curl offers a busload of useful tricks like proxy support, user
authentication, ftp upload, HTTP post, SSL (https:) connections, cookies, file
transfer resume and more. As you will see below, the amount of features will
make your head spin!
You can specify multiple URLs or parts of URLs by writing part sets within
braces as in:
No nesting of the sequences is supported at the moment, but you can use
several ones next to each other:
You can specify any amount of URLs on the command line. They will be fetched
in a sequential manner in the specified order.
Since curl 7.15.1 you can also specify step counter for the ranges, so that
you can get every Nth number or letter:
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 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.
However, since curl displays data to the terminal by default, 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 is not spitting out
any response data to the terminal.
- -a/--append
-
(FTP) When used in an FTP upload, this will tell curl to append to the target
file instead of overwriting it. If the file doesn't exist, it will be created.
If this option is used twice, the second one will disable append mode again.
- -A/--user-agent <agent string>
-
(HTTP) Specify the User-Agent string to send to the HTTP server. Some badly
done CGIs fail if its not 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 set more than once, the last one will be the one that's
used.
- --anyauth
-
(HTTP) Tells curl to figure out authentication method by itself, and use the
most secure one the remote site claims it supports. This is done by first
doing a request and checking the response-headers, thus 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.
If this option is used several times, the following occurrences make no
difference.
- -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 '=' letter 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 parser" 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 or the Netscape/Mozilla
cookie file format.
NOTE that the file specified with -b/--cookie is only used as
input. No cookies will be stored in the file. To store cookies, use the
-c/--cookie-jar option or you could even save the HTTP headers to a file
using -D/--dump-header!
If this option is set more than once, the last one will be the one that's
used.
- -B/--use-ascii
-
Enable ASCII transfer when using FTP or LDAP. 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.
If this option is used twice, the second one will disable ASCII usage.
- --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 and --negotiate).
If this option is used several times, the following occurrences make no
difference.
- --ciphers <list of ciphers>
-
(SSL) Specifies which ciphers to use in the connection. The list of ciphers
must be using valid ciphers. Read up on SSL cipher list details on this URL:
http://www.openssl.org/docs/apps/ciphers.html
If this option is used several times, the last one will override the others.
- --compressed
-
(HTTP) Request a compressed response using one of the algorithms libcurl
supports, and return the uncompressed document. If this option is used and
the server sends an unsupported encoding, Curl will report an error.
If this option is used several times, each occurrence will toggle it on/off.
- --connect-timeout <seconds>
-
Maximum time in seconds that you allow the connection to the server to take.
This only limits the connection phase, once curl has connected this option is
of no more use. See also the -m/--max-time option.
If this option is used several times, the last one will be used.
- -c/--cookie-jar <file name>
-
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 Netscape cookie
file format. If you set the file name to a single dash, "-", the cookies will
be written to stdout.
NOTE
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 counted 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.
- --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, try --ftp-create-dirs.
- --crlf
-
(FTP) Convert LF to CRLF in upload. Useful for MVS (OS/390).
If this option is used several times, the following occurrences make no
difference.
- -d/--data <data>
-
(HTTP) Sends the specified data in a POST request to the HTTP server, in a way
that can emulate as if a user has filled in a HTML form and pressed the submit
button. Note that the data is sent exactly as specified with no extra
processing (with all newlines cut off). The data is expected to be
"url-encoded". This will cause curl to pass the data to the server using the
content-type application/x-www-form-urlencoded. Compare to -F/--form. If
this option is used more than once on the same command line, the data pieces
specified will be merged together with a separating &-letter. 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. The
contents of the file must already be url-encoded. Multiple files can also be
specified. Posting data from a file named 'foobar' would thus be done with
--data @foobar".
To post data purely binary, you should instead use the --data-binary
option.
-d/--data is the same as --data-ascii.
If this option is used several times, the ones following the first will
append data.
- --data-ascii <data>
-
(HTTP) This is an alias for the -d/--data option.
If this option is used several times, the ones following the first will
append data.
- --data-binary <data>
-
(HTTP) This posts data in a similar manner as --data-ascii does,
although when using this option the entire context of the posted data is kept
as-is. If you want to post a binary file without the strip-newlines feature of
the --data-ascii option, this is for you.
If this option is used several times, the ones following the first will
append data.
- --digest
-
(HTTP) Enables HTTP Digest authentication. This is a authentication 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, the following occurrences make no
difference.
- --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, may not work
on all servers but enable more functionality in a better way than the
traditional PORT command.
If this option is used several times, each occurrence will toggle this on/off.
- --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.
If this option is used several times, each occurrence will toggle this on/off.
- -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 a HTTP
site sends to you. Cookies from the headers could then be read in a second
curl invoke by using the -b/--cookie option! The -c/--cookie-jar
option is however a better way to store cookies.
When used on 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.
- -e/--referer <URL>
-
(HTTP) Sends the "Referer 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.
- --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 easier allow extraction of useful information after having
run curl.
If this option is used several times, each occurrence will toggle this on/off.
- --egd-file <file>
-
(HTTPS) 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.
- -E/--cert <certificate[:password]>
-
(HTTPS)
Tells curl to use the specified certificate file when getting a file
with HTTPS. 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 certificate is the private key and the private
certificate concatenated!
If this option is used several times, the last one will be used.
- --cert-type <type>
-
(SSL) Tells curl what certificate type the provided certificate is in. PEM,
DER and ENG are recognized types.
If this option is used several times, the last one will be used.
- --cacert <CA certificate>
-
(HTTPS) 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.
curl recognizes the environment variable named 'CURL_CA_BUNDLE' if that 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 this option is used several times, the last one will be used.
- --capath <CA certificate directory>
-
(HTTPS) Tells curl to use the specified certificate directory to verify the
peer. The certificates must be in PEM format, and the directory must have been
processed using the c_rehash utility supplied with openssl. Using
--capath can allow curl to make https connections much more efficiently
than using --cacert if the --cacert file contains many CA
certificates.
If this option is used several times, the last one will be used.
- -f/--fail
-
(HTTP) Fail silently (no output at all) on server errors. This is mostly done
like this to better enable scripts etc to better deal with failed attempts. In
normal cases when a 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.
If this option is used twice, the second will again disable silent failure.
- --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 twice, the second will override the previous use.
- --ftp-create-dirs
-
(FTP) When an FTP 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.
If this option is used twice, the second will again disable directory creation.
- --ftp-method [method]
-
(FTP) Control what method curl should use to reach a file on a 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 RFC1738 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'.
- --ftp-pasv
-
(FTP) Use PASV when transferring. PASV is the internal default behavior, but
using this option can be used to override a previous --ftp-port option. (Added
in 7.11.0)
If this option is used several times, the following occurrences make no
difference.
- --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-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.
If this option is used twice, the second will again use the server's suggested
address.
- --ftp-ssl
-
(FTP) Try to use SSL/TLS for the FTP connection.
Reverts to a non-secure connection if the server doesn't support SSL/TLS.
(Added in 7.11.0)
If this option is used twice, the second will again disable this.
- --ftp-ssl-reqd
-
(FTP) Require SSL/TLS for the FTP connection.
Terminates the connection if the server doesn't support SSL/TLS.
(Added in 7.15.5)
If this option is used twice, the second will again disable this.
- -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 RFC1867. 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 letter <. 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 the file's content from stdin instead of a file, use - where the file
name should've been. This goes for both @ and < constructs.
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" url.com
or
curl -F "name=daniel;type=text/foo" url.com
You can also explicitly change the name field of an file upload part by
setting filename=, like this:
curl -F "file=@localfile;filename=nameinpost" url.com
See further examples and details in the MANUAL.
This option can be used multiple times.
- --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 or
--data-binary to be used in a 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, the following occurrences make no
difference.
- -h/--help
-
Usage help.
- -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 knowing perfectly well what you're doing. Replacing an
internal header with one without content on the right side of the colon will
prevent that header from appearing.
curl will make sure that each header you add/replace get 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.
- --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...
If this option is used twice, the second will again disable header include.
- --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.
- -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 a FTP or FILE file, curl displays the file size and last modification
time only.
If this option is used twice, the second will again disable header only.
- -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.
If this option is used several times, each occurrence will toggle this on/off.
- -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" to fail unless -k/--insecure is used.
If this option is used twice, the second time will again disable it.
- --key <key>
-
(SSL) Private key file name. Allows you to provide your private key in this
separate file.
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 this option is used several times, the last one will be used.
- --krb4 <level>
-
(FTP) Enable kerberos4 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 that the library was 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.
- -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. If the parameter is
to contain white spaces, the parameter must be enclosed within quotes. If the
first column of a config line is a '#' character, the rest of the line will be
treated as a comment.
Specify the filename 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/"
This option can be used multiple times.
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 executable curl is placed. On unix-like systems, it will
simply try to load .curlrc from the determined home dir.
- --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 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. Examples: 200K, 3m and 1G.
If you are also using the -Y/--speed-limit option, that option will take
precedence and might cripple the rate-limiting slightly, to help keeping the
speed-limit logic working.
If this option is used several times, the last one will be used.
- -l/--list-only
-
(FTP)
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.
If this option is used twice, the second will again disable list only.
- --local-port <num>[-num]
-
Set a prefered number or range of local port numbers to use for the
connection(s). Note that port numbers by nature is 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)
- -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.
If this option is used twice, the second will again disable location following.
- --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 do a site to which
you'll send your authentication info (which is plaintext in the case of HTTP
Basic authentication).
If this option is used twice, the second will again disable location following.
- --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.
- -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.
- -M/--manual
-
Manual. Display the huge help text.
- -n/--netrc
-
Makes curl scan the .netrc 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(4)
or
ftp(1)
for details on the file format. Curl will not complain if that file
hasn't the right permissions (it should not be world nor 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
If this option is used twice, the second will again disable netrc usage.
- --netrc-optional
-
Very similar to --netrc, but this option makes the .netrc usage
optional and not mandatory as the --netrc 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 methods. For more information see IETF draft
draft-brezak-spnego-http-04.txt.
This option requires that the library was 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 actually used.
If this option is used several times, the following occurrences make no
difference.
- -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.
If this option is used twice, the second will again switch on buffering.
- --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, reversed 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 that the library was built with SSL support. Use
-V/--version to see if your curl supports NTLM.
If this option is used several times, the following occurrences make no
difference.
- -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}.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 you have number of URLs.
See also the --create-dirs option to create the local directories
dynamically.
- -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.
You may use this option as many times as you have number of URLs.
- --pass <phrase>
-
(SSL) Pass phrase for the private key
If this option is used several times, the last one will be used.
- --proxy-anyauth
-
Tells curl to pick a suitable authentication method when communicating with
the given proxy. This will cause an extra request/response round-trip. (Added
in 7.13.2)
If this option is used twice, the second will again disable the proxy use-any
authentication.
- --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.
If this option is used twice, the second will again disable proxy HTTP Basic
authentication.
- --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.
If this option is used twice, the second will again disable proxy HTTP Digest.
- --proxy-ntlm
-
Tells curl to use HTTP NTLM authentication when communicating with the given
proxy. Use --ntlm for enabling NTLM with a remote host.
If this option is used twice, the second will again disable proxy HTTP NTLM.
- -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.
If this option is used twice, the second will again disable proxy tunnel.
- -P/--ftp-port <address>
-
(FTP) Reverses the initiator/listener roles when connecting with ftp. This
switch makes Curl use the PORT command instead of PASV. In practice, PORT
tells the server to connect to the client's specified address and port, while
PASV asks the server for an ip address and port 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 exact IP number
- host name
-
i.e "my.host.domain" to specify 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++.
- -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) Send an arbitrary command to the remote FTP server. Quote commands are
sent BEFORE the transfer is taking place (just after the initial PWD command
to be exact). To make commands take place after a successful transfer, prefix
them with a dash '-'. To make commands get sent after libcurl has changed
working directory, just before the transfer command(s), prefix the command
with '+'. You may specify any amount 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 RFC959 defines.
This option can be used multiple times.
- --random-file <file>
-
(HTTPS) 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.
- -r/--range <range>
-
(HTTP/FTP)
Retrieve a byte range (i.e a partial document) from a HTTP/1.1 or FTP
server. 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 bytes ranges(*)(H)
(*) = NOTE that this will cause the server to reply with a multipart
response!
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 range downloads only support the simple syntax 'start-stop' (optionally
with one of the numbers omitted). It depends on the non-RFC command SIZE.
If this option is used several times, the last one will be used.
- -R/--remote-time
-
When used, this will make libcurl attempt to figure out the timestamp of the
remote file, and if that is available make the local file get that same
timestamp.
If this option is used twice, the second time disables this again.
- --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 5xx 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 multiple times, the last occurrence decide the amount.
- --retry-delay <seconds>
-
Make curl sleep this amount of time between 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 multiple times, the last occurrence decide the amount.
- --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 multiple times, the last occurrence decide the amount.
- -s/--silent
-
Silent mode. Don't show progress meter or error messages. Makes
Curl mute.
If this option is used twice, the second will again disable silent mode.
- -S/--show-error
-
When used with -s it makes curl show error message if it fails.
If this option is used twice, the second will again disable show error.
- --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.
If this option is used several times, the last one will be used.
- --socks5 <host[:port]>
-
Use the specified SOCKS5 proxy. If the port number is not specified, it is
assumed at port 1080. (Added in 7.11.1)
This option overrides any previous use of -x/--proxy, as they are
mutually exclusive.
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.)
- --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. This option has no point when
you're using a shell with decent redirecting capabilities.
If this option is used several times, the last one will be used.
- --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)
If this option is used several times, each occurrence toggles this on/off.
- -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 a http(s) server, the PUT command will be used.
Use the file name "-" (a single dash) to use stdin instead of a given file.
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/
- --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.
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.
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)
If this option is used several times, each occurrence will toggle it on/off.
- -u/--user <user:password>
-
Specify user and password to use for server authentication. Overrides
-n/--netrc and --netrc-optional.
If you use an SSPI-enabled curl binary and do NTLM autentication, 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 user and password to use for proxy authentication.
If you use an SSPI-enabled curl binary and do NTLM autentication, 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.
- --url <URL>
-
Specify a URL to fetch. This option is mostly handy when you want to specify
URL(s) in a config file.
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
-
Makes the fetching more verbose/talkative. Mostly usable for debugging. Lines
starting with '>' means "header data" sent by curl, '<' means "header data"
received by curl that is hidden in normal cases and lines starting with '*'
means additional info provided by curl.
Note that if you only want HTTP headers in the output, -i/--include
might be option you're looking for.
If you think this option still doesn't give you enough details, consider using
--trace or --trace-ascii instead.
If this option is used twice, the second will again disable verbose.
- -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
-
HTTPS and FTPS are supported.
- libz
-
Automatic decompression of compressed files over HTTP is supported.
- NTLM
-
NTLM authentication is supported.
- GSS-Negotiate
-
Negotiate 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.
- 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.
- -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
like %{variable_name} and to output a normal % you just write them like
%%. You can output a newline by using \n, a carriage return with \r and a tab
space with \t.
NOTE:
The %-letter is a special letter in the win32-environment, where all
occurrences of % must be doubled when using this option.
Available variables are at this point:
-
- url_effective
-
The URL that was fetched last. This is mostly meaningful if you've told curl
to follow location: headers.
- http_code
-
The numerical code that was found in the last retrieved HTTP(S) page.
- 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)
- time_total
-
The total time, in seconds, that the full operation lasted. The time will be
displayed with millisecond resolution.
- time_namelookup
-
The time, in seconds, it took from the start until the name resolving was
completed.
- time_connect
-
The time, in seconds, it took from the start until the connect to the remote
host (or proxy) was completed.
- time_pretransfer
-
The time, in seconds, it took from the start until the file transfer is 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 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 is just about
to be transferred. This includes time_pretransfer and also the time the
server needs to calculate the result.
- size_download
-
The total amount of bytes that were downloaded.
- size_upload
-
The total amount of bytes that were uploaded.
- 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.
- speed_download
-
The average download speed that curl measured for the complete download.
- speed_upload
-
The average upload speed that curl measured for the complete upload.
- content_type
-
The Content-Type of the requested document, if there was any.
- 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)
- ftp_entry_path
-
The initial path libcurl ended up in when logging on to the remote FTP
server. (Added in 7.15.4)
If this option is used several times, the last one will be used.
- -x/--proxy <proxyhost[:port]>
-
Use specified HTTP proxy. If the port number is not specified, it is assumed
at port 1080.
This option overrides existing environment variables that sets proxy to
use. If there's an environment variable setting a proxy, you can set proxy to
"" to override it.
Note that all operations that are performed over a 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 done with the -p/--proxytunnel option.
Starting with 7.14.1, the proxy host can be specified the exact same way as
the proxy environment variables, include protocol prefix (http://) and
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 will be used instead of the method
otherwise used (which defaults to GET). Read the HTTP 1.1 specification for
details and explanations.
(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.
- -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>
-
(HTTP) 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
tries to get the time from a given file name 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.
- --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.
- -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
-
(HTTPS)
Forces curl to use TSL version 1 when negotiating with a remote TLS server.
- -2/--sslv2
-
(HTTPS)
Forces curl to use SSL version 2 when negotiating with a remote SSL server.
- -3/--sslv3
-
(HTTPS)
Forces curl to use SSL version 3 when negotiating with a remote SSL server.
- --3p-quote
-
(FTP) Specify arbitrary commands to send to the source server. See the
-Q/--quote option for details. (Added in 7.13.0)
- --3p-url
-
(FTP) Activates a FTP 3rd party transfer. Specifies the source URL to get a
file from, while the "normal" URL will be used as target URL, the file that
will be written/created.
Note that not all FTP server allow 3rd party transfers. (Added in 7.13.0)
- --3p-user
-
(FTP) Specify user:password for the source URL transfer. (Added in 7.13.0)
- -4/--ipv4
-
If libcurl is capable of resolving an address to multiple IP versions (which
it is if it is ipv6-capable), this option tells libcurl to resolve names to
IPv4 addresses only.
- -6/--ipv6
-
If libcurl is capable of resolving an address to multiple IP versions (which
it is if it is ipv6-capable), this option tells libcurl to resolve names to
IPv6 addresses only.
- -#/--progress-bar
-
Make curl display progress information as a progress bar instead of the
default statistics.
If this option is used twice, the second will again disable the progress bar.
