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curl
!!!curl
NAME
SYNOPSIS
DESCRIPTION
URL
OPTIONS
FILES
ENVIRONMENT
EXIT CODES
BUGS
AUTHORS / CONTRIBUTORS
WWW
FTP
SEE ALSO
----
!!NAME


curl - transfer a URL
!!SYNOPSIS


__curl [[options]__ ''[[URL...]''
!!DESCRIPTION


__curl__ is a client to get documents/files from or send
documents to a server, using any of the supported protocols
(HTTP, HTTPS, FTP, GOPHER, DICT, TELNET, LDAP or FILE). 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 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


You can specify any amount of URLs on the command line. They
will be fetched in a sequential manner in the specified
order.


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.
!!OPTIONS


-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.


If this option is used twice, the second one will disable
append mode again.


-A/--user-agent


(HTTP) Specify the User-Agent string to send to the HTTP
server. Some badly done CGIs fail if its not set to


If this option is set more than once, the last one will be
the one that's used.


-b/--cookie


(HTTP) Pass the data to the HTTP server as a cookie. It is
supposedly the data previously received from the server in a


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


__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!


If this option is set more than once, the last one will be
the one that's used.


-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


If this option is used twice, the second one will disable
ASCII usage.


--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 (Option
added in curl 7.9)''


If this option is used severl times, the last one will
override the others.


--connect-timeout


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. This
option didn't work in win32 systems until 7.7.2. See also
the ''--max-time'' option.


If this option is used several times, the last one will be
used.


-c/--cookie-jar


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,


If this option is used several times, the last specfied file
name will be used.


-C/--continue-at


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.


Use


If this option is used several times, the last one will be
used.


-d/--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


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


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


(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


(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.


--disable-epsv


(FTP) Tell curl to disable the use of the EPSV command when
doing passive FTP downloads. 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


(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!


If this option is used several times, the last one will be
used.


-e/--referer


(HTTP) Sends the
-L/--location'' you can
append
''


If this option is used several times, the last one will be
used.


--egd-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


(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.


--cacert


(HTTPS) Tells curl to use the specified certificate file to
verify the peer. The certificate must be in PEM
format.


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 a HTML
document stating so (which often also describes why and
more). This flag will prevent curl from outputting that and
fail silently instead.


If this option is used twice, the second will again disable
silent failure.


-F/--form


(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


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. This goes for both @
and


This option can be used multiple times.


-g/--globoff


This option switches off the


-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.
(Option added in curl 7.9)


-h/--help


Usage help.


-H/--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.


This option can be used multiple times.


-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


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) 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.


If this option is used twice, the second will again disable
header only.


--krb4


(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.


If this option is used several times, the last one will be
used.


-K/--config


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 inclosed 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.


This option can be used multiple times.


-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.


If this option is used twice, the second will again disable
list only.


-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.


If this option is used twice, the second will again disable
location following.


-m/--max-time


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. 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
__


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.


-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.


-o/--output


Write output to


curl http://{one,two}.site.com -o


or use several variables like:


curl http://{site,host}.host[[1-5].com -o


You may use this option as many times as you have number of
URLs.


-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.)


You may use this option as many times as you have number of
URLs.


-p/--proxytunnel


When an HTTP proxy is used, 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/--ftpport


(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.


__interface__


i.e


__IP address__


i.e


__host name__


i.e


__-__


(any single-letter string) to make it pick the machine's
default


If this option is used several times, the last one will be
used.


-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


(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.


This option can be used multiple times.


--random-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
''--edg-file'' option.


-r/--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.


-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
mute.


-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.


-t/--telnet-option


Pass options to the telnet protocol. Supported options
are:


TTYPE=


XDISPLOC=


NEW_ENV=


-T/--upload-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


If this option is used several times, the last one will be
used.


-u/--user


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.


If this option is used several times, the last one will be
used.


-U/--proxy-user


Specify user and password to use for Proxy authentication.
If no password is specified, curl will ask for it
interactively.


If this option is used several times, the last one will be
used.


--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'' or the
''-O'' options.


-v/--verbose


Makes the fetching more verbose/talkative. Mostly usable for
debugging. Lines starting with '


If this option is used twice, the second will again disable
verbose.


-V/--version


Displays the full version of curl, libcurl and other 3rd
party libraries linked with the executable.


-w/--write-out


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


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.


__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_starttransfer__


The time, in seconds, it took from the start until the first
byte is just about to be transfered. 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. (Added in 7.9.5)


If this option is used several times, the last one will be
used.


-x/--proxy


Use specified HTTP proxy. If the port number is not
specified, it is assumed at port 1080.


__Note__ that all operations that are performed over a
HTTP proxy will transparantly 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.


If this option is used several times, the last one will be
used.


-X/--request


(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.


If this option is used several times, the last one will be
used.


-y/--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.


If this option is used several times, the last one will be
used.


-Y/--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.


If this option is used several times, the last one will be
used.


-z/--time-cond


(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)__ or __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.


-3/--sslv3


(HTTPS) Forces curl to use SSL version 3 when negotiating
with a remote SSL server.


-2/--sslv2


(HTTPS) Forces curl to use SSL version 2 when negotiating
with a remote SSL server.


-0/--http1.0


(HTTP) Forces curl to issue its requests using HTTP 1.0
instead of using its internally preferred: HTTP
1.1.


-#/--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.


--crlf


(FTP) Convert LF to CRLF in upload. Useful for MVS
(OS/390).


If this option is used twice, the second will again disable
crlf converting.


--stderr


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.
!!FILES


''~/.curlrc''


Default config file.
!!ENVIRONMENT


http_proxy [[protocol://]


Sets proxy server to use for HTTP.


HTTPS_PROXY [[protocol://]


Sets proxy server to use for HTTPS.


FTP_PROXY [[protocol://]


Sets proxy server to use for FTP.


GOPHER_PROXY [[protocol://]


Sets proxy server to use for GOPHER.


ALL_PROXY [[protocol://]


Sets proxy server to use if no protocol-specific proxy is
set.


NO_PROXY


list of host names that shouldn't go through any proxy. If
set to a asterisk
!!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:


1


Unsupported protocol. This build of curl has no support for
this protocol.


2


Failed to initialize.


3


URL malformat. The syntax was not correct.


4


URL user malformatted. The user-part of the URL syntax was
not correct.


5


Couldn't resolve proxy. The given proxy host could not be
resolved.


6


Couldn't resolve host. The given remote host was not
resolved.


7


Failed to connect to host.


8


FTP weird server reply. The server sent data curl couldn't
parse.


9


FTP access denied. The server denied login.


10


FTP user/password incorrect. Either one or both were not
accepted by the server.


11


FTP weird PASS reply. Curl couldn't parse the reply sent to
the PASS request.


12


FTP weird USER reply. Curl couldn't parse the reply sent to
the USER request.


13


FTP weird PASV reply, Curl couldn't parse the reply sent to
the PASV request.


14


FTP weird 227 format. Curl couldn't parse the 227-line the
server sent.


15


FTP can't get host. Couldn't resolve the host IP we got in
the 227-line.


16


FTP can't reconnect. Couldn't connect to the host we got in
the 227-line.


17


FTP couldn't set binary. Couldn't change transfer method to
binary.


18


Partial file. Only a part of the file was
transfered.


19


FTP couldn't RETR file. The RETR command
failed.


20


FTP write error. The transfer was reported bad by the
server.


21


FTP quote error. A quote command returned error from the
server.


22


HTTP not found. The requested page was not found. This
return code only appears if --fail is used.


23


Write error. Curl couldn't write data to a local filesystem
or similar.


24


Malformat user. User name badly specified.


25


FTP couldn't STOR file. The server denied the STOR
operation.


26


Read error. Various reading problems.


27


Out of memory. A memory allocation request
failed.


28


Operation timeout. The specified time-out period was reached
according to the conditions.


29


FTP couldn't set ASCII. The server returned an unknown
reply.


30


FTP PORT failed. The PORT command failed.


31


FTP couldn't use REST. The REST command failed.


32


FTP couldn't use SIZE. The SIZE command failed. The command
is an extension to the original FTP spec RFC
959.


33


HTTP range error. The range


34


HTTP post error. Internal post-request generation
error.


35


SSL connect error. The SSL handshaking failed.


36


FTP bad download resume. Couldn't continue an earlier
aborted download.


37


FILE couldn't read file. Failed to open the file.
Permissions?


38


LDAP cannot bind. LDAP bind operation failed.


39


LDAP search failed.


40


Library not found. The LDAP library was not
found.


41


Function not found. A required LDAP function was not
found.


42


Aborted by callback. An application told curl to abort the
operation.


43


Internal error. A function was called with a bad
parameter.


44


Internal error. A function was called in a bad
order.


45


Interface error. A specified outgoing interface could not be
used.


46


Bad password entered. An error was signaled when the
password was entered.


47


Too many redirects. When following redirects, curl hit the
maximum amount.


48


Unknown TELNET option specified.


49


Malformed telnet option.


51


The remote peer's SSL certificate wasn't ok


52


The server didn't reply anything, which here is considered
an error.


XX


There will appear more error codes here in future releases.
The existing ones are meant to never change.
!!BUGS


If you do find bugs, mail them to
curl-bug@haxx.se.
!!AUTHORS / CONTRIBUTORS


Daniel Stenberg is the main author, but the whole list of
contributors is found in the separate THANKS
file.
!!WWW


http://curl.haxx.se
!!FTP


ftp://ftp.sunet.se/pub/www/utilities/curl/
!!SEE ALSO


ftp(1), wget(1), snarf(1)
----
2 pages link to curl(1):
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Last edited on Tuesday, June 4, 2002 12:21:52 am by "perry"
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