

              Since curl 7.66.0, curl will comply with  the  Retry-After:  re-
              sponse  header if one was present to know when to issue the next
              retry.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --sasl-authzid <identity>
              Use this authorisation identity (authzid), during SASL PLAIN au-
              thentication,  in addition to the authentication identity (auth-
              cid) as specified by -u, --user.

              If the option isn't specified, the server will  derive  the  au-
              thzid  from  the authcid, but if specified, and depending on the
              server implementation, it may be used to access  another  user's
              inbox,  that  the  user  has been granted access to, or a shared
              mailbox for example.

              Added in 7.66.0.

       --sasl-ir
              Enable initial response in SASL authentication.

              Added in 7.31.0.

       --service-name <name>
              This option allows you to change the service name for SPNEGO.

              Examples:   --negotiate   --service-name   sockd    would    use
              sockd/server-name.

              Added in 7.43.0.
       -S, --show-error
              When used with -s, --silent, it makes curl show an error message
              if it fails.
       -s, --silent
              Silent or quiet mode. Don't show progress meter  or  error  mes-
              sages.   Makes  Curl mute. It will still output the data you ask
              for, potentially even to the terminal/stdout unless you redirect
              it.

              Use  -S,  --show-error  in  addition  to  this option to disable
              progress meter but still show error messages.

              See also -v, --verbose and --stderr.

       --socks4 <host[:port]>
              Use the specified SOCKS4 proxy. If the port number is not speci-
              fied, it is assumed at port 1080.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              Since 7.21.7, this option is superfluous since you can specify a
              socks4 proxy with -x, --proxy using a socks4:// protocol prefix.
              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the same time -x, --proxy is used with an HTTP/HTTPS  proxy.  In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Added in 7.15.2.

       --socks4a <host[:port]>
              Use the specified SOCKS4a proxy. If the port number is not spec-
              ified, it is assumed at port 1080.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              Since 7.21.7, this option is superfluous since you can specify a
              socks4a  proxy with -x, --proxy using a socks4a:// protocol pre-
              fix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the  same  time -x, --proxy is used with an HTTP/HTTPS proxy. In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Added in 7.18.0.

       --socks5-basic
              Tells curl to use username/password authentication when connect-
              ing to a SOCKS5 proxy.  The username/password authentication  is
              enabled  by  default.   Use --socks5-gssapi to force GSS-API au-
              thentication to SOCKS5 proxies.

              Added in 7.55.0.

       --socks5-gssapi-nec
              As part of the GSS-API negotiation a protection mode is  negoti-
              ated.  RFC  1961 says in section 4.3/4.4 it should be protected,
              but the NEC  reference  implementation  does  not.   The  option
              --socks5-gssapi-nec  allows the unprotected exchange of the pro-
              tection mode negotiation.

              Added in 7.19.4.

       --socks5-gssapi-service <name>
              The default service name for a socks server is rcmd/server-fqdn.
              This option allows you to change it.

              Examples:   --socks5  proxy-name  --socks5-gssapi-service  sockd
              would use sockd/proxy-name --socks5 proxy-name  --socks5-gssapi-
              service  sockd/real-name  would  use  sockd/real-name  for cases
              where the proxy-name does not match the principal name.

              Added in 7.19.4.

       --socks5-gssapi
              Tells curl to use GSS-API authentication when  connecting  to  a
              SOCKS5  proxy.  The GSS-API authentication is enabled by default
              (if curl is compiled with GSS-API support).  Use  --socks5-basic
              to force username/password authentication to SOCKS5 proxies.

              Added in 7.55.0.

       --socks5-hostname <host[:port]>
              Use  the  specified  SOCKS5 proxy (and let the proxy resolve the
              host name). If the port number is not specified, it  is  assumed
              at port 1080.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              Since 7.21.7, this option is superfluous since you can specify a
              socks5 hostname proxy with -x, --proxy using a socks5h:// proto-
              col prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the  same  time -x, --proxy is used with an HTTP/HTTPS proxy. In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Added in 7.18.0.

       --socks5 <host[:port]>
              Use  the  specified SOCKS5 proxy - but resolve the host name lo-
              cally. If the port number is not specified,  it  is  assumed  at
              port 1080.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              Since 7.21.7, this option is superfluous since you can specify a
              socks5 proxy with -x, --proxy using a socks5:// protocol prefix.
              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the same time -x, --proxy is used with an HTTP/HTTPS  proxy.  In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.
              This option (as well as --socks4) does not work with IPV6,  FTPS
              or LDAP.

              Added in 7.18.0.

       -Y, --speed-limit <speed>
              If a download is slower than this given speed (in bytes per sec-
              ond) for speed-time seconds it gets aborted. speed-time  is  set
              with -y, --speed-time and is 30 if not set.

              If this option is used several times, the last one will be used.

       -y, --speed-time <seconds>
              If a download is slower than speed-limit bytes per second during
              a speed-time period, the download gets aborted. If speed-time is
              used,  the  default  speed-limit  will  be 1 unless set with -Y,
              --speed-limit.

              This option controls transfers and thus  will  not  affect  slow
              connects  etc.  If this is a concern for you, try the --connect-
              timeout option.

              If this option is used several times, the last one will be used.

       --ssl-allow-beast
              This option tells curl to not work around a security flaw in the
              SSL3  and TLS1.0 protocols known as BEAST.  If this option isn't
              used, the SSL layer may use workarounds known to cause  interop-
              erability problems with some older SSL implementations. WARNING:
              this option loosens the SSL security, and by using this flag you
              ask for exactly that.

              Added in 7.25.0.

       --ssl-no-revoke
              (Schannel) This option tells curl to disable certificate revoca-
              tion checks.  WARNING: this option loosens the SSL security, and
              by using this flag you ask for exactly that.

              Added in 7.44.0.

       --ssl-reqd
              (FTP IMAP POP3 SMTP) Require SSL/TLS for the connection.  Termi-
              nates the connection if the server doesn't support SSL/TLS.

              This option was formerly known as --ftp-ssl-reqd.

              Added in 7.20.0.

       --ssl-revoke-best-effort
              (Schannel) This option tells curl to ignore certificate  revoca-
              tion checks when they failed due to missing/offline distribution
              points for the revocation check lists.

              Added in 7.70.0.

       --ssl  (FTP IMAP POP3 SMTP) Try to use SSL/TLS for the connection.  Re-
              verts  to  a non-secure connection if the server doesn't support
              SSL/TLS.  See also --ftp-ssl-control and --ssl-reqd for  differ-
              ent levels of encryption required.

              This  option  was formerly known as --ftp-ssl (Added in 7.11.0).
              That option name can still be used but will be removed in a  fu-
              ture version.

              Added in 7.20.0.

       -2, --sslv2
              (SSL)  Forces  curl to use SSL version 2 when negotiating with a
              remote SSL server. Sometimes curl is built  without  SSLv2  sup-
              port. SSLv2 is widely considered insecure (see RFC 6176).

              See  also  --http1.1  and --http2. -2, --sslv2 requires that the
              underlying libcurl was built to support TLS. This  option  over-
              rides -3, --sslv3 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       -3, --sslv3
              (SSL)  Forces  curl to use SSL version 3 when negotiating with a
              remote SSL server. Sometimes curl is built  without  SSLv3  sup-
              port. SSLv3 is widely considered insecure (see RFC 7568).

              See  also  --http1.1  and --http2. -3, --sslv3 requires that the
              underlying libcurl was built to support TLS. This  option  over-
              rides -2, --sslv2 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       --stderr
              Redirect  all writes to stderr to the specified file instead. If
              the file name is a plain '-', it is instead written to stdout.

              If this option is used several times, the last one will be used.

              See also -v, --verbose and -s, --silent.

       --styled-output
              Enables the automatic use of bold font styles when writing  HTTP
              headers  to  the terminal. Use --no-styled-output to switch them
              off.

              Added in 7.61.0.

       --suppress-connect-headers
              When -p, --proxytunnel is used and a  CONNECT  request  is  made
              don't  output  proxy  CONNECT  response  headers. This option is
              meant to be used with -D, --dump-header or -i,  --include  which
              are  used  to show protocol headers in the output. It has no ef-
              fect on debug options such as -v, --verbose or --trace,  or  any
              statistics.

              See also -D, --dump-header and -i, --include and -p, --proxytun-
              nel.

       --tcp-fastopen
              Enable use of TCP Fast Open (RFC7413).

              Added in 7.49.0.

       --tcp-nodelay
              Turn on the TCP_NODELAY option. See the curl_easy_setopt(3)  man
              page for details about this option.

              Since  7.50.2,  curl sets this option by default and you need to
              explicitly switch it off if you don't want it on.

              Added in 7.11.2.

       -t, --telnet-option <opt=val>
              Pass options to the telnet protocol. Supported options are:

              TTYPE=<term> Sets the terminal type.

              XDISPLOC=<X display> Sets the X display location.

              NEW_ENV=<var,val> Sets an environment variable.

       --tftp-blksize <value>
              (TFTP) Set TFTP BLKSIZE option (must be >512). This is the block
              size that curl will try to use when transferring data to or from
              a TFTP server. By default 512 bytes will be used.

              If this option is used several times, the last one will be used.

              Added in 7.20.0.

       --tftp-no-options
              (TFTP) Tells curl not to send TFTP options requests.

              This option improves interop with some legacy  servers  that  do
              not  acknowledge  or  properly implement TFTP options. When this
              option is used --tftp-blksize is ignored.

              Added in 7.48.0.

       -z, --time-cond <time>
              (HTTP FTP) Request a file that has been modified later than  the
              given  time  and date, or one that has been modified before that
              time. The <date expression> can be all sorts of date strings  or
              if it doesn't match any internal ones, it is taken as a filename
              and tries to get the modification date (mtime) from  <file>  in-
              stead. See the curl_getdate(3) man pages for date expression de-
              tails.

              Start the date expression with a dash (-) to make it request for
              a  document that is older than the given date/time, default is a
              document that is newer than the specified date/time.

              If this option is used several times, the last one will be used.

       --tls-max <VERSION>
              (SSL) VERSION defines maximum supported TLS version. The minimum
              acceptable  version  is  set  by  tlsv1.0,  tlsv1.1,  tlsv1.2 or
              tlsv1.3.

              If the connection is done without TLS, this option  has  no  ef-
              fect. This includes QUIC-using (HTTP/3) transfers.

              default
                     Use up to recommended TLS version.

              1.0    Use up to TLSv1.0.
              1.1    Use up to TLSv1.1.
              1.2    Use up to TLSv1.2.
              1.3    Use up to TLSv1.3.

       See also --tlsv1.0 and --tlsv1.1 and --tlsv1.2 and --tlsv1.3. --tls-max
       requires that the underlying libcurl was built to support TLS. Added in
       7.54.0.

       --tls13-ciphers <ciphersuite list>
              (TLS)  Specifies which cipher suites to use in the connection if
              it negotiates TLS 1.3. The list of ciphers suites  must  specify
              valid  ciphers.  Read up on TLS 1.3 cipher suite details on this
              URL:

               https://curl.haxx.se/docs/ssl-ciphers.html

              This option is currently used only when curl  is  built  to  use
              OpenSSL 1.1.1 or later. If you are using a different SSL backend
              you can try setting TLS 1.3 cipher suites by using the --ciphers
              option.

              If this option is used several times, the last one will be used.

       --tlsauthtype <type>
              Set  TLS  authentication type. Currently, the only supported op-
              tion  is  "SRP",  for  TLS-SRP  (RFC  5054).  If  --tlsuser  and
              --tlspassword  are specified but --tlsauthtype is not, then this
              option defaults to "SRP".  This option works only if the  under-
              lying  libcurl  is  built  with  TLS-SRP support, which requires
              OpenSSL or GnuTLS with TLS-SRP support.

              Added in 7.21.4.

       --tlspassword
              Set password for use with the TLS authentication  method  speci-
              fied with --tlsauthtype. Requires that --tlsuser also be set.

              This doesn't work with TLS 1.3.

              Added in 7.21.4.
       --tlsuser <name>
              Set  username  for use with the TLS authentication method speci-
              fied with --tlsauthtype. Requires  that  --tlspassword  also  is
              set.

              This doesn't work with TLS 1.3.

              Added in 7.21.4.

       --tlsv1.0
              (TLS)  Forces curl to use TLS version 1.0 or later when connect-
              ing to a remote TLS server.

              In old versions of curl this  option  was  documented  to  allow
              _only_  TLS  1.0, but behavior was inconsistent depending on the
              TLS library. Use --tls-max if you want to set a maximum TLS ver-
              sion.

              Added in 7.34.0.

       --tlsv1.1
              (TLS)  Forces curl to use TLS version 1.1 or later when connect-
              ing to a remote TLS server.

              In old versions of curl this  option  was  documented  to  allow
              _only_  TLS  1.1, but behavior was inconsistent depending on the
              TLS library. Use --tls-max if you want to set a maximum TLS ver-
              sion.

              Added in 7.34.0.

       --tlsv1.2
              (TLS)  Forces curl to use TLS version 1.2 or later when connect-
              ing to a remote TLS server.

              In old versions of curl this  option  was  documented  to  allow
              _only_  TLS  1.2, but behavior was inconsistent depending on the
              TLS library. Use --tls-max if you want to set a maximum TLS ver-
              sion.

              Added in 7.34.0.

       --tlsv1.3
              (TLS)  Forces curl to use TLS version 1.3 or later when connect-
              ing to a remote TLS server.

              If the connection is done without TLS, this option  has  no  ef-
              fect. This includes QUIC-using (HTTP/3) transfers.

              Note that TLS 1.3 is not supported by all TLS backends.

              Added in 7.52.0.

       -1, --tlsv1
              (SSL)  Tells curl to use at least TLS version 1.x when negotiat-
              ing with a remote TLS server. That  means  TLS  version  1.0  or
              higher

              See  also  --http1.1  and --http2. -1, --tlsv1 requires that the
              underlying libcurl was built to support TLS. This  option  over-
              rides --tlsv1.1 and --tlsv1.2 and --tlsv1.3.

       --tr-encoding
              (HTTP) Request a compressed Transfer-Encoding response using one
              of the algorithms curl supports, and uncompress the  data  while
              receiving it.

              Added in 7.21.6.

       --trace-ascii <file>
              Enables a full trace dump of all incoming and outgoing data, in-
              cluding descriptive information, to the given output  file.  Use
              "-" as filename to have the output sent to stdout.

              This is very similar to --trace, but leaves out the hex part and
              only shows the ASCII part of the dump. It makes  smaller  output
              that might be easier to read for untrained humans.

              If this option is used several times, the last one will be used.

              This option overrides --trace and -v, --verbose.

       --trace-time
              Prepends  a  time  stamp to each trace or verbose line that curl
              displays.

              Added in 7.14.0.

       --trace <file>
              Enables a full trace dump of all incoming and outgoing data, in-
              cluding  descriptive  information, to the given output file. Use
              "-" as filename to have the output sent to stdout.  Use  "%"  as
              filename to have the output sent to stderr.

              If this option is used several times, the last one will be used.

              This option overrides -v, --verbose and --trace-ascii.

       --unix-socket <path>
              (HTTP) Connect through this Unix domain socket, instead of using
              the network.

              Added in 7.40.0.

       -T, --upload-file <file>
              This transfers the specified local file to the  remote  URL.  If
              there is no file part in the specified URL, curl will append the
              local file name. NOTE that you must use a trailing / on the last
              directory  to really prove to Curl that there is no file name or
              curl will think that your last directory name is the remote file
              name to use. That will most likely cause the upload operation to
              fail. If this is used on an HTTP(S) server, the PUT command will
              be used.

              Use  the file name "-" (a single dash) to use stdin instead of a
              given file.  Alternately, the file name "."  (a  single  period)
              may  be  specified  instead  of "-" to use stdin in non-blocking
              mode to allow reading server output while  stdin  is  being  up-
              loaded.

              You  can  specify one -T, --upload-file for each URL on the com-
              mand line. Each -T, --upload-file + URL pair specifies  what  to
              upload  and  to  where. curl also supports "globbing" of the -T,
              --upload-file argument, meaning that  you  can  upload  multiple
              files  to a single URL by using the same URL globbing style sup-
              ported in the URL, like this:

               curl --upload-file "{file1,file2}" http://www.example.com

              or even

               curl -T "img[1-1000].png" ftp://ftp.example.com/upload/

              When uploading to an SMTP server: the uploaded data  is  assumed
              to be RFC 5322 formatted. It has to feature the necessary set of
              headers and mail body formatted correctly by the  user  as  curl
              will not transcode nor encode it further in any way.

       --url <url>
              Specify  a  URL  to  fetch. This option is mostly handy when you
              want to specify URL(s) in a config file.

              If the given URL is missing a scheme name (such as "http://"  or
              "ftp://"  etc) then curl will make a guess based on the host. If
              the outermost sub-domain name matches  DICT,  FTP,  IMAP,  LDAP,
              POP3  or  SMTP  then  that protocol will be used, otherwise HTTP
              will be used. Since 7.45.0 guessing can be disabled by setting a
              default protocol, see --proto-default for details.

              This  option  may  be used any number of times. To control where
              this URL is written, use the -o, --output or the  -O,  --remote-
              name options.

              Warning:  On  Windows,  particular  file:// accesses can be con-
              verted to network accesses by the operating system. Beware!

       -B, --use-ascii
              (FTP LDAP) Enable ASCII transfer. For FTP, this can also be  en-
              forced  by  using  a  URL  that ends with ";type=A". This option
              causes data sent to stdout to be in text mode for win32 systems.

       -A, --user-agent <name>
              (HTTP) Specify the User-Agent string to send to the HTTP server.
              To  encode blanks in the string, surround the string with single
              quote marks. This header can also be set with the  -H,  --header
              or the --proxy-header options.

              If  you give an empty argument to -A, --user-agent (""), it will
              remove the header completely from the request. If you  prefer  a
              blank header, you can set it to a single space (" ").

              If this option is used several times, the last one will be used.

       -u, --user <user:password>
              Specify the user name and password to use for server authentica-
              tion. Overrides -n, --netrc and --netrc-optional.

              If you simply specify the user name,  curl  will  prompt  for  a
              password.

              The  user  name  and  passwords are split up on the first colon,
              which makes it impossible to use a colon in the user  name  with
              this option. The password can, still.

              On systems where it works, curl will hide the given option argu-
              ment from process listings. This is not enough to  protect  cre-
              dentials  from  possibly getting seen by other users on the same
              system as they will still be visible for a brief  moment  before
              cleared. Such sensitive data should be retrieved from a file in-
              stead or similar and never used in clear text in a command line.
              When using Kerberos V5 with a Windows based  server  you  should
              include  the  Windows domain name in the user name, in order for
              the server to successfully obtain  a  Kerberos  Ticket.  If  you
              don't then the initial authentication handshake may fail.

              When  using  NTLM,  the user name can be specified simply as the
              user name, without the domain, if there is a single  domain  and
              forest in your setup for example.

              To  specify  the domain name use either Down-Level Logon Name or
              UPN (User Principal Name) formats. For example, EXAMPLE\user and
              user@example.com respectively.

              If  you  use a Windows SSPI-enabled curl binary and perform Ker-
              beros V5, Negotiate, NTLM or Digest authentication then you  can
              tell  curl  to select the user name and password from your envi-
              ronment by specifying a single colon with this option: "-u :".

              If this option is used several times, the last one will be used.

       -v, --verbose
              Makes curl verbose during the operation.  Useful  for  debugging
              and  seeing  what's  going  on "under the hood". A line starting
              with '>' means "header data" sent by  curl,  '<'  means  "header
              data"  received  by  curl  that is hidden in normal cases, and a
              line starting with '*' means additional info provided by curl.

              If you only want HTTP headers in the output, -i, --include might
              be the option you're looking for.

              If  you think this option still doesn't give you enough details,
              consider using --trace or --trace-ascii instead.

              Use -s, --silent to make curl really quiet.

              See also  -i,  --include.  This  option  overrides  --trace  and
              --trace-ascii.

       -V, --version
              Displays information about curl and the libcurl version it uses.
              The  first  line  includes the full version of curl, libcurl and
              other 3rd party libraries linked with the executable.

              The second line (starts with "Protocols:") shows  all  protocols
              that libcurl reports to support.

              The third line (starts with "Features:") shows specific features
              libcurl reports to offer. Available features include:

              alt-svc
                     Support for the Alt-Svc: header is provided.

              AsynchDNS
                     This curl uses asynchronous name  resolves.  Asynchronous
                     name  resolves can be done using either the c-ares or the
                     threaded resolver backends.

              brotli Support for automatic brotli compression over HTTP(S).

              CharConv
                     curl was built with support for character set conversions
                     (like EBCDIC)

              Debug  This  curl  uses a libcurl built with Debug. This enables
                     more error-tracking and memory debugging etc.  For  curl-
                     developers only!

              GSS-API
                     GSS-API is supported.

              HTTP2  HTTP/2 support has been built-in.
              HTTP3  HTTP/3 support has been built-in.

              HTTPS-proxy
                     This curl is built to support HTTPS proxy.

              IDN    This curl supports IDN - international domain names.

              IPv6   You can use IPv6 with this.

              krb4   Krb4 for FTP is supported.

              Largefile
                     This curl supports transfers of large files, files larger
                     than 2GB.

              libz   Automatic decompression of compressed files over HTTP  is
                     supported.

              Metalink
                     This curl supports Metalink

              MultiSSL
                     This curl supports multiple TLS backends.

              NTLM   NTLM authentication is supported.
              NTLM   NTLM authentication is supported.

              PSL    PSL  is  short for Public Suffix List and means that this
                     curl has been built with  knowledge  about  "public  suf-
                     fixes".

              SPNEGO SPNEGO authentication is supported.

              SSL    SSL  versions of various protocols are supported, such as
                     HTTPS, FTPS, POP3S and so on.

              SSPI   SSPI is supported.

              TLS-SRP
                     SRP (Secure Remote Password) authentication is  supported
                     for TLS.

              UnixSockets
                     Unix sockets support is provided.

       -w, --write-out <format>
              Make curl display information on stdout after a completed trans-
              fer. The format is a string that may contain  plain  text  mixed
              with  any  number of variables. The format can be specified as a
              literal "string", or you can have curl read the  format  from  a
              file  with  "@filename" and to tell curl to read the format from
              stdin you write "@-".

              The variables present in the output format will  be  substituted
              by  the  value or text that curl thinks fit, as described below.
              All variables are specified as %{variable_name} and to output  a
              normal  % you just write them as %%. You can output a newline by
              using \n, a carriage return with \r and a tab space with \t.

              The output will be written to standard output, but this  can  be
              switched to standard error by using %{stderr}.

              NOTE: The %-symbol is a special symbol in the win32-environment,
              where all occurrences of % must be doubled when using  this  op-
              tion.

              The variables available are:

              content_type   The  Content-Type  of  the requested document, if
                             there was any.

              filename_effective
                             The ultimate filename that curl  writes  out  to.
                             This  is only meaningful if curl is told to write
                             to a file  with  the  -O,  --remote-name  or  -o,
                             --output  option. It's most useful in combination
                             with the -J, --remote-header-name option.  (Added
                             in 7.26.0)

              ftp_entry_path The initial path curl ended up in when logging on
                             to the remote FTP server. (Added in 7.15.4)

              http_code      The numerical response code that was found in the
                             last  retrieved  HTTP(S)  or  FTP(s) transfer. In
                             7.18.2 the alias response_code was added to  show
                             the same info.

              http_connect   The numerical code that was found in the last re-
                             sponse (from a proxy) to a curl CONNECT  request.
                             (Added in 7.12.4)

              http_version   The  http  version  that  was  effectively  used.
                             (Added in 7.50.0)

              json           A JSON object with all available keys.

              local_ip       The IP address of the local end of the  most  re-
                             cently  done  connection  - can be either IPv4 or
                             IPv6 (Added in 7.29.0)

              local_port     The local port number of the most  recently  done
                             connection (Added in 7.29.0)

              method         The  http method used in the most recent HTTP re-
                             quest (Added in 7.72.0)

              num_connects   Number of new connects made in the recent  trans-
                             fer. (Added in 7.12.3)

              num_redirects  Number of redirects that were followed in the re-
                             quest. (Added in 7.12.3)

              proxy_ssl_verify_result
                             The result of the HTTPS proxy's SSL peer certifi-
                             cate verification that was requested. 0 means the
                             verification was successful. (Added in 7.52.0)

              redirect_url   When an HTTP request was made without -L, --loca-
                             tion  to follow redirects (or when --max-redir is
                             met), this variable will show the  actual  URL  a
                             redirect would have gone to. (Added in 7.18.2)

              remote_ip      The  remote  IP address of the most recently done
                             connection - can be either IPv4 or IPv6 (Added in
                             7.29.0)

              remote_port    The  remote port number of the most recently done
                             connection (Added in 7.29.0)

              response_code  The numerical response code that was found in the
                             last  transfer  (formerly  known as "http_code").
                             (Added in 7.18.2)

              scheme         The URL scheme (sometimes called  protocol)  that
                             was effectively used (Added in 7.52.0)

              size_download  The total amount of bytes that were downloaded.

              size_header    The total amount of bytes of the downloaded head-
                             ers.

              size_request   The total amount of bytes that were sent  in  the
                             HTTP request.

              size_upload    The total amount of bytes that were uploaded.

              speed_download The average download speed that curl measured for
                             the complete download. Bytes per second.

              speed_upload   The average upload speed that curl  measured  for
                             the complete upload. Bytes per second.

              ssl_verify_result
                             The  result of the SSL peer certificate verifica-
                             tion that was requested. 0 means the verification
                             was successful. (Added in 7.19.0)

              stderr         From  this  point  on, the -w, --write-out output
                             will be written  to  standard  error.  (Added  in
                             7.63.0)

              stdout         From  this  point  on, the -w, --write-out output
                             will be written to standard output.  This is  the
                             default,  but  can  be  used to switch back after
                             switching to stderr.  (Added in 7.63.0)

              time_appconnect
                             The time, in seconds, it took from the start  un-
                             til  the SSL/SSH/etc connect/handshake to the re-
                             mote host was completed. (Added in 7.19.0)

              time_connect   The time, in seconds, it took from the start  un-
                             til the TCP connect to the remote host (or proxy)
                             was completed.

              time_namelookup
                             The time, in seconds, it took from the start  un-
                             til the name resolving was completed.

              time_pretransfer
                             The  time, in seconds, it took from the start un-
                             til the file transfer was just  about  to  begin.
                             This includes all pre-transfer commands and nego-
                             tiations that are specific to the particular pro-
                             tocol(s) involved.

              time_redirect  The time, in seconds, it took for all redirection
                             steps including name lookup, connect, pretransfer
                             and  transfer  before  the  final transaction was
                             started. time_redirect shows the complete  execu-
                             tion  time  for  multiple redirections. (Added in
                             7.12.3)

              time_starttransfer
                             The time, in seconds, it took from the start  un-
                             til  the  first  byte was just about to be trans-
                             ferred. This includes time_pretransfer  and  also
                             the  time  the server needed to calculate the re-
                             sult.

              time_total     The total time, in seconds, that the full  opera-
                             tion lasted.

              url_effective  The URL that was fetched last. This is most mean-
                             ingful if you've told curl  to  follow  location:
                             headers.

              If this option is used several times, the last one will be used.

       --xattr
              When  saving  output  to a file, this option tells curl to store
              certain file metadata in extended  file  attributes.  Currently,
              the URL is stored in the xdg.origin.url attribute and, for HTTP,
              the content type is stored in the mime_type  attribute.  If  the
              file  system  does not support extended attributes, a warning is
              issued.

FILES
       ~/.curlrc
              Default config file, see -K, --config for details.

ENVIRONMENT
       The environment variables can be specified in lower case or upper case.
       The lower case version has precedence. http_proxy is an exception as it
       is only available in lower case.

       Using an environment variable to set the proxy has the same  effect  as
       using the -x, --proxy option.

       http_proxy [protocol://]<host>[:port]
              Sets the proxy server to use for HTTP.
       HTTPS_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use for HTTPS.

       [url-protocol]_PROXY [protocol://]<host>[:port]
              Sets  the proxy server to use for [url-protocol], where the pro-
              tocol is a protocol that curl supports and  as  specified  in  a
              URL. FTP, FTPS, POP3, IMAP, SMTP, LDAP etc.

       ALL_PROXY [protocol://]<host>[:port]
              Sets  the  proxy  server to use if no protocol-specific proxy is
              set.

       NO_PROXY <comma-separated list of hosts/domains>
              list of host names that shouldn't go through any proxy.  If  set
              to an asterisk '*' only, it matches all hosts. Each name in this
              list is matched as either a domain name which contains the host-
              name, or the hostname itself.

              This  environment  variable  disables use of the proxy even when
              specified with the -x,  --proxy  option.  That  is  NO_PROXY=di-
              rect.example.com  curl  -x  http://proxy.example.com  http://di-
              rect.example.com  accesses  the   target   URL   directly,   and
              NO_PROXY=direct.example.com   curl  -x  http://proxy.example.com
              http://somewhere.example.com accesses the target URL through the
              proxy.

              The  list  of  host  names  can also be include numerical IP ad-
              dresses, and IPv6 versions should then be given without  enclos-
              ing brackets.

       CURL_SSL_BACKEND <TLS backend>
              If  curl  was built with support for "MultiSSL", meaning that it
              has built-in support for more than one TLS backend,  this  envi-
              ronment  variable can be set to the case insensitive name of the
              particular backend to use when curl is invokved. Setting a  name
              that  isn't a built-in alternative, will make curl stay with the
              default.

       QLOGDIR <directory name>
              If curl was built with HTTP/3 support, setting this  environment
              variable  to  a  local directory will make curl produce qlogs in
              that directory, using file names  named  after  the  destination
              connection  id  (in  hex).  Do  note that these files can become
              rather large. Works with both QUIC backends.

       SSLKEYLOGFILE <file name>
              If you set this environment variable to a file name,  curl  will
              store TLS secrets from its connections in that file when invoked
              to enable you to analyze the TLS traffic in real time using net-
              work analyzing tools such as Wireshark. This works with the fol-
              lowing TLS backends: OpenSSL, libressl, BoringSSL,  GnuTLS,  NSS
              and wolfSSL.

PROXY PROTOCOL PREFIXES
       Since  curl  version  7.21.7,  the proxy string may be specified with a
       protocol:// prefix to specify alternative proxy protocols.

       If no protocol is specified in  the  proxy  string  or  if  the  string
       doesn't  match  a  supported  one, the proxy will be treated as an HTTP
       proxy.

       The supported proxy protocol prefixes are as follows:

       http://
              Makes it use it as an HTTP proxy. The default if no scheme  pre-
              fix is used.

       https://
              Makes it treated as an HTTPS proxy.

       socks4://
              Makes it the equivalent of --socks4

       socks4a://
              Makes it the equivalent of --socks4a

       socks5://
              Makes it the equivalent of --socks5

       socks5h://
              Makes it the equivalent of --socks5-hostname

EXIT CODES
       There  are a bunch of different error codes and their corresponding er-
       ror messages that may appear during bad conditions. At the time of this
       writing, the exit codes are:

       1      Unsupported protocol. This build of curl has no support for this
              protocol.

       2      Failed to initialize.

       3      URL malformed. The syntax was not correct.

       4      A feature or option that was needed to perform the  desired  re-
              quest  was not enabled or was explicitly disabled at build-time.
              To make curl able to do this, you probably need another build of
              libcurl!

       5      Couldn't  resolve  proxy.  The given proxy host could not be re-
              solved.

       6      Couldn't resolve host. The given remote host was not resolved.

       7      Failed to connect to host.

       8      Weird server reply. The server sent data curl couldn't parse.

       9      FTP access denied. The server denied login or denied  access  to
              the  particular  resource or directory you wanted to reach. Most
              often you tried to change to a directory that doesn't  exist  on
              the server.

       10     FTP  accept failed. While waiting for the server to connect back
              when an active FTP session is used, an error code was sent  over
              the control connection or similar.

       11     FTP  weird PASS reply. Curl couldn't parse the reply sent to the
              PASS request.

       12     During an active FTP session while waiting  for  the  server  to
              connect back to curl, the timeout expired.

       13     FTP  weird PASV reply, Curl couldn't parse the reply sent to the
              PASV request.

       14     FTP weird 227 format.  Curl  couldn't  parse  the  227-line  the
              server sent.

       15     FTP  can't  get host. Couldn't resolve the host IP we got in the
              227-line.

       16     HTTP/2 error. A problem was detected in the HTTP2 framing layer.
              This is somewhat generic and can be one out of several problems,
              see the error message for details.

       17     FTP couldn't set binary. Couldn't change transfer method to  bi-
              nary.

       18     Partial file. Only a part of the file was transferred.

       19     FTP  couldn't download/access the given file, the RETR (or simi-
              lar) command failed.

       21     FTP quote error. A quote command returned error from the server.
       22     HTTP page not retrieved. The requested url was not found or  re-
              turned  another  error  with  the  HTTP  error code being 400 or
              above. This return code only appears if -f, --fail is used.

       23     Write error. Curl couldn't write data to a local  filesystem  or
              similar.

       25     FTP  couldn't  STOR  file. The server denied the STOR operation,
              used for FTP uploading.

       26     Read error. Various reading problems.

       27     Out of memory. A memory allocation request failed.

       28     Operation timeout. The specified time-out period was reached ac-
              cording to the conditions.

       30     FTP  PORT  failed.  The PORT command failed. Not all FTP servers
              support the PORT command, try doing a transfer  using  PASV  in-
              stead!

       31     FTP  couldn't use REST. The REST command failed. This command is
              used for resumed FTP transfers.

       33     HTTP range error. The range "command" didn't work.

       34     HTTP post error. Internal post-request generation error.

       35     SSL connect error. The SSL handshaking failed.

       36     Bad download resume. Couldn't continue an earlier aborted  down-
              load.

       37     FILE couldn't read file. Failed to open the file. Permissions?

       38     LDAP cannot bind. LDAP bind operation failed.

       39     LDAP search failed.

       41     Function not found. A required LDAP function was not found.

       42     Aborted by callback. An application told curl to abort the oper-
              ation.

       43     Internal error. A function was called with a bad parameter.

       45     Interface error. A specified outgoing  interface  could  not  be
              used.

       47     Too many redirects. When following redirects, curl hit the maxi-
              mum amount.

       48     Unknown option specified to libcurl.  This  indicates  that  you
              passed  a weird option to curl that was passed on to libcurl and
              rejected. Read up in the manual!

       49     Malformed telnet option.

       51     The peer's SSL certificate or SSH MD5 fingerprint was not OK.

       52     The server didn't reply anything, which here  is  considered  an
              error.

       53     SSL crypto engine not found.

       54     Cannot set SSL crypto engine as default.

       55     Failed sending network data.

       56     Failure in receiving network data.

       58     Problem with the local certificate.

       59     Couldn't use specified SSL cipher.

       60     Peer  certificate cannot be authenticated with known CA certifi-
              cates.

       61     Unrecognized transfer encoding.

       62     Invalid LDAP URL.

       63     Maximum file size exceeded.

       64     Requested FTP SSL level failed.

       65     Sending the data requires a rewind that failed.

       66     Failed to initialise SSL Engine.

       67     The user name, password, or similar was not  accepted  and  curl
              failed to log in.

       68     File not found on TFTP server.

       69     Permission problem on TFTP server.

       70     Out of disk space on TFTP server.

       71     Illegal TFTP operation.

       72     Unknown TFTP transfer ID.

       73     File already exists (TFTP).

       74     No such user (TFTP).

       75     Character conversion failed.

       76     Character conversion functions required.

       77     Problem with reading the SSL CA cert (path? access rights?).

       78     The resource referenced in the URL does not exist.

       79     An unspecified error occurred during the SSH session.

       80     Failed to shut down the SSL connection.

       82     Could  not  load  CRL  file,  missing  or wrong format (added in
              7.19.0).

       83     Issuer check failed (added in 7.19.0).

       84     The FTP PRET command failed

       85     RTSP: mismatch of CSeq numbers

       86     RTSP: mismatch of Session Identifiers

       87     unable to parse FTP file list

       88     FTP chunk callback reported error

       89     No connection available, the session will be queued

       90     SSL public key does not matched pinned public key

       91     Invalid SSL certificate status.

       92     Stream error in HTTP/2 framing layer.

       93     An API function was called from inside a callback.

       94     An authentication function returned an error.

       95     A problem was detected in the HTTP/3  layer.  This  is  somewhat
              generic  and  can  be one out of several problems, see the error
              message for details.

       96     QUIC connection error. This error may be caused by  an  SSL  li-
              brary error. QUIC is the protocol used for HTTP/3 transfers.

       XX     More error codes will appear here in future releases. The exist-
              ing ones are meant to never change.

AUTHORS / CONTRIBUTORS
       Daniel Stenberg is the main author, but the whole list of  contributors
       is found in the separate THANKS file.

WWW
       https://curl.haxx.se

SEE ALSO
       ftp(1), wget(1)

