curl_easy_setopt.3

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user.
.TP
.B CURLOPT_USERPWD
Pass a char * as parameter, which should be [user name]:[password] to use for
the connection. If both the colon and password is left out, you will be
prompted for it while using a colon with no password will make libcurl use an
empty password. \fICURLOPT_PASSWDFUNCTION\fP can be used to set your own
prompt function.

When using HTTP and CURLOPT_FOLLOWLOCATION, libcurl might perform several
requests to possibly different hosts. libcurl will only send this user and
password information to hosts using the initial host name (unless
CURLOPT_UNRESTRICTED_AUTH is set), so if libcurl follows locations to other
hosts it will not send the user and password to those. This is enforced to
prevent accidental information leakage.
.TP
.B CURLOPT_PROXYUSERPWD
Pass a char * as parameter, which should be [user name]:[password] to use for
the connection to the HTTP proxy. If the password is left out, you will be
prompted for it. \fICURLOPT_PASSWDFUNCTION\fP can be used to set your own
prompt function.
.TP
.B CURLOPT_HTTPAUTH
Pass a long as parameter, which is set to a bitmask, to tell libcurl what
authentication method(s) you want it to use. The available bits are listed
below. If more than one bit is set, libcurl will first query the site to see
what authentication methods it supports and then pick the best one you allow
it to use. Note that for some methods, this will induce an extra network
round-trip. Set the actual name and password with the \fICURLOPT_USERPWD\fP
option. (Added in 7.10.6)
.RS
.TP 5
.B CURLAUTH_BASIC
HTTP Basic authentication. This is the default choice, and the only method
that is in wide-spread use and supported virtually everywhere. This is sending
the user name and password over the network in plain text, easily captured by
others.
.TP
.B CURLAUTH_DIGEST
HTTP Digest authentication.  Digest authentication is defined in RFC2617 and
is a more secure way to do authentication over public networks than the
regular old-fashioned Basic method.
.TP
.B CURLAUTH_GSSNEGOTIATE
HTTP GSS-Negotiate authentication. The GSS-Negotiate method was designed by
Microsoft and is used in their web aplications. 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.
.TP
.B CURLAUTH_NTLM
HTTP NTLM authentication. A proprietary protocol invented and used by
Microsoft. It uses a challenge-response and hash concept similar to Digest to
prevent the password from being evesdropped.
.TP
.B CURLAUTH_ANY
This is a convenience macro that sets all bits and thus makes libcurl pick any
it finds suitable. libcurl will automaticly select the one it finds most
secure.
.TP
.B CURLAUTH_ANYSAFE
This is a convenience macro that sets all bits except Basic and thus makes
libcurl pick any it finds suitable. libcurl will automaticly select the one it
finds most secure.
.RE
.TP
.B CURLOPT_PROXYAUTH
Pass a long as parameter, which is set to a bitmask, to tell libcurl what
authentication method(s) you want it to use for your proxy authentication.  If
more than one bit is set, libcurl will first query the site to see what
authentication methods it supports and then pick the best one you allow it to
use. Note that for some methods, this will induce an extra network
round-trip. Set the actual name and password with the
\fICURLOPT_PROXYUSERPWD\fP option. The bitmask can be constructed by or'ing
together the bits listed above for the \fICURLOPT_HTTPAUTH\fP option. As of
this writing, only Basic and NTLM work. (Added in 7.10.7)
.PP
.SH HTTP OPTIONS
.TP 0.4i
.B CURLOPT_ENCODING
Sets the contents of the Accept-Encoding: header sent in an HTTP
request, and enables decoding of a response when a Content-Encoding:
header is received.  Three encodings are supported: \fIidentity\fP,
which does nothing, \fIdeflate\fP which requests the server to
compress its response using the zlib algorithm, and \fIgzip\fP which
requests the gzip algorithm.  If a zero-length string is set, then an
Accept-Encoding: header containing all supported encodings is sent.

This is a request, not an order; the server may or may not do it.  This
option must be set (to any non-NULL value) or else any unsolicited
encoding done by the server is ignored. See the special file
lib/README.encoding for details.
.TP
.B CURLOPT_FOLLOWLOCATION
A non-zero parameter tells the library to follow any Location: header that the
server sends as part of a HTTP header.

\fBNOTE:\fP this means that the library will re-send the same request on the
new location and follow new Location: headers all the way until no more such
headers are returned. \fICURLOPT_MAXREDIRS\fP can be used to limit the number
of redirects libcurl will follow.
.TP
.B CURLOPT_UNRESTRICTED_AUTH
A non-zero parameter tells the library it can continue to send authentication
(user+password) when following locations, even when hostname changed. Note
that this is meaningful only when setting \fICURLOPT_FOLLOWLOCATION\fP.
.TP
.B CURLOPT_MAXREDIRS
Pass a long. The set number will be the redirection limit. If that many
redirections have been followed, the next redirect will cause an error
(\fICURLE_TOO_MANY_REDIRECTS\fP). This option only makes sense if the
\fICURLOPT_FOLLOWLOCATION\fP is used at the same time.
.TP
.B CURLOPT_PUT
A non-zero parameter tells the library to use HTTP PUT to transfer data. The
data should be set with CURLOPT_READDATA and CURLOPT_INFILESIZE.
.TP
.B CURLOPT_POST
A non-zero parameter tells the library to do a regular HTTP post. This is a
normal application/x-www-form-urlencoded kind, which is the most commonly used
one by HTML forms. See the CURLOPT_POSTFIELDS option for how to specify the
data to post and CURLOPT_POSTFIELDSIZE in how to set the data size. Starting
with libcurl 7.8, this option is obsolete. Using the CURLOPT_POSTFIELDS option
will imply this option.
.TP
.B CURLOPT_POSTFIELDS
Pass a char * as parameter, which should be the full data to post in a HTTP
post operation. You need to make sure that the data is formatted the way you
want the server to receive it. libcurl will not convert or encode it for
you. Most web servers will assume this data to be url-encoded. Take note.

This POST is a normal application/x-www-form-urlencoded kind (and libcurl will
set that Content-Type by default when this option is used), which is the most
commonly used one by HTML forms. See also the CURLOPT_POST. Using
CURLOPT_POSTFIELDS implies CURLOPT_POST.

\fBNote:\fP to make multipart/formdata posts (aka rfc1867-posts), check out
the \fICURLOPT_HTTPPOST\fP option.
.TP
.B CURLOPT_POSTFIELDSIZE
If you want to post data to the server without letting libcurl do a strlen()
to measure the data size, this option must be used. When this option is used
you can post fully binary data, which otherwise is likely to fail. If this
size is set to zero, the library will use strlen() to get the size.
.TP
.B CURLOPT_HTTPPOST
Tells libcurl you want a multipart/formdata HTTP POST to be made and you
instruct what data to pass on to the server.  Pass a pointer to a linked list
of HTTP post structs as parameter.  The linked list should be a fully valid
list of 'struct HttpPost' structs properly filled in. The best and most
elegant way to do this, is to use \fIcurl_formadd(3)\fP as documented. The
data in this list must remain intact until you close this curl handle again
with \fIcurl_easy_cleanup(3)\fP.
.TP
.B CURLOPT_REFERER
Pass a pointer to a zero terminated string as parameter. It will be used to
set the Referer: header in the http request sent to the remote server. This
can be used to fool servers or scripts. You can also set any custom header
with \fICURLOPT_HTTPHEADER\fP.
.TP
.B CURLOPT_USERAGENT
Pass a pointer to a zero terminated string as parameter. It will be used to
set the User-Agent: header in the http request sent to the remote server. This
can be used to fool servers or scripts. You can also set any custom header
with \fICURLOPT_HTTPHEADER\fP.
.TP
.B CURLOPT_HTTPHEADER
Pass a pointer to a linked list of HTTP headers to pass to the server in your
HTTP request. The linked list should be a fully valid list of \fBstruct
curl_slist\fP structs properly filled in. Use \fIcurl_slist_append(3)\fP to
create the list and \fIcurl_slist_free_all(3)\fP to clean up an entire
list. If you add a header that is otherwise generated and used by libcurl
internally, your added one will be used instead. If you add a header with no
contents as in 'Accept:' (no data on the right side of the colon), the
internally used header will get disabled. Thus, using this option you can add
new headers, replace internal headers and remove internal headers. The
headers included in the linked list must not be CRLF-terminated, because
curl adds CRLF after each header item. Failure to comply with this will
result in strange bugs because the server will most likely ignore part
of the headers you specified.

The first line in a request (usually containing a GET or POST) is not a header
and cannot be replaced using this option. Only the lines following the
request-line are headers.

\fBNOTE:\fPThe most commonly replaced headers have "shortcuts" in the options
CURLOPT_COOKIE, CURLOPT_USERAGENT and CURLOPT_REFERER.
.TP
.B CURLOPT_HTTP200ALIASES
Pass a pointer to a linked list of aliases to be treated as valid HTTP 200
responses.  Some servers respond with a custom header response line.  For
example, IceCast servers respond with "ICY 200 OK".  By including this string
in your list of aliases, the response will be treated as a valid HTTP header
line such as "HTTP/1.0 200 OK". (Added in 7.10.3)

The linked list should be a fully valid list of struct curl_slist structs, and
be properly filled in.  Use \fIcurl_slist_append(3)\fP to create the list and
\fIcurl_slist_free_all(3)\fP to clean up an entire list.

\fBNOTE:\fPThe alias itself is not parsed for any version strings.  So if your
alias is "MYHTTP/9.9", Libcurl will not treat the server as responding with
HTTP version 9.9.  Instead Libcurl will use the value set by option
\fICURLOPT_HTTP_VERSION\fP.
.TP
.B CURLOPT_COOKIE
Pass a pointer to a zero terminated string as parameter. It will be used to
set a cookie in the http request. The format of the string should be
NAME=CONTENTS, where NAME is the cookie name and CONTENTS is what the cookie
should contain.

If you need to set mulitple cookies, you need to set them all using a single
option and thus you need to concat them all in one single string. Set multiple
cookies in one string like this: "name1=content1; name2=content2;" etc.

Using this option multiple times will only make the latest string override the
previously ones.
.TP
.B CURLOPT_COOKIEFILE
Pass a pointer to a zero terminated string as parameter. It should contain the
name of your file holding cookie data to read. The cookie data may be in
Netscape / Mozilla cookie data format or just regular HTTP-style headers
dumped to a file.

Given an empty or non-existing file, this option will enable cookies for this
curl handle, making it understand and parse received cookies and then use
matching cookies in future request.
.TP
.B CURLOPT_COOKIEJAR
Pass a file name as char *, zero terminated. This will make libcurl write all
internally known cookies to the specified file when \fIcurl_easy_cleanup(3)\fP
is called. If no cookies are known, no file will be created. Specify "-" to
instead have the cookies written to stdout. Using this option also enables
cookies for this session, so if you for example follow a location it will make
matching cookies get sent accordingly.

.B NOTE
If the cookie jar file can't be created or written to (when the
curl_easy_cleanup() is called), libcurl will not and cannot report an error
for this. Using CURLOPT_VERBOSE or CURLOPT_DEBUGFUNCTION will get a warning to
display, but that is the only visible feedback you get about this possibly
lethal situation.
.TP
.B CURLOPT_TIMECONDITION
Pass a long as parameter. This defines how the CURLOPT_TIMEVALUE time value is
treated. You can set this parameter to TIMECOND_IFMODSINCE or
TIMECOND_IFUNMODSINCE. This is a HTTP-only feature. (TBD)
.TP
.B CURLOPT_TIMEVALUE
Pass a long as parameter. This should be the time in seconds since 1 jan 1970,
and the time will be used in a condition as specified with
CURLOPT_TIMECONDITION.
.TP
.B CURLOPT_HTTPGET
Pass a long. If the long is non-zero, this forces the HTTP request to get back
to GET. Only really usable if POST, PUT or a custom request have been used
previously using the same curl handle.
.TP
.B CURLOPT_HTTP_VERSION
Pass a long, set to one of the values described below. They force libcurl to
use the specific HTTP versions. This is not sensible to do unless you have a
good reason.
.RS
.TP 5
.B CURL_HTTP_VERSION_NONE
We don't care about what version the library uses. libcurl will use whatever
it thinks fit.
.TP
.B CURL_HTTP_VERSION_1_0
Enforce HTTP 1.0 requests.
.TP
.B CURL_HTTP_VERSION_1_1
Enforce HTTP 1.1 requests.
.RE
.PP
.SH FTP OPTIONS
.TP 0.4i
.B CURLOPT_FTPPORT
Pass a pointer to a zero terminated string as parameter. It will be used to
get the IP address to use for the ftp PORT instruction. The PORT instruction
tells the remote server to connect to our specified IP address. The string may
be a plain IP address, a host name, an network interface name (under Unix) or
just a '-' letter to let the library use your systems default IP
address. Default FTP operations are passive, and thus won't use PORT.

You disable PORT again and go back to using the passive version by setting
this option to NULL.
.TP
.B CURLOPT_QUOTE
Pass a pointer to a linked list of FTP commands to pass to the server prior to
your ftp request. This will be done before any other FTP commands are issued
(even before the CWD command). The linked list should be a fully valid list of
'struct curl_slist' structs properly filled in. Use \fIcurl_slist_append(3)\fP
to append strings (commands) to the list, and clear the entire list afterwards
with \fIcurl_slist_free_all(3)\fP. Disable this operation again by setting a
NULL to this option.
.TP
.B CURLOPT_POSTQUOTE
Pass a pointer to a linked list of FTP commands to pass to the server after
your ftp transfer request. The linked list should be a fully valid list of
struct curl_slist structs properly filled in as described for
\fICURLOPT_QUOTE\fP. Disable this operation again by setting a NULL to this
option.
.TP
.B CURLOPT_PREQUOTE
Pass a pointer to a linked list of FTP commands to pass to the server after
the transfer type is set. The linked list should be a fully valid list of
struct curl_slist structs properly filled in as described for
\fICURLOPT_QUOTE\fP. Disable this operation again by setting a NULL to this
option.
.TP
.B CURLOPT_FTPLISTONLY
A non-zero parameter tells the library to just list the names of an ftp