curl(1) Curl Manual 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, 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.numericals.com/file[1-100].txt
ftp://ftp.numericals.com/file[001-100].txt (with leading zeros)
ftp://ftp.letters.com/file[a-z].txt
Nested sequences are not supported, but you can use several ones next to each other:
http://any.org/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://www.numericals.com/file[1-100:10].txt
http://www.letters.com/file[a-z:2].txt
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.
OPTIONS
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.
-0, --http1.0
(HTTP) Forces curl to issue its requests using HTTP 1.0 instead of using its internally preferred: HTTP
1.1.
-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 back‐
end 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.
-3, --sslv3
(SSL) Forces curl to use SSL version 3 when negotiating with a remote SSL server.
-4, --ipv4
If curl is capable of resolving an address to multiple IP versions (which it is if it is IPv6-capable),
this option tells curl to resolve names to IPv4 addresses only.
-6, --ipv6
If curl is capable of resolving an address to multiple IP versions (which it is if it is IPv6-capable),
this option tells curl to resolve names to IPv6 addresses only.
-a, --append
(FTP/SFTP) When used in an upload, this will tell curl to append to the target file instead of over‐
writing it. If the file doesn't exist, it will be created. Note that this flag is ignored by some SSH
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 authentica‐
tion 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.
file using -D, --dump-header!
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. 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).
-c, --cookie-jar <file name>
(HTTP) Specify to which file you want curl to write all cookies after a completed operation. Curl
writes all cookies previously read from a specified file as well as all cookies received from remote
server(s). If no cookies are known, no file will be written. The file will be written using the Net‐
scape cookie file format. If you set the file name to a single dash, "-", the cookies will be written
to stdout.
This command line option will activate the cookie engine that makes curl record and use cookies.
Another way to activate it is to use the -b, --cookie option.
If the cookie jar can't be created or written to, the whole curl operation won't fail or even report an
error clearly. Using -v will get a warning displayed, but that is the only visible feedback you get
about this possibly lethal situation.
If this option is used several times, the last specified file name will be used.
-C, --continue-at <offset>
Continue/Resume a previous file transfer at the given offset. The given offset is the exact number of
bytes that will be skipped, counting from the beginning of the source file before it is transferred to
the destination. If used with uploads, the FTP server command SIZE will not be used by curl.
Use "-C -" to tell curl to automatically find out where/how to resume the transfer. It then uses the
given output/input files to figure that out.
If this option is used several times, the last one will be used.
--ciphers <list of ciphers>
(SSL) Specifies which ciphers to use in the connection. The list of ciphers must specify valid ciphers.
Read up on SSL cipher list details on this URL: http://www.openssl.org/docs/apps/ciphers.html
NSS ciphers are done differently than OpenSSL and GnuTLS. The full list of NSS ciphers is in the NSSCi‐
pherSuite entry at this URL: http://git.fedora‐
hosted.org/cgit/mod_nss.git/plain/docs/mod_nss.html#Directives
If this option is used several times, the last one will be used.
--compressed
(HTTP) Request a compressed response using one of the algorithms curl supports, and save the uncom‐
pressed document. If this option is used and the server sends an unsupported encoding, curl will
report an error.
To create remote directories when using FTP or SFTP, try --ftp-create-dirs.
--crlf (FTP) Convert LF to CRLF in upload. Useful for MVS (OS/390).
--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. 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 gener‐
ate 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. The contents of the file must already be URL-encoded. Mul‐
tiple files can also be specified. Posting data from a file named 'foobar' would thus be done with
--data @foobar.
-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 however 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 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.
=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=urlen‐
coded-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 nor‐
mally 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 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 PEM format. 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 private 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 cer‐
tificate 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 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 ran‐
dom engine for SSL connections. See also the --random-file option.
--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 multi‐
ple 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.
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
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 your password file to the server, where 'password' is the name of the form-field to
which /etc/passwd will be the input:
curl -F password=@/etc/passwd www.mypasswords.com
To read content from stdin instead of a file, use - as the filename. This goes for both @ and < con‐
structs.
You can also tell curl what Content-Type to use by using 'type=', in a manner similar to:
curl -F "[email protected];type=text/html" url.com
or
curl -F "name=daniel;type=text/foo" url.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" url.com
If filename/path contains ',' or ';', it must be quoted by double-quotes like:
curl -F "file=@\"localfile\";filename=\"nameinpost\"" url.com
or
curl -F 'file=@"localfile";filename="nameinpost"' url.com
Note that if a filename/path is quoted by double-quotes, any double-quote or backslash within the file‐
name 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.
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 trans‐
action. 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 shut‐
down, 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.
--form-string <name=string>
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 use when getting a web page. 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 know‐
ing 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.
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 check‐
sum 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
(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.
-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 http://www.netscape.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 "ses‐
sion cookies". This will basically have the same effect as if a new session is started. Typical
-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 white‐
space, colon, the equals sign or any combination thereof (however, the preferred separator is the
equals sign). 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 back‐
slash 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 con‐
fig 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 = "http://curl.haxx.se/docs/"
Long option names can optionally be given in the config file without the initial double dashes.
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 = "curl.haxx.se"
output = "curlhere.html"
user-agent = "superagent/1.0"
# and fetch another URL too
url = "curl.haxx.se/docs/manpage.html"
-O
referer = "http://nowhereatall.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
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 or GSSAPI (GSS-Negotiate) 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.
-l, --list-only
(FTP) When listing an FTP directory, this switch forces a name-only view. Especially useful if you
want to machine-parse the contents of an FTP directory since the normal directory view doesn't use a
standard look or format.
This option causes an FTP NLST command to be sent. Some FTP servers list only files in their response
to NLST; they do not include subdirectories and symbolic links.
-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.
--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. This feature is useful if you have a limited
pipe and you'd like your transfer not to use your entire bandwidth.
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. Exam‐
ples: 200K, 3m and 1G.
The given rate is the average speed counted during the entire transfer. It means that curl might use
higher transfer speeds in short bursts, but over time it uses no more than the given rate.
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.
tion).
-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. See also the --connect-
timeout option.
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 that the given mail should get sent to. This option can be used multi‐
ple times to specify many recipients.
(Added in 7.20.0)
--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://):
tion. See netrc(4) or 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 necessar‐
ily 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 buffer‐
ing.
--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 GSS-Negotiate authentication. The GSS-Negotiate method was designed by Microsoft and is
used in their web applications. It is primarily meant as a support for Kerberos5 authentication but may
be also used along with another authentication method. For more information see IETF draft draft-
brezak-spnego-http-04.txt.
If you want to enable Negotiate for your proxy authentication, then use --proxy-negotiate.
This option requires a library built with GSSAPI support. This is not very common. Use -V, --version to
see if your version supports GSS-Negotiate.
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 actu‐
ally 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.
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).
--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 imple‐
mented in curl based on their efforts. This kind of behavior should not be endorsed, you should encour‐
age 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.
-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 cur‐
rent string for the URL being fetched. Like in:
curl http://{one,two}.site.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.
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 remote file name to use for saving is extracted from the given URL, nothing else.
Consequentially, the file will be saved in the current working directory. If you want the file saved in
a different directory, make sure you change current working directory before you invoke curl with the
-O, --remote-name flag!
You may use this option as many times as the number of URLs you have.
-p, --proxytunnel
When an HTTP proxy is used (-x, --proxy), this option will cause non-HTTP protocols to attempt to tun‐
nel 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
- 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. Dis‐
able 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.
--post301
(HTTP) Tells curl to respect RFC 2616/10.3.2 and not convert POST requests into GET requests when fol‐
lowing a 301 redirection. The non-RFC behaviour is ubiquitous in web browsers, so curl does the conver‐
sion 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 2616/10.3.2 and not convert POST requests into GET requests when fol‐
lowing a 302 redirection. The non-RFC behaviour is ubiquitous in web browsers, so curl does the conver‐
sion 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 2616/10.3.2 and not convert POST requests into GET requests when fol‐
lowing a 303 redirection. The non-RFC behaviour is ubiquitous in web browsers, so curl does the conver‐
sion 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 use the listed protocols for its initial retrieval. Protocols are evaluated left to
right, are comma separated, and are each a protocol name or 'all', optionally prefixed by zero or more
modifiers. Available modifiers are:
+ Permit this protocol in addition to protocols already 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 modifica‐
tion 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
(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 prox‐
ies.
--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 authentication when communicating with the given proxy. Use --negoti‐
ate for enabling HTTP Negotiate 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.
--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 CON‐
NECT 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 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 syntacti‐
cally 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 com‐
mand with an asterisk (*) to make curl continue even if the command fails as by default curl will stop
at first failure.
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(*)(H)
500-700,600-799
specifies 300 bytes from offset 500(H)
100-199,500-599
specifies two separate 100-byte ranges(*)(H)
(*) = 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
(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.
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). Tran‐
sient 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 algo‐
rithm. 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 request´s 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.
doesn't support SSL/TLS. (Added in 7.20.0)
This option was formerly known as --ftp-ssl-reqd (added in 7.15.5). That option name can still be used
but will be removed in a future version.
--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 work-arounds known to cause interoperabil‐
ity 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)
--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 speci‐
fied, it is assumed at port 1080.
This option overrides any previous use of -x, --proxy, as they are mutually exclusive.
Since 7.21.7, this option is superfluous since you can specify a socks5 proxy with -x, --proxy using a
socks5:// protocol prefix.
--socks5-gssapi-nec
As part of the gssapi 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 read‐
ing 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.uploadtothissite.com
or even
curl -T "img[1-1000].png" ftp://ftp.picturemania.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)
--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)
--tlsauthtype <authtype>
--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.
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 just give the user name (without entering a colon) curl will prompt for a password.
If you use an SSPI-enabled curl binary and do NTLM authentication, you can force curl to pick up the
user name and password from your environment by simply 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.
-v, --verbose
Makes the fetching more verbose/talkative. Mostly useful for debugging. 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>
Defines what to display on stdout after a completed and successful operation. The format is a string
that may contain plain text mixed with any number of variables. The string can be specified as
"string", to get read from a particular file you specify it "@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 combi‐
nation with the --remote-header-name option. (Added in 7.25.1)
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)
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)
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 sec‐
ond.
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 ver‐
ification 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 cal‐
culate 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 HTTP proxy. If the port number is not specified, it is assumed at port 1080.
This option overrides existing environment variables that set the proxy to use. If there's an environ‐
ment variable setting a proxy, you can set proxy to "" to override it.
be used. No protocol specified, http:// and all others will be treated as HTTP proxies.
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 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.
(FTP) Specifies a custom FTP command to use instead of LIST when doing file lists with FTP.
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 extened 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.
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 HTTPS and FTPS are supported.
libz Automatic decompression of compressed files over HTTP is supported.
NTLM NTLM authentication is supported.
GSS-Negotiate
Negotiate authentication and krb5 for FTP 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.
SPNEGO SPNEGO Negotiate authentication is supported.
Largefile
This curl supports transfers of large files, files larger than 2GB.
IDN This curl supports IDN - international domain names.
SSPI SSPI is supported. If you use NTLM and set a blank user name, curl will authenticate with your
current user and password.
TLS-SRP
SRP (Secure Remote Password) authentication is supported for TLS.
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.
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 FTP 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.
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.
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
XX More error codes will appear here in future releases. The existing ones are meant to never change.
Curl 7.27.0 27 July 2012 curl(1)
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