curl.1

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When curl is invoked, it always (unless \fI-q\fP 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.
.IP "--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 \fI-Y/--speed-limit\fP 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.
.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.

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.
.IP "--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)
.IP "-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 \fI-i/--include\fP or \fI-I/--head\fP, 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 \fI--location-trusted\fP on how
to change this. You can limit the amount of redirects to follow by using the
\fI--max-redirs\fP option.

If this option is used twice, the second will again disable location following.
.IP "--location-trusted"
(HTTP/HTTPS) Like \fI-L/--location\fP, 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.
.IP "--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.
.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.  See also the \fI--connect-timeout\fP option.

If this option is used several times, the last one will be used.
.IP "-M/--manual"
Manual. Display the huge help text.
.IP "-n/--netrc"
Makes curl scan the \fI.netrc\fP 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)
or
.BR 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 \fI.netrc\fP 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"

If this option is used twice, the second will again disable netrc usage.
.IP "--netrc-optional"
Very similar to \fI--netrc\fP, but this option makes the .netrc usage
\fBoptional\fP and not mandatory as the \fI--netrc\fP does.
.IP "--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 \fI-V/--version\fP 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.
.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.

If this option is used twice, the second will again switch on buffering.
.IP "--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
\fI--proxy-ntlm\fP.

This option requires that the library was built with SSL support. Use
\fI-V/--version\fP to see if your curl supports NTLM.

If this option is used several times, the following occurrences make no
difference.
.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"

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

See also the \fI--create-dirs\fP option to create the local directories
dynamically.
.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.)

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.
.IP "--pass <phrase>"
(SSL) Pass phrase for the private key

If this option is used several times, the last one will be used.
.IP "--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.
.IP "--proxy-basic"
Tells curl to use HTTP Basic authentication when communicating with the given
proxy. Use \fI--basic\fP 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.
.IP "--proxy-digest"
Tells curl to use HTTP Digest authentication when communicating with the given
proxy. Use \fI--digest\fP for enabling HTTP Digest with a remote host.

If this option is used twice, the second will again disable proxy HTTP Digest.
.IP "--proxy-ntlm"
Tells curl to use HTTP NTLM authentication when communicating with the given
proxy. Use \fI--ntlm\fP for enabling NTLM with a remote host.

If this option is used twice, the second will again disable proxy HTTP NTLM.
.IP "-p/--proxytunnel"
When an HTTP proxy is used (\fI-x/--proxy\fP), 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.
.IP "-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:
.RS
.IP interface
i.e "eth0" to specify which interface's IP address you want to use  (Unix only)
.IP "IP address"
i.e "192.168.10.1" to specify exact IP number
.IP "host name"
i.e "my.host.domain" to specify machine
.IP "-"
make curl pick the same IP address that is already used for the control
connection
.RE

If this option is used several times, the last one will be used. Disable the
use of PORT with \fI--ftp-pasv\fP. Disable the attempt to use the EPRT command
instead of PORT by using \fI--disable-eprt\fP. EPRT is really PORT++.
.IP "-q"
If used as the first parameter on the command line, the \fIcurlrc\fP config
file will not be read and used. See the \fI-K/--config\fP for details on the
default config file search path.
.IP "-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.
.IP "--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 \fI--egd-file\fP option.
.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.

If this option is used several times, the last one will be used.
.IP "-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.
.IP "--retry <num>"
If a transient error is returned when curl tries to perform a transfer, it