Computer Science
curl(1) Curl Manual curl(1)
NAME
curl - get a URL with FTP, TELNET, LDAP, GOPHER, DICT,
FILE, HTTP or HTTPS syntax.
SYNOPSIS
curl [options] url
DESCRIPTION
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.
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 lead-
ing 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]/vol-
ume[1-4]part{a,b,c,index}.html
OPTIONS
-a/--append
(FTP) When used in a ftp upload, this will tell
curl to append to the target file instead of over-
writing it. If the file doesn't exist, it will be
created.
-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.
-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 acti-
vates the "cookie awareness" 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/--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".
-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.
-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 trans-
fered 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.
-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.
-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.
-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.
-E/--cert <certificate[:password]>
(HTTPS) Tells curl to use the specified certificate
file when getting a file with HTTPS. The certifi-
cate must be in PEM format. If the optional pass-
word isn't specified, it will be queried for on the
terminal. Note that this certificate is the private
key and the private certificate concatenated!
-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.
-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:
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.
-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.
-i/--include
(HTTP) Include the HTTP-header in the output. The
HTTP-header includes things like server-name, date
of the document, HTTP-version and more...
-I/--head
(HTTP/FTP) 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.
-K/--config <config file>
Specify which config file to read curl arguments
from. The config file is a text file in which com-
mand line arguments can be written which then will
be used as if they were written on the actual com-
mand 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.
-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 direc-
tory since the normal directory view doesn't use a
standard look or format.
-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.
-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.
-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 typ-
ically used for ftp on unix. If used with http,
curl will enable user authentication. See netrc(4)
for details on the file format. Curl will not com-
plain if that file hasn't the right permissions (it
should not be world nor group readable). The envi-
ronment 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
machine host.domain.com user myself password secret
-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 vari-
able 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"
-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.)
-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 speci-
fied 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 inter-
face'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
-q If used as the first parameter on the command line,
the $HOME/.curlrc file will not be read and used as
a config file.
-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!
-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.
-s/--silent
Silent mode. Don't show progress meter or error
messages. Makes Curl mute.
-S/--show-error
When used with -s it makes curl show error message
if it fails.
-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.
-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 direc-
tory 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.
-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.
-U/--proxy-user <user:password>
Specify user and password to use for Proxy authen-
tication. If no password is specified, curl will
ask for it interactively.
-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.
-V/--version
Displays the full version of curl, libcurl and
other 3rd party libraries linked with the exe-
cutable.
-x/--proxy <proxyhost[:port]>
Use specified proxy. If the port number is not
specified, it is assumed at port 1080.
-X/--http-request <request>
(HTTP) Specifies a custom request to use when com-
municating 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.
-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.
-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.
-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 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.
-3/--sslv3
(HTTPS) Forces curl to use SSL version 3 when nego-
tiating with a remote SSL server.
-2/--sslv2
(HTTPS) Forces curl to use SSL version 2 when nego-
tiating with a remote SSL server.
-#/--progress-bar
Make curl display progress information as a
progress bar instead of the default statistics.
--crlf (FTP) Convert LF to CRLF in upload. Useful for MVS
(OS/390).
--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.
FILES
~/.curlrc
Default config file.
ENVIRONMENT
HTTP_PROXY [protocol://]<host>[:port]
Sets proxy server to use for HTTP.
HTTPS_PROXY [protocol://]<host>[:port]
Sets proxy server to use for HTTPS.
FTP_PROXY [protocol://]<host>[:port]
Sets proxy server to use for FTP.
GOPHER_PROXY [protocol://]<host>[:port]
Sets proxy server to use for GOPHER.
ALL_PROXY [protocol://]<host>[:port]
Sets proxy server to use if no protocol-specific
proxy is set.
NO_PROXY <comma-separated list of hosts>
list of host names that shouldn't go through any
proxy. If set to a asterisk '*' only, it matches
all hosts.
COLUMNS <integer>
The width of the terminal. This variable only
affects curl when the --progress-bar option is
used.
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.
BUGS
If you do find any (or have other suggestions), mail
Daniel Stenberg <Daniel.Stenberg@haxx.nu>.
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>
- Andrs Garca <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>
- Jrn 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>
WWW
http://curl.haxx.nu
FTP
ftp://ftp.sunet.se/pub/www/utilities/curl/
SEE ALSO
ftp(1), wget(1), snarf(1)
Curl 6.3 8 November 1999 1
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