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curl(1)

NAME

   curl - transfer a URL

SYNOPSIS

   curl [options] [URL...]

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,  POP3,  POP3S,  RTMP, 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
   authentication, FTP upload, HTTP post, SSL connections,  cookies,  file
   transfer  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
   description in RFC 3986.

   You can specify multiple URLs or parts of URLs  by  writing  part  sets
   within braces 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 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
   example,  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
   connects / 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.

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
   [file] 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, -# is your
   friend.

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, --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
repeated use of the same command line option.)

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

-:, --next
Tells curl to use a separate operation for the following URL and
associated options. This allows you to send several URL
requests, each with their own specific options, for example,
such as different user names or custom requests for each. (Added
in 7.36.0)

-0, --http1.0
(HTTP) Tells curl to use HTTP version 1.0 instead of using its
internally preferred: HTTP 1.1.

--http1.1
(HTTP) Tells curl to use HTTP version 1.1. This is the internal
default version. (Added in 7.33.0)

--http2
(HTTP) Tells curl to issue its requests using HTTP 2. This
requires that the underlying libcurl was built to support it.
(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.

HTTP/2 support in general also requires that the underlying
libcurl was built to support it. (Added in 7.49.0)

--no-npn
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.

(Added in 7.36.0)

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

(Added in 7.36.0)

-1, --tlsv1
(SSL) Forces curl to use TLS version 1.x when negotiating with a
remote TLS server. You can use options --tlsv1.0, --tlsv1.1,
and --tlsv1.2 to control the TLS version more precisely (if the
SSL backend in use supports such a level of control).

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

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

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

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

-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
ignored by some SFTP servers (including OpenSSH).

-A, --user-agent <agent string>
(HTTP) Specify the User-Agent string to send to the HTTP server.
Some badly done CGIs fail if this field isn't set to
"Mozilla/4.0". To encode blanks in the string, surround the
string with single quote marks. This can also be set with the
-H, --header option of course.

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

--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.

Note that 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.

-b, --cookie <name=data>
(HTTP) Pass the data to the HTTP server as a cookie. 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 line, it is treated as a
filename to use to read previously stored cookie lines from,
which should be used in this session if they match. Using this
method also activates the cookie engine which will make curl
record incoming cookies too, which may be handy if you're using
this in combination with the -L, --location option. 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
domain 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.

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

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

Used together with -u, --user and -x, --proxy.

See also the -m, --max-time option.

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

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

To create remote directories when using FTP or SFTP, try --ftp-
create-dirs.

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

(SMTP added in 7.40.0)

--crlfile <file>
(HTTPS/FTPS) Provide a file using PEM format with a Certificate
Revocation List that may specify peer certificates that are to
be considered revoked.

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

(Added in 7.19.7)

-d, --data <data>
(HTTP) 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.

-d, --data is the same as --data-ascii. --data-raw is almost the
same but does not have a special interpretation 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
command 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. Multiple files can also be specified.
Posting data from a file named 'foobar' would thus be done with
--data @foobar. When --data is told to read from a file like
that, carriage returns and newlines will be stripped out. If you
don't want the @ character to have a special interpretation use
--data-raw instead.

-D, --dump-header <file>
Write the 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.

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.

--data-ascii <data>
See -d, --data.

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

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

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 --data but without the
special interpretation of the @ character. See -d, --data.
(Added in 7.43.0)

--data-urlencode <data>
(HTTP) This posts data, similar to the other --data options with
the exception that this performs URL-encoding. (Added in 7.18.0)

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
(including 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
(including any newlines), URL-encode that data and pass
it on in the POST. The name part gets an equal sign
appended, resulting in name=urlencoded-file-content. Note
that the name is expected to be URL-encoded already.

--delegation LEVEL
Set LEVEL to tell the server what it is allowed to delegate when
it comes to user credentials. Used with GSS/kerberos.

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
authentication 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. See also
--ntlm, --negotiate and --anyauth for related options.

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

--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
extensions 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 an IPv6 host, 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) 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.

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

This option requires that libcurl was built with a resolver
backend that supports this operation. The c-ares backend is the
only such one. (Added in 7.33.0)

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

This option requires that libcurl was built with a resolver
backend that supports this operation. The c-ares backend is the
only such one. (Added in 7.33.0)

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

This option requires that libcurl was built with a resolver
backend that supports this operation. The c-ares backend is the
only such one. (Added in 7.33.0)

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

This option requires that libcurl was built with a resolver
backend that supports this operation. The c-ares backend is the
only such one. (Added in 7.33.0)

-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 --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 --referer.

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

-E, --cert <certificate[:password]>
(SSL) Tells curl to use the specified client certificate file
when getting a file with HTTPS, FTPS or another SSL-based
protocol. The certificate must be in PKCS#12 format if using
Secure Transport, or PEM format if using any other engine. If
the optional 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 --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
(libnsspem.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
nickname contains "\", it needs to be escaped as "\\" so that it
is not recognized as an escape character.

(iOS and macOS only) If curl is built against Secure Transport,
then the certificate string can either be the name of a
certificate/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.

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

--engine <name>
Select the OpenSSL crypto engine to use for cipher operations.
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.

--environment
(RISC OS ONLY) Sets a range of environment variables, using the
names the -w option supports, to allow easier extraction of
useful information after having run curl.

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

--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.

(Added in 7.47.0)

--cert-type <type>
(SSL) Tells curl what certificate type the provided certificate
is in. PEM, DER and ENG are recognized types. If not specified,
PEM is assumed.

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

--cacert <CA certificate>
(SSL) 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
directory 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
option 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.

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

--capath <CA certificate directory>
(SSL) 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
directory must have been processed using the c_rehash utility
supplied 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.

--pinnedpubkey <pinned public key (hashes)>
(SSL) 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
separated 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
public 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/CyaSSL
7.47.0: mbedtls
7.49.0: PolarSSL sha256 support:
7.44.0: OpenSSL, GnuTLS, NSS and wolfSSL/CyaSSL.
7.47.0: mbedtls
7.49.0: PolarSSL Other SSL backends not supported.

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

--cert-status
(SSL) 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
certificate 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)

--false-start

(SSL) Tells curl to use false start during the TLS handshake.
False start is a mode where a TLS client will start sending
application 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
Transport (on iOS 7.0 or later, or OS X 10.9 or later) backends.
(Added in 7.42.0)

-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
prevent 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
authentication is involved (response codes 401 and 407).

-F, --form <name=content>
(HTTP) This lets curl emulate 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. This enables uploading of binary files etc. To force the
'content' 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.

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

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

To read content from stdin instead of a file, use - as the
filename. This goes for both @ and < constructs. Unfortunately
it does not support reading the file from a named pipe or
similar, as it needs the full size before the transfer starts.

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

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
double-quotes like:

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

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.

See further examples and details in the MANUAL.

This option can be used multiple times.

--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. (Added in 7.13.0)

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

--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.

--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
following 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
commands. 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. (Added in 7.11.0)

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.

--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
already uses for the control connection. (Added in 7.14.2)

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

--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.x)

--ftp-ssl-ccc
(FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS
layer after authenticating. The rest of the control channel
communication will be unencrypted. This allows NAT routers to
follow the FTP transaction. The default mode is passive. See
--ftp-ssl-ccc-mode for other modes. (Added in 7.16.1)

--ftp-ssl-ccc-mode [active/passive]
(FTP) Use CCC (Clear Command Channel) 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. (Added in 7.16.2)

--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
support SSL/TLS. (Added in 7.16.0) that can still be used but
will be removed in a future version.

--ftp-ssl
(FTP) This deprecated option is now known as --ssl.

--ftp-ssl-reqd
(FTP) This deprecated option is now known as --ssl-reqd.

--form-string <name=string>
(HTTP) Similar to --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 --form if there's any
possibility that the string value may accidentally trigger the
'@' or '<' features of --form.

-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.

-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, the POST data will instead 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.

-H, --header <header>
(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
perfectly well what you're doing. Remove an internal header by
giving 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.

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

Starting in 7.37.0, you need --proxy-header to send custom
headers 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
requests - 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.

--hostpubmd5 <md5>
(SCP/SFTP) 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)

--ignore-content-length
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 gigabytes.

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

-i, --include
(HTTP) Include the HTTP-header in the output. The HTTP-header
includes things like server-name, date of the document, HTTP-
version and more...

-I, --head
(HTTP/FTP/FILE) Fetch the HTTP-header 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.

--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.

-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
basically have the same effect as if a new session is started.
Typical browsers always discard session cookies when they're
closed down.

-J, --remote-header-name
(HTTP) This option tells the -O, --remote-name option to use the
server-specified Content-Disposition filename instead of
extracting 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
specify 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
Windows or some third party software.

-k, --insecure
(SSL) This option explicitly allows curl to perform "insecure"
SSL connections and transfers. All SSL connections are attempted
to be made secure by using the CA certificate bundle installed
by default. This makes all connections considered "insecure"
fail unless -k, --insecure is used.

See this online resource for further details:
https://curl.haxx.se/docs/sslcerts.html

-K, --config <config file>
Specify which config file to read curl arguments from. The
config file is a text file in which command line arguments can
be written which then will be used as if they were written on
the actual command line.

Options and their parameters must be specified on the same
config file line, 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 character between the option and its parameter.

If the parameter is to contain whitespace, 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 ignored. 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 always (unless -q is used) checks for a
default config file and uses it if found. The default config
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
'%USERPROFILE%\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.

--keepalive-time <seconds>
This option sets the time a connection needs to remain idle
before 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. (Added in 7.18.0)

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

--key <key>
(SSL/SSH) Private key file name. Allows you to provide your
private 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 this option is used several times, the last one will be used.

--key-type <type>
(SSL) Private key file type. Specify which type your --key
provided 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.

--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.

This option requires a library built with kerberos4 support.
This is not very common. Use -V, --version to see if your curl
supports it.

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

--krb4 <level>
(FTP) This is the former name for --krb. Do not use.

-l, --list-only
(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
message id exists on the server and what size it is.

Note: When combined with -X, --request <command>, 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 request. (Added in 7.21.5)

-L, --location
(HTTP/HTTPS) 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
authentication 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
--location-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 the request is not a plain GET
(for example POST or PUT), 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 unmodified method.

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

--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
kilobytes, '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.

--local-port <num>[-num]
Set a preferred number or range 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 setting this range
to something too narrow might cause unnecessary connection setup
failures. (Added in 7.15.2)

--location-trusted
(HTTP/HTTPS) 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).

-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
hanging for hours due to slow networks or links going down.
Since 7.32.0, this option accepts decimal values, but the actual
timeout will decrease in accuracy as the specified timeout
increases in decimal precision. See also the --connect-timeout
option.

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

--login-options <options>
Specify the login options to use during server authentication.

You can use the login options to specify protocol specific
options 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 (Added in 7.34.0).

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

--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.

(Added in 7.25.0)

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

(Added in 7.20.0)

--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.

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

--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. (Added in 7.20.0)

When performing an address verification (VRFY command), the
recipient 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
recipient should be specified using the mailing list name, such
as "Friends" or "London-Office". (Added in 7.34.0)

--max-redirs <num>
Set maximum number of redirection-followings allowed. If -L,
--location is used, this option can be used to prevent curl from
following redirections "in absurdum". By default, the limit is
set to 50 redirections. Set this option to -1 to make it
limitless.

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

--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
completes. 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
protocol (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 --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.

(Added in 7.27.0, if built against the libmetalink library.)

-n, --netrc
Makes curl scan the .netrc (_netrc on Windows) file in the
user's home directory for login name and password. This is
typically 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-readable). The environment variable "HOME" is used to find
the home directory.

A quick and very simple example of how to setup a .netrc to
allow 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

-N, --no-buffer
Disables the buffering of the output stream. In normal work
situations, 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.

--netrc-file
This option is similar to --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, only the last one
will be used. (Added in 7.21.5)

This option overrides any use of --netrc as they are mutually
exclusive. It will also abide by --netrc-optional if specified.

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

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

If you want to enable Negotiate (SPNEGO) for proxy
authentication, then use --proxy-negotiate.

This option requires a library built with GSS-API or SSPI
support. Use -V, --version to see if your curl supports GSS-
API/SSPI and 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
option aren't actually used.

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

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

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

--no-sessionid
(SSL) 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. (Added
in 7.16.0)

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

--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. (Added in 7.19.4).

--connect-to <host:port:connect-to-host:connect-to-port>
For a request to the given "host:port" pair, connect to
"connect-to-host:connect-to-port" instead. This is suitable to
direct the request at a specific server, e.g. at a specific
cluster node in a cluster of servers. This option is only used
to establish the network connection. It does NOT affect the
hostname/port that is used for TLS/SSL (e.g. SNI, certificate
verification) or for the application protocols. "host" and
"port" may be the empty string, meaning "any host/port".
"connect-to-host" and "connect-to-port" may also be the empty
string, meaning "use the request's original host/port". This
option can be used many times to add many connect rules. (Added
in 7.49.0).

--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
people 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
authentication method instead, such as Digest.

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

This option requires a library built with SSL support. Use -V,
--version to see if your curl supports NTLM.

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

--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.

-o, --output <file>
Write output to <file> instead of stdout. If you are using {} or
[] to fetch multiple documents, 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
directories dynamically. Specifying the output as '-' (a single
dash) will force the output to be done to stdout.

-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.

--oauth2-bearer
(IMAP, POP3, SMTP) 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.

--proxy-header <header>
(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
communication only like in CONNECT requests when you want a
separate header sent to the proxy to what is sent to the actual
remote host.

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

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

(Added in 7.37.0)

-p, --proxytunnel
When an HTTP proxy is used (-x, --proxy), this option will cause
non-HTTP protocols to attempt to tunnel through the proxy
instead of merely using it to do HTTP-like operations. The
tunnel approach is made with the HTTP proxy CONNECT request and
requires that the proxy allows direct connect to the remote port
number curl wants to tunnel through to.

-P, --ftp-port <address>
(FTP) Reverses the default initiator/listener roles when
connecting with FTP. This switch makes curl use active mode. In
practice, 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
i.e "eth0" to specify which interface's IP address you
want to use (Unix only)

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

host name
i.e "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.
Disable 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++.

Starting in 7.19.5, you can append ":[start]-[end]" to the right
of the address, 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.

--pass <phrase>
(SSL/SSH) 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)

--post301
(HTTP) Tells curl to respect RFC 7230/6.4.2 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
redirection. This option is meaningful only when using -L,
--location (Added in 7.17.1)

--post302
(HTTP) Tells curl to respect RFC 7230/6.4.3 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
redirection. This option is meaningful only when using -L,
--location (Added in 7.19.1)

--post303
(HTTP) Tells curl to respect RFC 7230/6.4.4 and not convert POST
requests into GET requests when following a 303 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
redirection. This option is meaningful only when using -L,
--location (Added in 7.26.0)

--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

+ Permit this protocol in addition to protocols already
permitted (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
permitted), though subject to later modification by
subsequent entries 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 relying 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.

(Added in 7.20.2)

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

Example:

--proto-default https ftp.mozilla.org
https://ftp.mozilla.org

An unknown or unsupported protocol causes error
CURLE_UNSUPPORTED_PROTOCOL.

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.
Protocols denied by --proto are not overridden by this option.
See --proto for how protocols are represented.

Example:

--proto-redir -all,http,https
Allow only HTTP and HTTPS on redirect.

By default curl will allow all protocols on redirect 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)

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

--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.

--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. (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.

--proxy-service-name <servicename>
This option allows you to change the service name for proxy
negotiation.

Examples: --proxy-negotiate proxy-name --proxy-service-name
sockd would use sockd/proxy-name. (Added in 7.43.0).

--proxy1.0 <proxyhost[: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.

--pubkey <key>
(SSH) Public key file name. Allows you to provide your public
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
generally 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, --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.

-Q, --quote <command>
(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
supported for FTP). You may specify any number of commands. If
the server returns failure for one of the commands, the entire
operation will be aborted. You must send syntactically correct
FTP commands as RFC 959 defines to FTP servers, or one of the
commands listed below to SFTP servers. This option can be used
multiple times. When speaking to an FTP server, prefix the
command with an asterisk (*) to make curl continue even if the
command fails as by default curl will stop at first failure.

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
characters. Following is the list of all supported SFTP quote
commands:

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
operand. 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
location.

mkdir directory_name
The mkdir command creates the directory named by the
directory_name operand.

pwd The pwd command returns the absolute pathname of the
current 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
operand.

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.

-r, --range <range>
(HTTP/FTP/SFTP/FILE) Retrieve a byte range (i.e a partial
document) from a 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
multipart response!

Only digit characters (0-9) are valid in the 'start' and 'stop'
fields of the 'start-stop' range syntax. If a non-digit
character is given in the range, the server's response will be
unspecified, 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.

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

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

--raw (HTTP) When used, it disables all internal HTTP decoding of
content or transfer encodings and instead makes them passed on
unaltered, raw. (Added in 7.16.2)

--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)

--resolve <host:port:address>
Provide a custom address for a specific host and port pair.
Using this, you can make the curl requests(s) use a specified
address 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.

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.

This option can be used many times to add many host names to
resolve.

(Added in 7.21.3)

--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 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.
(Added in 7.12.3)

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

--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
default 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. (Added in
7.12.3)

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

--retry-max-time <seconds>
The retry timer is reset before the first transfer attempt.
Retries 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
performing, it may take longer than this given time period. To
limit a single requests maximum time, use -m, --max-time. Set
this option to zero to not timeout retries. (Added in 7.12.3)

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

-s, --silent
Silent or quiet mode. Don't show progress meter or error
messages. Makes Curl mute. It will still output the data you
ask for, potentially even to the terminal/stdout unless you
redirect it.

--sasl-ir
Enable initial response in SASL authentication. (Added in
7.31.0)

--service-name <servicename>
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 it makes curl show an error message if it
fails.

--ssl (FTP, POP3, IMAP, SMTP) Try to use SSL/TLS for the connection.
Reverts to a non-secure connection if the server doesn't support
SSL/TLS. See also --ftp-ssl-control and --ssl-reqd for
different levels of encryption required. (Added in 7.20.0)

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
future version.

--ssl-reqd
(FTP, POP3, IMAP, SMTP) Require SSL/TLS for the connection.
Terminates the connection if the server doesn't support SSL/TLS.
(Added in 7.20.0)

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

--ssl-allow-beast
(SSL) 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
interoperability 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
(WinSSL) This option tells curl to disable certificate
revocation checks. WARNING: this option loosens the SSL
security, and by using this flag you ask for exactly that.
(Added in 7.44.0)

--socks4 <host[:port]>
Use the specified SOCKS4 proxy. If the port number is not
specified, it is assumed at port 1080. (Added in 7.15.2)

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.

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

--socks4a <host[:port]>
Use the specified SOCKS4a proxy. If the port number is not
specified, it is assumed at port 1080. (Added in 7.18.0)

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
prefix.

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

--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. (Added in 7.18.0)

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://
protocol prefix.

If this option is used several times, the last one will be used.
(This option was previously wrongly documented and used as
--socks without the number appended.)

--socks5 <host[:port]>
Use the specified SOCKS5 proxy - but resolve the host name
locally. 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.

If this option is used several times, the last one will be used.
(This option was previously wrongly documented and used as
--socks without the number appended.)

This option (as well as --socks4) does not work with IPV6, FTPS
or LDAP.

--socks5-gssapi-service <servicename>
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-nec
As part of the GSS-API negotiation a protection mode is
negotiated. 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 protection mode negotiation. (Added in 7.19.4).

--stderr <file>
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.

-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.

-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
uploaded.

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

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

or even

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

--tcp-nodelay
Turn on the TCP_NODELAY option. See the curl_easy_setopt(3) man
page for details about this option. (Added in 7.11.2)

--tcp-fastopen
Enable use of TCP Fast Open (RFC7413). (Added in 7.49.0)

--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)

--tlsauthtype <authtype>
Set TLS authentication type. Currently, the only supported
option is "SRP", for TLS-SRP (RFC 5054). If --tlsuser and
--tlspassword are specified but --tlsauthtype is not, then this
option defaults to "SRP". (Added in 7.21.4)

--tlspassword <password>
Set password for use with the TLS authentication method
specified with --tlsauthtype. Requires that --tlsuser also be
set. (Added in 7.21.4)

--tlsuser <user>
Set username for use with the TLS authentication method
specified with --tlsauthtype. Requires that --tlspassword also
be set. (Added in 7.21.4)

--tlsv1.0
(SSL) Forces curl to use TLS version 1.0 when negotiating with a
remote TLS server. (Added in 7.34.0)

--tlsv1.1
(SSL) Forces curl to use TLS version 1.1 when negotiating with a
remote TLS server. (Added in 7.34.0)

--tlsv1.2
(SSL) Forces curl to use TLS version 1.2 when negotiating with a
remote TLS server. (Added in 7.34.0)

--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 <file>
Enables a full trace dump of all incoming and outgoing data,
including 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.

This option overrides previous uses of -v, --verbose or --trace-
ascii.

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

--trace-ascii <file>
Enables a full trace dump of all incoming and outgoing data,
including 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.

This option overrides previous uses of -v, --verbose or --trace.

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

--trace-time
Prepends a time stamp to each trace or verbose line that curl
displays. (Added in 7.14.0)

--unix-socket <path>
(HTTP) Connect through this Unix domain socket, instead of using
the network. (Added in 7.40.0)

-u, --user <user:password>
Specify the user name and password to use for server
authentication. 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.

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
Kerberos V5, Negotiate, NTLM or Digest 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
:".

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

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

If you use a Windows SSPI-enabled curl binary and do either
Negotiate 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 :".

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

--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.

-v, --verbose
Be more verbose/talkative 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.

Note that 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.

This option overrides previous uses of --trace-ascii or --trace.

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

-w, --write-out <format>
Make curl display information on stdout after a completed
transfer. 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.

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

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 --remote-name or --output
option. It's most useful in combination with the
--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
response (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)

local_ip The IP address of the local end of the most
recently 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)

num_connects Number of new connects made in the recent
transfer. (Added in 7.12.3)

num_redirects Number of redirects that were followed in the
request. (Added in 7.12.3)

redirect_url When an HTTP request was made without -L to
follow redirects, this variable will show the
actual URL a redirect would take you 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)

size_download The total amount of bytes that were downloaded.

size_header The total amount of bytes of the downloaded
headers.

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
verification that was requested. 0 means the
verification was successful. (Added in 7.19.0)

time_appconnect
The time, in seconds, it took from the start
until the SSL/SSH/etc connect/handshake to the
remote host was completed. (Added in 7.19.0)

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

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

time_pretransfer
The time, in seconds, it took from the start
until the file transfer was just about to begin.
This includes all pre-transfer commands and
negotiations that are specific to the particular
protocol(s) involved.

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

time_starttransfer
The time, in seconds, it took from the start
until the first byte was just about to be
transferred. This includes time_pretransfer and
also the time the server needed to calculate the
result.

time_total The total time, in seconds, that the full
operation lasted. The time will be displayed with
millisecond resolution.

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

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

-x, --proxy <[protocol://][user:password@]proxyhost[:port]>
Use the specified proxy.

The proxy string can be specified with a protocol:// prefix to
specify alternative proxy protocols. Use socks4://, socks4a://,
socks5:// or socks5h:// to request the specific SOCKS version to
be used. No protocol specified, http:// and all others will be
treated as HTTP proxies. (The protocol support was added in curl
7.21.7)

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
transparently 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, --proxytunnel option.

User and password that might be provided in the proxy string are
URL decoded by curl. This allows you to pass in special
characters 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.

-X, --request <command>
(HTTP) Specifies a custom request method to use when
communicating 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 explanations. 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
command line options.

This option only changes the actual word used in the HTTP
request, 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 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.

--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.

-y, --speed-time <time>
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.

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.

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

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

-z, --time-cond <date expression>|<file>
(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>
instead. See the curl_getdate(3) man pages for date expression
details.

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.

-h, --help
Usage help. This lists all current command line options with a
short description.

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

-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:

IPv6 You can use IPv6 with this.

krb4 Krb4 for FTP is supported.

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

libz Automatic decompression of compressed files over HTTP is
supported.

NTLM NTLM authentication is supported.

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

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

SPNEGO SPNEGO authentication is supported.

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

IDN This curl supports IDN - international domain names.

GSS-API
GSS-API is supported.

SSPI SSPI is supported.

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

HTTP2 HTTP/2 support has been built-in.

Metalink
This curl supports Metalink (both version 3 and 4 (RFC
5854)), which describes mirrors and hashes. curl will
use mirrors for failover if there are errors (such as the
file or server not being available).

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 --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
          protocol  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>
          list  of  host names that shouldn't go through any proxy. If set
          to a asterisk '*' only, it matches all hosts.

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:

   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
   error 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
          request  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
          resolved.

   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.

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

   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.

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

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

   19     FTP couldn't  download/access  the  given  file,  the  RETR  (or
          similar) 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
          returned 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
          according 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
          instead!

   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     FTP  bad  download  resume. Couldn't continue an earlier aborted
          download.

   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
          operation.

   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
          maximum 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
          certificates.

   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

   XX     More  error  codes  will  appear  here  in  future releases. The
          existing 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

FTP

   ftp://ftp.sunet.se/pub/www/utilities/curl/

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curl(1)

NAME

SYNOPSIS

DESCRIPTION

URL

PROGRESS METER

OPTIONS

FILES

ENVIRONMENT

PROXY PROTOCOL PREFIXES

EXIT CODES

AUTHORS / CONTRIBUTORS

WWW

FTP

SEE ALSO

Opportunity

Free Software

Free Books

Education