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[libcurl.git] / curl.1

.\" You can view this file with:
.\" nroff -man curl.1
.\" Written by Daniel Stenberg
.\"
.TH curl 1 "8 November 1999" "Curl 6.3" "Curl Manual"
.SH NAME
curl \- get a URL with FTP, TELNET, LDAP, GOPHER, DICT, FILE, HTTP or
HTTPS syntax.
.SH SYNOPSIS
.B curl [options]
.I url
.SH DESCRIPTION
.B curl
is a client to get documents/files from servers, using any of the
supported protocols. The command is designed to work without user
interaction or any kind of interactivity.

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.
.SH URL
The URL syntax is protocol dependent. You'll find a detailed description in
RFC 2396.

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

It is possible to specify up to 9 sets or series for a URL, but no nesting is
supported at the moment:

 http://www.any.org/archive[1996-1999]/volume[1-4]part{a,b,c,index}.html
.SH OPTIONS
.IP "-a/--append"
(FTP)
When used in a 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.
.IP "-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 flag of course.
.IP "-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 cookie file
format.
.IP "-B/--ftp-ascii"
(FTP/LDAP)
Use ASCII transfer when getting an FTP file or LDAP info. For FTP, this can
also be enforced by using an URL that ends with ";type=A".
.IP "-c/--continue"
Continue/Resume a previous file transfer. This instructs curl to
continue appending data on the file where it was previously left,
possibly because of a broken connection to the server. There must be
a named physical file to append to for this to work.
Note: Upload resume is depening on a command named SIZE not always
present in all ftp servers! Upload resume is for FTP only.
HTTP resume is only possible with HTTP/1.1 or later servers.
.IP "-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 transfered
to the destination.
If used with uploads, the ftp server command SIZE will not be used by
curl. Upload resume is for FTP only.
HTTP resume is only possible with HTTP/1.1 or later servers.
.IP "-d/--data <data>"
(HTTP)
Sends the specified data in a POST request to the HTTP server. Note
that the data is sent exactly as specified with no extra processing.
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.

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.
.IP "-D/--dump-header <file>"
(HTTP/FTP)
Write the HTTP headers to this file. Write the FTP file info to this
file if -I/--head is used.
.IP "-e/--referer <URL>"
(HTTP)
Sends the "Referer Page" information to the HTTP server. Some badly
done CGIs fail if it's not set. This can also be set with the -H/--header
flag of course.
.IP "-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!
.IP "-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 a HTML document stating so (which often also
describes why and more). This flag will prevent curl from
outputting that and fail silently instead.
.IP "-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
read from a file, prefix the file name with an @ sign. 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:

.B curl
-F password=@/etc/passwd www.mypasswords.com

To read the file's content from stdin insted of a file, use - where the file
name should've been.
.IP "-h/--help"
Usage help.
.IP "-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.
.IP "-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...
.IP "-I/--head"
(HTTP/FTP)
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 file, curl displays the file size only.
.IP "-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. 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.
.IP "-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.
.IP "-L/--location"
(HTTP/HTTPS)
If the server reports that the requested page has a different location
(indicated with the header line Location:) this flag will let curl
attempt to reattempt the get on the new place. If used together with
-i or -I, headers from all requested pages will be shown.
.IP "-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.
This doesn't work properly in win32 systems.
.IP "-M/--manual"
Manual. Display the huge help text.
.IP "-n/--netrc"
Makes curl scan the
.I .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
.BR netrc(4)
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
.I .netrc
to allow curl to ftp to the machine host.domain.com with user name
'myself' and password 'secret' should look similar to:

.B "machine host.domain.com user myself password secret"
.IP "-o/--output <file>"
Write output to <file> instead of stdout. If you are using {} or [] to fetch
multiple documents, you can use #<num> 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"
.IP "-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.)
.IP "-P/--ftpport <address>"
(FTP)
Reverses the initiator/listenor 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
 "-"       - (any single-letter string) to make it pick the machine's default
.IP "-q"
If used as the first parameter on the command line, the
.I $HOME/.curlrc
file will not be read and used as a config file.
.IP "-Q/--quote <comand>"
(FTP) Send an arbitrary command to the remote FTP server, by using the QUOTE
command of the server. Not all servers support this command, and the set of
QUOTE commands are server specific!
.IP "-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.
.IP "-s/--silent"
Silent mode. Don't show progress meter or error messages.  Makes
Curl mute.
.IP "-S/--show-error"
When used with -s it makes curl show error message if it fails.
.IP "-t/--upload"
Transfer the stdin data to the specified file. Curl will read
everything from stdin until EOF and store with the supplied name. If
this is used on a http(s) server, the PUT command will be used.
.IP "-T/--upload-file <file>"
Like -t, but this transfers the specified local file. 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.
.IP "-u/--user <user:password>"
Specify user and password to use when fetching. See README.curl for detailed
examples of how to use this. If no password is specified, curl will
ask for it interactively.
.IP "-U/--proxy-user <user:password>"
Specify user and password to use for Proxy authentication. If no
password is specified, curl will ask for it interactively.
.IP "-v/--verbose"
Makes the fetching more verbose/talkative. Mostly usable for
debugging. Lines starting with '>' means data sent by curl, '<'
means data received by curl that is hidden in normal cases and lines
starting with '*' means additional info provided by curl.
.IP "-V/--version"
Displays the full version of curl, libcurl and other 3rd party libraries
linked with the executable.
.IP "-x/--proxy <proxyhost[:port]>"
Use specified proxy. If the port number is not specified, it is assumed at
port 1080.
.IP "-X/--request <command>"
(HTTP)
Specifies a custom request to use when communicating with the HTTP server.
The specified request will be used instead of the standard 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.
.IP "-y/--speed-time <speed>"
Speed Limit. 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.
.IP "-Y/--speed-limit <time>"
Speed 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.
.IP "-z/--time-cond <date expression>"
(HTTP)
Request to get 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
.BR "GNU date(1)"
man page 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.
.IP "-3/--sslv3"
(HTTPS)
Forces curl to use SSL version 3 when negotiating with a remote SSL server.
.IP "-2/--sslv2"
(HTTPS)
Forces curl to use SSL version 2 when negotiating with a remote SSL server.
.IP "-#/--progress-bar"
Make curl display progress information as a progress bar instead of the
default statistics.
.IP "--crlf"
(FTP) Convert LF to CRLF in upload. Useful for MVS (OS/390).
.IP "--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.
.SH FILES
.I ~/.curlrc
.RS
Default config file.

.SH ENVIRONMENT
.IP "HTTP_PROXY [protocol://]<host>[:port]"
Sets proxy server to use for HTTP.
.IP "HTTPS_PROXY [protocol://]<host>[:port]"
Sets proxy server to use for HTTPS.
.IP "FTP_PROXY [protocol://]<host>[:port]"
Sets proxy server to use for FTP.
.IP "GOPHER_PROXY [protocol://]<host>[:port]"
Sets proxy server to use for GOPHER.
.IP "ALL_PROXY [protocol://]<host>[:port]"
Sets proxy server to use if no protocol-specific proxy is set.
.IP "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.
.IP "COLUMNS <integer>"
The width of the terminal.  This variable only affects curl when the
--progress-bar option is used.
.SH DIAGNOSTICS
There exists a bunch of different error messages that may appear during
bad conditions. They're all pretty verbose and descriptive and therefore
you won't find any closer description of them here.
.SH BUGS
If you do find any (or have other suggestions), mail Daniel Stenberg
<Daniel.Stenberg@haxx.nu>.
.SH AUTHORS / CONTRIBUTORS
 - Daniel Stenberg <Daniel.Stenberg@haxx.nu>
 - Rafael Sagula <sagula@inf.ufrgs.br>
 - Sampo Kellomaki <sampo@iki.fi>
 - Linas Vepstas <linas@linas.org>
 - Bjorn Reese <breese@mail1.stofanet.dk>
 - Johan Anderson <johan@homemail.com>
 - Kjell Ericson <Kjell.Ericson@sth.frontec.se>
 - Troy Engel <tengel@sonic.net>
 - Ryan Nelson <ryan@inch.com>
 - Bjorn Stenberg <Bjorn.Stenberg@sth.frontec.se>
 - Angus Mackay <amackay@gus.ml.org>
 - Eric Young <eay@cryptsoft.com>
 - Simon Dick <simond@totally.irrelevant.org>
 - Oren Tirosh <oren@monty.hishome.net>
 - Steven G. Johnson <stevenj@alum.mit.edu>
 - Gilbert Ramirez Jr. <gram@verdict.uthscsa.edu>
 - Andrés García <ornalux@redestb.es>
 - Douglas E. Wegscheid <wegscd@whirlpool.com>
 - Mark Butler <butlerm@xmission.com>
 - Eric Thelin <eric@generation-i.com>
 - Marc Boucher <marc@mbsi.ca>
 - Greg Onufer <Greg.Onufer@Eng.Sun.COM>
 - Doug Kaufman <dkaufman@rahul.net>
 - David Eriksson <david@2good.com>
 - Ralph Beckmann <rabe@uni-paderborn.de>
 - T. Yamada <tai@imasy.or.jp>
 - Lars J. Aas <larsa@sim.no>
 - Jörn Hartroth <Joern.Hartroth@telekom.de>
 - Matthew Clarke <clamat@van.maves.ca>
 - Linus Nielsen <Linus.Nielsen@haxx.nu>
 - Felix von Leitner <felix@convergence.de>
 - Dan Zitter <dzitter@zitter.net>
 - Jongki Suwandi <Jongki.Suwandi@eng.sun.com>
 - Chris Maltby <chris@aurema.com>
.SH WWW
http://curl.haxx.nu
.SH FTP
ftp://ftp.sunet.se/pub/www/utilities/curl/
.SH "SEE ALSO"
.BR ftp (1),
.BR wget (1),
.BR snarf (1)