path: root/docs/curl.1

.\" You can view this file with:
.\" nroff -man curl.1
.\" Written by Daniel Stenberg
.\"
.TH curl 1 "1 August 2000" "Curl 7.0" "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.

.B NOTE
that the file specified with -b/--cookie is only used as input. No cookies
will be stored in the file. To store cookies, save the HTTP headers to a file
using -D/--dump-header!
.IP "-B/--use-ascii"
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". This option causes
data sent to stdout to be in text mode for win32 systems.
.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.

This option is handy to use when you want to store the cookies that a HTTP
site sends to you. The cookies could then be read in a second curl invoke by
using the -b/--cookie option!
.IP "-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
.I -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.
.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 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:

.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. This goes for both @ and < constructs.
.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. Replacing an
internal header with one without content on the right side of the colon will
prevent that header from appearing.
.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. If this flag is used when
making a HTTP POST, curl will automatically switch to GET after the initial
POST has been done.
.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 fully 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 login myself password secret"
.IP "-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.
.IP "-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"
.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/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:
.RS
.TP 12
.B interface
i.e "eth0" to specify which interface's IP address you want to use  (Unix only)
.TP
.B "IP address"
i.e "192.168.10.1" to specify exact IP number
.TP
.B "host name"
i.e "my.host.domain" to specify machine
.TP
.B "-"
(any single-letter string) to make it pick the machine's default
.RE
.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! Quote commands are sent BEFORE the
transfer is taking place. To make commands take place after a successful
transfer, prefix them with a dash '-'. You may specify any amount of commands
to be run before and after the transfer. If the server returns failure for one
of the commands, the entire operation will be aborted.
.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.
.RS
.TP 10
.B 0-499
specifies the first 500 bytes
.TP
.B 500-999
specifies the second 500 bytes
.TP
.B -500
specifies the last 500 bytes
.TP
.B 9500
specifies the bytes from offset 9500 and forward
.TP
.B 0-0,-1
specifies the first and last byte only(*)(H)
.TP
.B 500-700,600-799
specifies 300 bytes from offset 500(H)
.TP
.B 100-199,500-599
specifies two separate 100 bytes ranges(*)(H)
.RE

(*) = 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 "-w/--write-out <format>"
Defines what to display 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 carrige return with \\r and a tab
space with \\t.

.B 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:
.RS
.TP 15
.B url_effective
The URL that was fetched last. This is mostly meaningful if you've told curl
to follow location: headers.
.TP
.B http_code
The numerical code that was found in the last retrieved HTTP(S) page.
.TP
.B time_total
The total time, in seconds, that the full operation lasted. The time will be
displayed with millisecond resolution.
.TP
.B time_namelookup
The time, in seconds, it took from the start until the name resolving was
completed.
.TP
.B time_connect
The time, in seconds, it took from the start until the connect to the remote
host (or proxy) was completed.
.TP
.B 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.
.TP
.B size_download
The total amount of bytes that were downloaded.
.TP
.B size_upload
The total amount of bytes that were uploaded.
.TP
.B speed_download
The average download speed that curl measured for the complete download.
.TP
.B speed_upload
The average upload speed that curl measured for the complete download.
.RE
.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 <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 "-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.
.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)"
or
.BR "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.
.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 EXIT CODES
There exists 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:
.IP 1
Unsupported protocol. This build of curl has no support for this protocol.
.IP 2
Failed to initialize.
.IP 3
URL malformat. The syntax was not correct.
.IP 4
URL user malformatted. The user-part of the URL syntax was not correct.
.IP 5
Couldn't resolve proxy. The given proxy host could not be resolved.
.IP 6
Couldn't resolve host. The given remote host was not resolved.
.IP 7
Failed to connect to host.
.IP 8
FTP weird server reply. The server sent data curl couldn't parse.
.IP 9
FTP access denied. The server denied login.
.IP 10
FTP user/password incorrect. Either one or both were not accepted by the
server.
.IP 11
FTP weird PASS reply. Curl couldn't parse the reply sent to the PASS request.
.IP 12
FTP weird USER reply. Curl couldn't parse the reply sent to the USER request.
.IP 13
FTP weird PASV reply, Curl couldn't parse the reply sent to the PASV request.
.IP 14
FTP weird 227 formay. Curl couldn't parse the 227-line the server sent.
.IP 15
FTP can't get host. Couldn't resolve the host IP we got in the 227-line.
.IP 16
FTP can't reconnect. Couldn't connect to the host we got in the 227-line.
.IP 17
FTP couldn't set binary. Couldn't change transfer method to binary.
.IP 18
Partial file. Only a part of the file was transfered.
.IP 19
FTP couldn't RETR file. The RETR command failed.
.IP 20
FTP write error. The transfer was reported bad by the server.
.IP 21
FTP quote error. A quote command returned error from the server.
.IP 22
HTTP not found. The requested page was not found. This return code only
appears if --fail is used.
.IP 23
Write error. Curl couldn't write data to a local filesystem or similar.
.IP 24
Malformat user. User name badly specified.
.IP 25
FTP couldn't STOR file. The server denied the STOR operation.
.IP 26
Read error. Various reading problems.
.IP 27
Out of memory. A memory allocation request failed.
.IP 28
Operation timeout. The specified time-out period was reached according to the
conditions.
.IP 29
FTP couldn't set ASCII. The server returned an unknown reply.
.IP 30
FTP PORT failed. The PORT command failed.
.IP 31
FTP couldn't use REST. The REST command failed.
.IP 32
FTP couldn't use SIZE. The SIZE command failed. The command is an extension
to the original FTP spec RFC 959.
.IP 33
HTTP range error. The range "command" didn't work.
.IP 34
HTTP post error. Internal post-request generation error.
.IP 35
SSL connect error. The SSL handshaking failed.
.IP 36
FTP bad download resume. Couldn't continue an earlier aborted download.
.IP 37
FILE couldn't read file. Failed to open the file. Permissions?
.IP 38
LDAP cannot bind. LDAP bind operation failed.
.IP 39
LDAP search failed.
.IP 40
Library not found. The LDAP library was not found.
.IP 41
Function not found. A required LDAP function was not found.
.IP XX
There will appear more error codes here in future releases. The existing ones
are meant to never change.
.SH BUGS
If you do find any (or have other suggestions), mail Daniel Stenberg
<Daniel.Stenberg@haxx.se>.
.SH AUTHORS / CONTRIBUTORS
 - Daniel Stenberg <Daniel.Stenberg@haxx.se>
 - 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@haxx.se>
 - Troy Engel <tengel@sonic.net>
 - Ryan Nelson <ryan@inch.com>
 - Björn Stenberg <Bjorn.Stenberg@haxx.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@computer.org>
 - Matthew Clarke <clamat@van.maves.ca>
 - Linus Nielsen <Linus.Nielsen@haxx.se>
 - Felix von Leitner <felix@convergence.de>
 - Dan Zitter <dzitter@zitter.net>
 - Jongki Suwandi <Jongki.Suwandi@eng.sun.com>
 - Chris Maltby <chris@aurema.com>
 - Ron Zapp <rzapper@yahoo.com>
 - Paul Marquis <pmarquis@iname.com>
 - Ellis Pritchard <ellis@citria.com>
 - Damien Adant <dams@usa.net>
 - Chris <cbayliss@csc.come>
 - Marco G. Salvagno <mgs@whiz.cjb.net>
 - Paul Marquis <pmarquis@iname.com>
 - David LeBlanc <dleblanc@qnx.com>
 - Rich Gray at Plus Technologies
 - Luong Dinh Dung <u8luong@lhsystems.hu>
 - Torsten Foertsch <torsten.foertsch@gmx.net>
 - Kristian Köhntopp <kris@koehntopp.de>
 - Fred Noz <FNoz@siac.com>
 - Caolan McNamara <caolan@csn.ul.ie>

.SH WWW
http://curl.haxx.se
.SH FTP
ftp://ftp.sunet.se/pub/www/utilities/curl/
.SH "SEE ALSO"
.BR ftp (1),
.BR wget (1),
.BR snarf (1)