docs/cmdline-opts/page-header - platform/external/curl - Git at Google

 .\" **************************************************************************
 .\" *                                  _   _ ____  _
 .\" *  Project                     ___| | | |  _ \| |
 .\" *                             / __| | | | |_) | |
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
 .\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
 .\" * are also available at https://curl.se/docs/copyright.html.
 .\" *
 .\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 .\" * copies of the Software, and permit persons to whom the Software is
 .\" * furnished to do so, under the terms of the COPYING file.
 .\" *
 .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 .\" * KIND, either express or implied.
 .\" *
 .\" * SPDX-License-Identifier: curl
 .\" *
 .\" **************************************************************************
 .\"
 .\" DO NOT EDIT. Generated by the curl project gen.pl man page generator.
 .\"
 .TH curl 1 "%DATE" "curl %VERSION" "curl Manual"
 .SH NAME
 curl \- transfer a URL
 .SH SYNOPSIS
 .B curl [options / URLs]
 .SH DESCRIPTION
 **curl** is a tool for transferring data from or to a server using URLs. It
 supports these protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS,
 IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP,
 SMB, SMBS, SMTP, SMTPS, TELNET, TFTP, WS and WSS.

 curl is powered by libcurl for all transfer-related features. See
 *libcurl(3)* for details.
 .SH URL
 The URL syntax is protocol-dependent. You find a detailed description in
 RFC 3986.

 If you provide a URL without a leading **protocol://** scheme, curl guesses
 what protocol you want. It then defaults to HTTP but assumes others based on
 often-used host name prefixes. For example, for host names starting with
 "ftp." curl assumes you want FTP.

 You can specify any amount of URLs on the command line. They are fetched in a
 sequential manner in the specified order unless you use --parallel. You can
 specify command line options and URLs mixed and in any order on the command
 line.

 curl attempts to reuse connections when doing multiple transfers, so that
 getting many files from the same server do not use multiple connects and setup
 handshakes. This improves speed. Connection reuse can only be done for URLs
 specified for a single command line invocation and cannot be performed between
 separate curl runs.

 Provide an IPv6 zone id in the URL with an escaped percentage sign. Like in

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

 Everything provided on the command line that is not a command line option or
 its argument, curl assumes is a URL and treats it as such.
 .SH GLOBBING
 You can specify multiple URLs or parts of URLs by writing lists within braces
 or ranges within brackets. We call this "globbing".

 Provide a list with three different names like this:

   "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 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 '*'.

 Switch off globbing with --globoff.
 .SH VARIABLES
 curl supports command line variables (added in 8.3.0). Set variables with
 --variable name=content or --variable name@file (where "file" can be stdin if
 set to a single dash (-)).

 Variable contents can expanded in option parameters using "{{name}}" (without
 the quotes) if the option name is prefixed with "--expand-". This gets the
 contents of the variable "name" inserted, or a blank if the name does not
 exist as a variable. Insert "{{" verbatim in the string by prefixing it with a
 backslash, like "\\{{".

 You an access and expand environment variables by first importing them. You
 can select to either require the environment variable to be set or you can
 provide a default value in case it is not already set. Plain --variable %name
 imports the variable called 'name' but exits with an error if that environment
 variable is not already set. To provide a default value if it is not set, use
 --variable %name=content or --variable %name@content.

 Example. Get the USER environment variable into the URL, fail if USER is not
 set:

  --variable '%USER'
  --expand-url = "https://example.com/api/{{USER}}/method"

 When expanding variables, curl supports a set of functions that can make the
 variable contents more convenient to use. It can trim leading and trailing
 white space with *trim*, it can output the contents as a JSON quoted string
 with *json*, URL encode the string with *url* or base64 encode it with
 *b64*. You apply function to a variable expansion, add them colon separated to
 the right side of the variable. Variable content holding null bytes that are
 not encoded when expanded cause error.

 Example: get the contents of a file called $HOME/.secret into a variable
 called "fix". Make sure that the content is trimmed and percent-encoded sent
 as POST data:

   --variable %HOME
   --expand-variable fix@{{HOME}}/.secret
   --expand-data "{{fix:trim:url}}"
   https://example.com/

 Command line variables and expansions were added in in 8.3.0.
 .SH OUTPUT
 If not told otherwise, curl writes the received data to stdout. It can be
 instructed to instead save that data into a local file, using the --output or
 --remote-name options. If curl is given multiple URLs to transfer on the
 command line, it similarly needs multiple options for where to save them.

 curl does not parse or otherwise "understand" the content it gets or writes as
 output. It does no encoding or decoding, unless explicitly asked to with
 dedicated command line options.
 .SH PROTOCOLS
 curl supports numerous protocols, or put in URL terms: schemes. Your
 particular build may not support them all.
 .IP DICT
 Lets you lookup words using online dictionaries.
 .IP FILE
 Read or write local files. curl does not support accessing file:// URL
 remotely, but when running on Microsoft Windows using the native UNC approach
 works.
 .IP FTP(S)
 curl supports the File Transfer Protocol with a lot of tweaks and levers. With
 or without using TLS.
 .IP GOPHER(S)
 Retrieve files.
 .IP 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 options and the correct
 command line options.
 .IP IMAP(S)
 Using the mail reading protocol, curl can "download" emails for you. With or
 without using TLS.
 .IP LDAP(S)
 curl can do directory lookups for you, with or without TLS.
 .IP MQTT
 curl supports MQTT version 3. Downloading over MQTT equals "subscribe" to a
 topic while uploading/posting equals "publish" on a topic. MQTT over TLS is
 not supported (yet).
 .IP POP3(S)
 Downloading from a pop3 server means getting a mail. With or without using
 TLS.
 .IP RTMP(S)
 The **Realtime Messaging Protocol** is primarily used to serve streaming media
 and curl can download it.
 .IP RTSP
 curl supports RTSP 1.0 downloads.
 .IP SCP
 curl supports SSH version 2 scp transfers.
 .IP SFTP
 curl supports SFTP (draft 5) done over SSH version 2.
 .IP SMB(S)
 curl supports SMB version 1 for upload and download.
 .IP SMTP(S)
 Uploading contents to an SMTP server means sending an email. With or without
 TLS.
 .IP 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.
 .IP TFTP
 curl can do TFTP downloads and uploads.
 .SH "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 the transfer rate 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 (>), --output or
 similar.

 This does not apply to 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
 --silent option.
 .SH VERSION
 This man page describes curl %VERSION. If you use a later version, chances are
 this man page does not fully document it. If you use an earlier version, this
 document tries to include version information about which specific version
 that introduced changes.

 You can always learn which the latest curl version is by running

   curl https://curl.se/info

 The online version of this man page is always showing the latest incarnation:
 https://curl.se/docs/manpage.html
 .SH OPTIONS
 Options start with one or two dashes. Many of the options require an
 additional value next to them. If provided text does not start with a dash, it
 is presumed to be and treated as a URL.

 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, --data for example, requires a space
 between it and its value.

 Short version options that do not 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 same option name but
 prefix it with "no-". However, in this list we mostly only list and show the
 *--option* version of them.

 When --next is used, it resets the parser state and you start again with a
 clean option state, except for the options that are "global". Global options
 retain their values and meaning even after --next.

 The following options are global:
 %GLOBALS.
	.\" **************************************************************************
	.\" * _ _ ____ _
	.\" * Project ___\| \| \| \| _ \\| \|
	.\" * / __\| \| \| \| \|_) \| \|
	.\" * \| (__\| \|_\| \| _ <\| \|___
	.\" * \___\|\___/\|_\| \_\_____\|
	.\" *
	.\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
	.\" *
	.\" * This software is licensed as described in the file COPYING, which
	.\" * you should have received as part of this distribution. The terms
	.\" * are also available at https://curl.se/docs/copyright.html.
	.\" *
	.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
	.\" * copies of the Software, and permit persons to whom the Software is
	.\" * furnished to do so, under the terms of the COPYING file.
	.\" *
	.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
	.\" * KIND, either express or implied.
	.\" *
	.\" * SPDX-License-Identifier: curl
	.\" *
	.\" **************************************************************************
	.\"
	.\" DO NOT EDIT. Generated by the curl project gen.pl man page generator.
	.\"
	.TH curl 1 "%DATE" "curl %VERSION" "curl Manual"
	.SH NAME
	curl \- transfer a URL
	.SH SYNOPSIS
	.B curl [options / URLs]
	.SH DESCRIPTION
	curl is a tool for transferring data from or to a server using URLs. It
	supports these protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS,
	IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP,
	SMB, SMBS, SMTP, SMTPS, TELNET, TFTP, WS and WSS.

	curl is powered by libcurl for all transfer-related features. See
	libcurl(3) for details.
	.SH URL
	The URL syntax is protocol-dependent. You find a detailed description in
	RFC 3986.

	If you provide a URL without a leading protocol:// scheme, curl guesses
	what protocol you want. It then defaults to HTTP but assumes others based on
	often-used host name prefixes. For example, for host names starting with
	"ftp." curl assumes you want FTP.

	You can specify any amount of URLs on the command line. They are fetched in a
	sequential manner in the specified order unless you use --parallel. You can
	specify command line options and URLs mixed and in any order on the command
	line.

	curl attempts to reuse connections when doing multiple transfers, so that
	getting many files from the same server do not use multiple connects and setup
	handshakes. This improves speed. Connection reuse can only be done for URLs
	specified for a single command line invocation and cannot be performed between
	separate curl runs.

	Provide an IPv6 zone id in the URL with an escaped percentage sign. Like in

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

	Everything provided on the command line that is not a command line option or
	its argument, curl assumes is a URL and treats it as such.
	.SH GLOBBING
	You can specify multiple URLs or parts of URLs by writing lists within braces
	or ranges within brackets. We call this "globbing".

	Provide a list with three different names like this:

	"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 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 '*'.

	Switch off globbing with --globoff.
	.SH VARIABLES
	curl supports command line variables (added in 8.3.0). Set variables with
	--variable name=content or --variable name@file (where "file" can be stdin if
	set to a single dash (-)).

	Variable contents can expanded in option parameters using "{{name}}" (without
	the quotes) if the option name is prefixed with "--expand-". This gets the
	contents of the variable "name" inserted, or a blank if the name does not
	exist as a variable. Insert "{{" verbatim in the string by prefixing it with a
	backslash, like "\\{{".

	You an access and expand environment variables by first importing them. You
	can select to either require the environment variable to be set or you can
	provide a default value in case it is not already set. Plain --variable %name
	imports the variable called 'name' but exits with an error if that environment
	variable is not already set. To provide a default value if it is not set, use
	--variable %name=content or --variable %name@content.

	Example. Get the USER environment variable into the URL, fail if USER is not
	set:

	--variable '%USER'
	--expand-url = "https://example.com/api/{{USER}}/method"

	When expanding variables, curl supports a set of functions that can make the
	variable contents more convenient to use. It can trim leading and trailing
	white space with trim, it can output the contents as a JSON quoted string
	with json, URL encode the string with url or base64 encode it with
	b64. You apply function to a variable expansion, add them colon separated to
	the right side of the variable. Variable content holding null bytes that are
	not encoded when expanded cause error.

	Example: get the contents of a file called $HOME/.secret into a variable
	called "fix". Make sure that the content is trimmed and percent-encoded sent
	as POST data:

	--variable %HOME
	--expand-variable fix@{{HOME}}/.secret
	--expand-data "{{fix:trim:url}}"
	https://example.com/

	Command line variables and expansions were added in in 8.3.0.
	.SH OUTPUT
	If not told otherwise, curl writes the received data to stdout. It can be
	instructed to instead save that data into a local file, using the --output or
	--remote-name options. If curl is given multiple URLs to transfer on the
	command line, it similarly needs multiple options for where to save them.

	curl does not parse or otherwise "understand" the content it gets or writes as
	output. It does no encoding or decoding, unless explicitly asked to with
	dedicated command line options.
	.SH PROTOCOLS
	curl supports numerous protocols, or put in URL terms: schemes. Your
	particular build may not support them all.
	.IP DICT
	Lets you lookup words using online dictionaries.
	.IP FILE
	Read or write local files. curl does not support accessing file:// URL
	remotely, but when running on Microsoft Windows using the native UNC approach
	works.
	.IP FTP(S)
	curl supports the File Transfer Protocol with a lot of tweaks and levers. With
	or without using TLS.
	.IP GOPHER(S)
	Retrieve files.
	.IP 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 options and the correct
	command line options.
	.IP IMAP(S)
	Using the mail reading protocol, curl can "download" emails for you. With or
	without using TLS.
	.IP LDAP(S)
	curl can do directory lookups for you, with or without TLS.
	.IP MQTT
	curl supports MQTT version 3. Downloading over MQTT equals "subscribe" to a
	topic while uploading/posting equals "publish" on a topic. MQTT over TLS is
	not supported (yet).
	.IP POP3(S)
	Downloading from a pop3 server means getting a mail. With or without using
	TLS.
	.IP RTMP(S)
	The Realtime Messaging Protocol is primarily used to serve streaming media
	and curl can download it.
	.IP RTSP
	curl supports RTSP 1.0 downloads.
	.IP SCP
	curl supports SSH version 2 scp transfers.
	.IP SFTP
	curl supports SFTP (draft 5) done over SSH version 2.
	.IP SMB(S)
	curl supports SMB version 1 for upload and download.
	.IP SMTP(S)
	Uploading contents to an SMTP server means sending an email. With or without
	TLS.
	.IP 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.
	.IP TFTP
	curl can do TFTP downloads and uploads.
	.SH "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 the transfer rate 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 (>), --output or
	similar.

	This does not apply to 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
	--silent option.
	.SH VERSION
	This man page describes curl %VERSION. If you use a later version, chances are
	this man page does not fully document it. If you use an earlier version, this
	document tries to include version information about which specific version
	that introduced changes.

	You can always learn which the latest curl version is by running

	curl https://curl.se/info

	The online version of this man page is always showing the latest incarnation:
	https://curl.se/docs/manpage.html
	.SH OPTIONS
	Options start with one or two dashes. Many of the options require an
	additional value next to them. If provided text does not start with a dash, it
	is presumed to be and treated as a URL.

	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, --data for example, requires a space
	between it and its value.

	Short version options that do not 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 same option name but
	prefix it with "no-". However, in this list we mostly only list and show the
	--option version of them.

	When --next is used, it resets the parser state and you start again with a
	clean option state, except for the options that are "global". Global options
	retain their values and meaning even after --next.

	The following options are global:
	%GLOBALS.