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libcurl Manual curl_easy_setopt(3)

NAME

curl_easy_setopt - set options for a curl easy handle

SYNOPSIS

#include

CURLcode curl_easy_setopt(CURL *handle, CURLoption option,

parameter);

DESCRIPTION

curl_easy_setopt() is used to tell libcurl how to behave. By

using the appropriate options to curl_easy_setopt, you can

change libcurl's behavior. All options are set with the option followed by a parameter. That parameter can be a

long, a function pointer, an object pointer or a curl_off_t,

depending on what the specific option expects. Read this manual carefully as bad input values may cause libcurl to behave badly! You can only set one option in each function

call. A typical application uses many curl_easy_setopt()

calls in the setup phase.

Options set with this function call are valid for all forth-

coming transfers performed using this handle. The options are not in any way reset between transfers, so if you want subsequent transfers with different options, you must change them between the transfers. You can optionally reset all

options back to internal default with curl_easy_reset(3).

Strings passed to libcurl as 'char *' arguments, are copied by the library; thus the string storage associated to the

pointer argument may be overwritten after curl_easy_setopt()

returns. Exceptions to this rule are described in the option details below. Before version 7.17.0, strings were not copied. Instead the user was forced keep them available until libcurl no longer needed them.

The handle is the return code from a curl_easy_init(3) or

curl_easy_duphandle(3) call.

BEHAVIOR OPTIONS

CURLOPT_VERBOSE

Set the parameter to 1 to get the library to display a lot of verbose information about its operations. Very

useful for libcurl and/or protocol debugging and under-

standing. The verbose information will be sent to

stderr, or the stream set with CURLOPT_STDERR.

You hardly ever want this set in production use, you will almost always want this when you debug/report problems. Another neat option for debugging is the libcurl 7.20.0 Last change: 1 Jan 2010 1

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CURLOPT_DEBUGFUNCTION.

CURLOPT_HEADER

A parameter set to 1 tells the library to include the header in the body output. This is only relevant for protocols that actually have headers preceding the data (like HTTP).

CURLOPT_NOPROGRESS

A parameter set to 1 tells the library to shut off the

built-in progress meter completely.

Future versions of libcurl are likely to not have any

built-in progress meter at all.

CURLOPT_NOSIGNAL

Pass a long. If it is 1, libcurl will not use any func-

tions that install signal handlers or any functions that cause signals to be sent to the process. This

option is mainly here to allow multi-threaded unix

applications to still set/use all timeout options etc, without risking getting signals. (Added in 7.10) If this option is set and libcurl has been built with the standard name resolver, timeouts will not occur while the name resolve takes place. Consider building

libcurl with c-ares support to enable asynchronous DNS

lookups, which enables nice timeouts for name resolves without signals.

CURLOPT_WILDCARDMATCH

Set this option to 1 if you want to transfer multiple files according to a file name pattern. The pattern can

be specified as part of the CURLOPT_URL option, using

an fnmatch-like pattern (Shell Pattern Matching) in the

last part of URL (file name). By default, libcurl uses its internal wildcard matching

implementation. You can provide your own matching func-

tion by the CURLOPT_FNMATCH_FUNCTION option.

This feature is only supported by the FTP download for now. A brief introduction of its syntax follows:

* - ASTERISK

ftp://example.com/some/path/*.txt (for all txt's from the root directory)

? - QUESTION MARK

Question mark matches any (exactly one) character. libcurl 7.20.0 Last change: 1 Jan 2010 2

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ftp://example.com/some/path/photo?.jpeg

[ - BRACKET EXPRESSION

The left bracket opens a bracket expression. The question mark and asterisk have no special meaning in a bracket expression. Each bracket expression ends by the right bracket and matches exactly one character. Some examples follow:

[a-zA-Z0-9] or [f-gF-G] - character interval

[abc] - character enumeration

[^abc] or [!abc] - negation

[[:name:]] class expression. Supported classes are alnum,lower, space, alpha, digit, print, upper, blank, graph, xdigit.

[][-!^] - special case - matches only '-', ']',

'[', '!' or '^'. These characters have no special purpose.

[\[\]\\] - escape syntax. Matches '[', ']' or '\'.

Using the rules above, a file name pattern can be constructed:

ftp://example.com/some/path/[a-z[:upper:]\\].jpeg

(This was added in 7.21.0) CALLBACK OPTIONS

CURLOPT_WRITEFUNCTION

Function pointer that should match the following proto-

type: size_t function( void *ptr, size_t size, size_t

nmemb, void *userdata); This function gets called by libcurl as soon as there is data received that needs to be saved. The size of the data pointed to by ptr is

size multiplied with nmemb, it will not be zero ter-

minated. Return the number of bytes actually taken care of. If that amount differs from the amount passed to your function, it'll signal an error to the library. This will abort the transfer and return

CURLE_WRITE_ERROR.

From 7.18.0, the function can return

CURL_WRITEFUNC_PAUSE which then will cause writing to

this connection to become paused. See

curl_easy_pause(3) for further details.

This function may be called with zero bytes data if the libcurl 7.20.0 Last change: 1 Jan 2010 3

libcurl Manual curl_easy_setopt(3)

transferred file is empty. Set this option to NULL to get the internal default function. The internal default function will write the

data to the FILE * given with CURLOPT_WRITEDATA.

Set the userdata argument with the CURLOPT_WRITEDATA

option. The callback function will be passed as much data as possible in all invokes, but you cannot possibly make any assumptions. It may be one byte, it may be thousands. The maximum amount of data that can be passed to the write callback is defined in the curl.h

header file: CURL_MAX_WRITE_SIZE.

CURLOPT_WRITEDATA

Data pointer to pass to the file write function. If you

use the CURLOPT_WRITEFUNCTION option, this is the

pointer you'll get as input. If you don't use a call-

back, you must pass a 'FILE *' as libcurl will pass this to fwrite() when writing data.

The internal CURLOPT_WRITEFUNCTION will write the data

to the FILE * given with this option, or to stdout if this option hasn't been set. If you're using libcurl as a win32 DLL, you MUST use

the CURLOPT_WRITEFUNCTION if you set this option or you

will experience crashes. This option is also known with the older name

CURLOPT_FILE, the name CURLOPT_WRITEDATA was introduced

in 7.9.7.

CURLOPT_READFUNCTION

Function pointer that should match the following proto-

type: size_t function( void *ptr, size_t size, size_t

nmemb, void *userdata); This function gets called by libcurl as soon as it needs to read data in order to send it to the peer. The data area pointed at by the pointer ptr may be filled with at most size multiplied with nmemb number of bytes. Your function must return the actual number of bytes that you stored in that

memory area. Returning 0 will signal end-of-file to the

library and cause it to stop the current transfer.

If you stop the current transfer by returning 0 "pre-

maturely" (i.e before the server expected it, like when you've said you will upload N bytes and you upload less than N bytes), you may experience that the server "hangs" waiting for the rest of the data that won't libcurl 7.20.0 Last change: 1 Jan 2010 4

libcurl Manual curl_easy_setopt(3)

come.

The read callback may return CURL_READFUNC_ABORT to

stop the current operation immediately, resulting in a

CURLE_ABORTED_BY_CALLBACK error code from the transfer

(Added in 7.12.1) From 7.18.0, the function can return

CURL_READFUNC_PAUSE which then will cause reading from

this connection to become paused. See

curl_easy_pause(3) for further details.

If you set this callback pointer to NULL, or don't set it at all, the default internal read function will be used. It is doing an fread() on the FILE * userdata set

with CURLOPT_READDATA.

CURLOPT_READDATA

Data pointer to pass to the file read function. If you

use the CURLOPT_READFUNCTION option, this is the

pointer you'll get as input. If you don't specify a read callback but instead rely on the default internal read function, this data must be a valid readable FILE *. If you're using libcurl as a win32 DLL, you MUST use a

CURLOPT_READFUNCTION if you set this option.

This option was also known by the older name

CURLOPT_INFILE, the name CURLOPT_READDATA was intro-

duced in 7.9.7.

CURLOPT_IOCTLFUNCTION

Function pointer that should match the

curl_ioctl_callback prototype found in .

This function gets called by libcurl when something

special I/O-related needs to be done that the library

can't do by itself. For now, rewinding the read data stream is the only action it can request. The rewinding of the read data stream may be necessary when doing a

HTTP PUT or POST with a multi-pass authentication

method. (Option added in 7.12.3).

Use CURLOPT_SEEKFUNCTION instead to provide seeking!

CURLOPT_IOCTLDATA

Pass a pointer that will be untouched by libcurl and passed as the 3rd argument in the ioctl callback set

with CURLOPT_IOCTLFUNCTION. (Option added in 7.12.3)

CURLOPT_SEEKFUNCTION

Function pointer that should match the following libcurl 7.20.0 Last change: 1 Jan 2010 5

libcurl Manual curl_easy_setopt(3)

prototype: int function(void *instream, curl_off_t

offset, int origin); This function gets called by lib-

curl to seek to a certain position in the input stream and can be used to fast forward a file in a resumed upload (instead of reading all uploaded bytes with the normal read function/callback). It is also called to rewind a stream when doing a HTTP PUT or POST with a

multi-pass authentication method. The function shall

work like "fseek" or "lseek" and accepted SEEK_SET,

SEEK_CUR and SEEK_END as argument for origin, although

(in 7.18.0) libcurl only passes SEEK_SET. The callback

must return 0 (CURL_SEEKFUNC_OK) on success, 1

(CURL_SEEKFUNC_FAIL) to cause the upload operation to

fail or 2 (CURL_SEEKFUNC_CANTSEEK) to indicate that

while the seek failed, libcurl is free to work around the problem if possible. The latter can sometimes be done by instead reading from the input or similar. If you forward the input arguments directly to "fseek" or "lseek", note that the data type for offset is not

the same as defined for curl_off_t on many systems!

(Option added in 7.18.0)

CURLOPT_SEEKDATA

Data pointer to pass to the file read function. If you

use the CURLOPT_SEEKFUNCTION option, this is the

pointer you'll get as input. If you don't specify a seek callback, NULL is passed. (Option added in 7.18.0)

CURLOPT_SOCKOPTFUNCTION

Function pointer that should match the

curl_sockopt_callback prototype found in .

This function gets called by libcurl after the socket()

call but before the connect() call. The callback's pur-

pose argument identifies the exact purpose for this

particular socket, and currently only one value is sup-

ported: CURLSOCKTYPE_IPCXN for the primary connection

(meaning the control connection in the FTP case). Future versions of libcurl may support more purposes.

It passes the newly created socket descriptor so addi-

tional setsockopt() calls can be done at the user's

discretion. Return 0 (zero) from the callback on suc-

cess. Return 1 from the callback function to signal an unrecoverable error to the library and it will close

the socket and return CURLE_COULDNT_CONNECT. (Option

added in 7.15.6.)

CURLOPT_SOCKOPTDATA

Pass a pointer that will be untouched by libcurl and passed as the first argument in the sockopt callback

set with CURLOPT_SOCKOPTFUNCTION. (Option added in

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CURLOPT_OPENSOCKETFUNCTION

Function pointer that should match the

curl_opensocket_callback prototype found in

. This function gets called by libcurl instead of the socket(2) call. The callback's purpose

argument identifies the exact purpose for this particu-

lar socket, and currently only one value is supported:

CURLSOCKTYPE_IPCXN for the primary connection (meaning

the control connection in the FTP case). Future ver-

sions of libcurl may support more purposes. It passes the resolved peer address as a address argument so the callback can modify the address or refuse to connect at all. The callback function should return the socket or

CURL_SOCKET_BAD in case no connection should be esta-

blished or any error detected. Any additional set-

sockopt(2) calls can be done on the socket at the

user's discretion. CURL_SOCKET_BAD return value from

the callback function will signal an unrecoverable error to the library and it will return

CURLE_COULDNT_CONNECT. This return code can be used

for IP address blacklisting. The default behavior is:

return socket(addr->family, addr->socktype, addr->protocol);

(Option added in 7.17.1.)

CURLOPT_OPENSOCKETDATA

Pass a pointer that will be untouched by libcurl and passed as the first argument in the opensocket callback

set with CURLOPT_OPENSOCKETFUNCTION. (Option added in

7.17.1.)

CURLOPT_PROGRESSFUNCTION

Function pointer that should match the

curl_progress_callback prototype found in

. This function gets called by libcurl instead of its internal equivalent with a frequent interval during operation (roughly once per second or sooner) no matter if data is being transfered or not. Unknown/unused argument values passed to the callback will be set to zero (like if you only download data,

the upload size will remain 0). Returning a non-zero

value from this callback will cause libcurl to abort

the transfer and return CURLE_ABORTED_BY_CALLBACK.

If you transfer data with the multi interface, this function will not be called during periods of idleness unless you call the appropriate libcurl function that performs transfers.

CURLOPT_NOPROGRESS must be set to 0 to make this func-

tion actually get called.

CURLOPT_PROGRESSDATA

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Pass a pointer that will be untouched by libcurl and passed as the first argument in the progress callback

set with CURLOPT_PROGRESSFUNCTION.

CURLOPT_HEADERFUNCTION

Function pointer that should match the following proto-

type: size_t function( void *ptr, size_t size, size_t

nmemb, void *userdata);. This function gets called by libcurl as soon as it has received header data. The header callback will be called once for each header and

only complete header lines are passed on to the call-

back. Parsing headers should be easy enough using this.

The size of the data pointed to by ptr is size multi-

plied with nmemb. Do not assume that the header line is zero terminated! The pointer named userdata is the one

you set with the CURLOPT_WRITEHEADER option. The call-

back function must return the number of bytes actually taken care of. If that amount differs from the amount passed to your function, it'll signal an error to the library. This will abort the transfer and return

CURL_WRITE_ERROR.

If this option is not set, or if it is set to NULL, but

CURLOPT_HEADERDATA (CURLOPT_WRITEHEADER) is set to any-

thing but NULL, the function used to accept response data will be used instead. That is, it will be the

function specified with CURLOPT_WRITEFUNCTION, or if it

is not specified or NULL - the default, stream-writing

function. It's important to note that the callback will be invoked for the headers of all responses received after initiating a request and not just the final response.

This includes all responses which occur during authen-

tication negotiation. If you need to operate on only the headers from the final response, you will need to collect headers in the callback yourself and use HTTP

status lines, for example, to delimit response boun-

daries. Since 7.14.1: When a server sends a chunked encoded transfer, it may contain a trailer. That trailer is identical to a HTTP header and if such a trailer is received it is passed to the application using this callback as well. There are several ways to detect it being a trailer and not an ordinary header: 1) it comes

after the response-body. 2) it comes after the final

header line (CR LF) 3) a Trailer: header among the

response-headers mention what header to expect in the

trailer.

CURLOPT_WRITEHEADER

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(This option is also known as CURLOPT_HEADERDATA) Pass

a pointer to be used to write the header part of the received data to. If you don't use your own callback to take care of the writing, this must be a valid FILE *.

See also the CURLOPT_HEADERFUNCTION option above on how

to set a custom get-all-headers callback.

CURLOPT_DEBUGFUNCTION

Function pointer that should match the following proto-

type: int curl_debug_callback (CURL *, curl_infotype,

char *, size_t, void *); CURLOPT_DEBUGFUNCTION replaces

the standard debug function used when CURLOPT_VERBOSE

is in effect. This callback receives debug information,

as specified with the curl_infotype argument. This

function must return 0. The data pointed to by the

char * passed to this function WILL NOT be zero ter-

minated, but will be exactly of the size as told by the

size_t argument.

Available curl_infotype values:

CURLINFO_TEXT

The data is informational text.

CURLINFO_HEADER_IN

The data is header (or header-like) data received

from the peer.

CURLINFO_HEADER_OUT

The data is header (or header-like) data sent to

the peer.

CURLINFO_DATA_IN

The data is protocol data received from the peer.

CURLINFO_DATA_OUT

The data is protocol data sent to the peer.

CURLOPT_DEBUGDATA

Pass a pointer to whatever you want passed in to your

CURLOPT_DEBUGFUNCTION in the last void * argument. This

pointer is not used by libcurl, it is only passed to the callback.

CURLOPT_SSL_CTX_FUNCTION

This option does only function for libcurl powered by OpenSSL. If libcurl was built against another SSL library, this functionality is absent.

Function pointer that should match the following proto-

type: CURLcode sslctxfun(CURL *curl, void *sslctx, void *parm); This function gets called by libcurl just libcurl 7.20.0 Last change: 1 Jan 2010 9

libcurl Manual curl_easy_setopt(3)

before the initialization of an SSL connection after having processed all other SSL related options to give a last chance to an application to modify the behaviour of openssl's ssl initialization. The sslctx parameter

is actually a pointer to an openssl SSL_CTX. If an

error is returned no attempt to establish a connection is made and the perform operation will return the error

code from this callback function. Set the parm argu-

ment with the CURLOPT_SSL_CTX_DATA option. This option

was introduced in 7.11.0. This function will get called on all new connections made to a server, during the SSL negotiation. The

SSL_CTX pointer will be a new one every time.

To use this properly, a non-trivial amount of knowledge

of the openssl libraries is necessary. For example, using this function allows you to use openssl callbacks to add additional validation code for certificates, and even to change the actual URI of an HTTPS request (example used in the lib509 test case). See also the

example section for a replacement of the key, certifi-

cate and trust file settings.

CURLOPT_SSL_CTX_DATA

Data pointer to pass to the ssl context callback set by

the option CURLOPT_SSL_CTX_FUNCTION, this is the

pointer you'll get as third parameter, otherwise NULL. (Added in 7.11.0)

CURLOPT_CONV_TO_NETWORK_FUNCTION

CURLOPT_CONV_FROM_NETWORK_FUNCTION

CURLOPT_CONV_FROM_UTF8_FUNCTION

Function pointers that should match the following pro-

totype: CURLcode function(char *ptr, size_t length);

These three options apply to non-ASCII platforms only.

They are available only if CURL_DOES_CONVERSIONS was

defined when libcurl was built. When this is the case,

curl_version_info(3) will return the CURL_VERSION_CONV

feature bit set. The data to be converted is in a buffer pointed to by the ptr parameter. The amount of data to convert is indicated by the length parameter. The converted data overlays the input data in the buffer pointed to by the

ptr parameter. CURLE_OK should be returned upon suc-

cessful conversion. A CURLcode return value defined by

curl.h, such as CURLE_CONV_FAILED, should be returned

if an error was encountered. libcurl 7.20.0 Last change: 1 Jan 2010 10

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CURLOPT_CONV_TO_NETWORK_FUNCTION and

CURLOPT_CONV_FROM_NETWORK_FUNCTION convert between the

host encoding and the network encoding. They are used when commands or ASCII data are sent/received over the network.

CURLOPT_CONV_FROM_UTF8_FUNCTION is called to convert

from UTF8 into the host encoding. It is required only for SSL processing. If you set a callback pointer to NULL, or don't set it

at all, the built-in libcurl iconv functions will be

used. If HAVE_ICONV was not defined when libcurl was

built, and no callback has been established, conversion

will return the CURLE_CONV_REQD error code.

If HAVE_ICONV is defined, CURL_ICONV_CODESET_OF_HOST

must also be defined. For example:

#define CURL_ICONV_CODESET_OF_HOST "IBM-1047"

The iconv code in libcurl will default the network and UTF8 codeset names as follows:

#define CURL_ICONV_CODESET_OF_NETWORK "ISO8859-1"

#define CURL_ICONV_CODESET_FOR_UTF8 "UTF-8"

You will need to override these definitions if they are different on your system.

CURLOPT_INTERLEAVEFUNCTION

Function pointer that should match the following proto-

type: size_t function( void *ptr, size_t size, size_t

nmemb, void *userdata). This function gets called by libcurl as soon as it has received interleaved RTP

data. This function gets called for each $ block and

therefore contains exactly one upper-layer protocol

unit (e.g. one RTP packet). Curl writes the inter-

leaved header as well as the included data for each call. The first byte is always an ASCII dollar sign.

The dollar sign is followed by a one byte channel iden-

tifier and then a 2 byte integer length in network byte order. See RFC 2326 Section 10.12 for more information on how RTP interleaving behaves. If unset or set to NULL, curl will use the default write function. Interleaved RTP poses some challeneges for the client application. Since the stream data is sharing the RTSP control connection, it is critical to service the RTP in a timely fashion. If the RTP data is not handled quickly, subsequent response processing may become libcurl 7.20.0 Last change: 1 Jan 2010 11

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unreasonably delayed and the connection may close. The

application may use CURL_RTSPREQ_RECEIVE to service RTP

data when no requests are desired. If the application

makes a request, (e.g. CURL_RTSPREQ_PAUSE) then the

response handler will process any pending RTP data before marking the request as finished. (Added in 7.20.0)

CURLOPT_INTERLEAVEDATA

This is the userdata pointer that will be passed to

CURLOPT_INTERLEAVEFUNCTION when interleaved RTP data is

received. (Added in 7.20.0)

CURLOPT_CHUNK_BGN_FUNCTION

Function pointer that should match the following proto-

type: long function (const void *transfer_info, void

*ptr, int remains). This function gets called by lib-

curl before a part of the stream is going to be transferred (if the transfer supports chunks). This callback makes sense only when using the

CURLOPT_WILDCARDMATCH option for now.

The target of transfer_info parameter is a "feature

depended" structure. For the FTP wildcard download, the

target is curl_fileinfo structure (see curl/curl.h).

The parameter ptr is a pointer given by

CURLOPT_CHUNK_DATA. The parameter remains contains

number of chunks remaining per the transfer. If the feature is not available, the parameter has zero value.

Return CURL_CHUNK_BGN_FUNC_OK if everything is fine,

CURL_CHUNK_BGN_FUNC_SKIP if you want to skip the con-

crete chunk or CURL_CHUNK_BGN_FUNC_FAIL to tell libcurl

to stop if some error occurred. (This was added in 7.21.0)

CURLOPT_CHUNK_END_FUNCTION

Function pointer that should match the following proto-

type: long function(void *ptr). This function gets called by libcurl as soon as a part of the stream has been transferred (or skipped).

Return CURL_CHUNK_END_FUNC_OK if everything is fine or

CURL_CHUNK_END_FUNC_FAIL to tell the lib to stop if

some error occurred. (This was added in 7.21.0)

CURLOPT_CHUNK_DATA

Pass a pointer that will be untouched by libcurl and passed as the ptr argument to the

CURL_CHUNK_BGN_FUNTION and CURL_CHUNK_END_FUNTION.

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CURLOPT_FNMATCH_FUNCTION

Function pointer that should match int function(void

*ptr, const char *pattern, const char *string) proto-

type (see curl/curl.h). It is used internally for the wildcard matching feature.

Return CURL_FNMATCHFUNC_MATCH if pattern matches the

string, CURL_FNMATCHFUNC_NOMATCH if not or

CURL_FNMATCHFUNC_FAIL if an error occurred. (This was

added in 7.21.0)

CURLOPT_FNMATCH_DATA

Pass a pointer that will be untouched by libcurl and passed as the ptr argument to the

CURL_FNMATCH_FUNCTION. (This was added in 7.21.0)

ERROR OPTIONS

CURLOPT_ERRORBUFFER

Pass a char * to a buffer that the libcurl may store human readable error messages in. This may be more helpful than just the return code from

curl_easy_perform. The buffer must be at least

CURL_ERROR_SIZE big. Although this argument is a 'char

*', it does not describe an input string. Therefore the (probably undefined) contents of the buffer is NOT copied by the library. You should keep the associated storage available until libcurl no longer needs it. Failing to do so will cause very odd behavior or even crashes. libcurl will need it until you call

curl_easy_cleanup(3) or you set the same option again

to use a different pointer.

Use CURLOPT_VERBOSE and CURLOPT_DEBUGFUNCTION to better

debug/trace why errors happen. If the library does not return an error, the buffer may not have been touched. Do not rely on the contents in those cases.

CURLOPT_STDERR

Pass a FILE * as parameter. Tell libcurl to use this stream instead of stderr when showing the progress

meter and displaying CURLOPT_VERBOSE data.

CURLOPT_FAILONERROR

A parameter set to 1 tells the library to fail silently if the HTTP code returned is equal to or larger than 400. The default action would be to return the page normally, ignoring that code.

This method is not fail-safe and there are occasions

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where non-successful response codes will slip through,

especially when authentication is involved (response codes 401 and 407). You might get some amounts of headers transferred

before this situation is detected, like when a "100-

continue" is received as a response to a POST/PUT and a 401 or 407 is received immediately afterwards. NETWORK OPTIONS

CURLOPT_URL

The actual URL to deal with. The parameter should be a char * to a zero terminated string. If the given URL lacks the protocol part ("http://" or "ftp://" etc), it will attempt to guess which protocol

to use based on the given host name. If the given pro-

tocol of the set URL is not supported, libcurl will

return on error (CURLE_UNSUPPORTED_PROTOCOL) when you

call curl_easy_perform(3) or curl_multi_perform(3). Use

curl_version_info(3) for detailed info on which proto-

cols are supported.

The string given to CURLOPT_URL must be url-encoded and

follow RFC 2396 (http://curl.haxx.se/rfc/rfc2396.txt). Starting with version 7.20.0, the fragment part of the URI will not be send as part of the path, which was the case previously.

CURLOPT_URL is the only option that must be set before

curl_easy_perform(3) is called.

CURLOPT_PROTOCOLS can be used to limit what protocols

libcurl will use for this transfer, independent of what

libcurl has been compiled to support. That may be use-

ful if you accept the URL from an external source and want to limit the accessibility.

CURLOPT_PROTOCOLS

Pass a long that holds a bitmask of CURLPROTO_*

defines. If used, this bitmask limits what protocols libcurl may use in the transfer. This allows you to

have a libcurl built to support a wide range of proto-

cols but still limit specific transfers to only be allowed to use a subset of them. By default libcurl will accept all protocols it supports. See also

CURLOPT_REDIR_PROTOCOLS. (Added in 7.19.4)

CURLOPT_REDIR_PROTOCOLS

Pass a long that holds a bitmask of CURLPROTO_*

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libcurl may use in a transfer that it follows to in a

redirect when CURLOPT_FOLLOWLOCATION is enabled. This

allows you to limit specific transfers to only be allowed to use a subset of protocols in redirections. By default libcurl will allow all protocols except for

FILE and SCP. This is a difference compared to pre-

7.19.4 versions which unconditionally would follow to all protocols supported. (Added in 7.19.4)

CURLOPT_PROXY

Set HTTP proxy to use. The parameter should be a char * to a zero terminated string holding the host name or dotted IP address. To specify port number in this string, append :[port] to the end of the host name. The proxy string may be prefixed with [protocol]:// since any such prefix will be ignored. The proxy's port number may optionally be specified with the separate option. If not specified, libcurl will default to using

port 1080 for proxies. CURLOPT_PROXYPORT.

When you tell the library to use an HTTP proxy, libcurl will transparently convert operations to HTTP even if you specify an FTP URL etc. This may have an impact on what other features of the library you can use, such as

CURLOPT_QUOTE and similar FTP specifics that don't work

unless you tunnel through the HTTP proxy. Such tunnel-

ing is activated with CURLOPT_HTTPPROXYTUNNEL.

libcurl respects the environment variables http_proxy,

ftp_proxy, all_proxy etc, if any of those are set. The

CURLOPT_PROXY option does however override any possibly

set environment variables. Setting the proxy string to "" (an empty string) will explicitly disable the use of a proxy, even if there is an environment variable set for it.

Since 7.14.1, the proxy host string given in environ-

ment variables can be specified the exact same way as

the proxy can be set with CURLOPT_PROXY, include proto-

col prefix (http://) and embedded user + password.

CURLOPT_PROXYPORT

Pass a long with this option to set the proxy port to connect to unless it is specified in the proxy string

CURLOPT_PROXY.

CURLOPT_PROXYTYPE

Pass a long with this option to set type of the proxy.

Available options for this are CURLPROXY_HTTP,

CURLPROXY_HTTP_1_0 (added in 7.19.4), CURLPROXY_SOCKS4

(added in 7.15.2), CURLPROXY_SOCKS5, CURLPROXY_SOCKS4A

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libcurl Manual curl_easy_setopt(3)

(added in 7.18.0) and CURLPROXY_SOCKS5_HOSTNAME (added

in 7.18.0). The HTTP type is default. (Added in 7.10)

CURLOPT_NOPROXY

Pass a pointer to a zero terminated string. The should

be a comma- separated list of hosts which do not use a

proxy, if one is specified. The only wildcard is a

single * character, which matches all hosts, and effec-

tively disables the proxy. Each name in this list is matched as either a domain which contains the hostname, or the hostname itself. For example, local.com would match local.com, local.com:80, and www.local.com, but not www.notlocal.com. (Added in 7.19.4)

CURLOPT_HTTPPROXYTUNNEL

Set the parameter to 1 to make the library tunnel all operations through a given HTTP proxy. There is a big difference between using a proxy and to tunnel through it. If you don't know what this means, you probably don't want this tunneling option.

CURLOPT_SOCKS5_GSSAPI_SERVICE

Pass a char * as parameter to a string holding the name of the service. The default service name for a SOCKS5

server is rcmd/server-fqdn. This option allows you to

change it. (Added in 7.19.4)

CURLOPT_SOCKS5_GSSAPI_NEC

Pass a long set to 1 to enable or 0 to disable. As part

of the gssapi negotiation a protection mode is nego-

tiated. The rfc1961 says in section 4.3/4.4 it should be protected, but the NEC reference implementation does not. If enabled, this option allows the unprotected exchange of the protection mode negotiation. (Added in 7.19.4).

CURLOPT_INTERFACE

Pass a char * as parameter. This sets the interface name to use as outgoing network interface. The name can be an interface name, an IP address, or a host name.

CURLOPT_LOCALPORT

Pass a long. This sets the local port number of the

socket used for connection. This can be used in combi-

nation with CURLOPT_INTERFACE and you are recommended

to use CURLOPT_LOCALPORTRANGE as well when this is set.

Valid port numbers are 1 - 65535. (Added in 7.15.2)

CURLOPT_LOCALPORTRANGE

Pass a long. This is the number of attempts libcurl should make to find a working local port number. It

starts with the given CURLOPT_LOCALPORT and adds one to

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libcurl Manual curl_easy_setopt(3)

the number for each retry. Setting this to 1 or below will make libcurl do only one try for the exact port number. Port numbers by nature are scarce resources that will be busy at times so setting this value to something too low might cause unnecessary connection setup failures. (Added in 7.15.2)

CURLOPT_DNS_CACHE_TIMEOUT

Pass a long, this sets the timeout in seconds. Name resolves will be kept in memory for this number of seconds. Set to zero to completely disable caching, or

set to -1 to make the cached entries remain forever. By

default, libcurl caches this info for 60 seconds.

The name resolve functions of various libc implementa-

tions don't re-read name server information unless

explicitly told so (for example, by calling

res_init(3)). This may cause libcurl to keep using the

older server even if DHCP has updated the server info, and this may look like a DNS cache issue to the casual

libcurl-app user.

CURLOPT_DNS_USE_GLOBAL_CACHE

Pass a long. If the value is 1, it tells curl to use a global DNS cache that will survive between easy handle

creations and deletions. This is not thread-safe and

this will use a global variable. WARNING: this option is considered obsolete. Stop using it. Switch over to using the share interface instead!

See CURLOPT_SHARE and curl_share_init(3).

CURLOPT_BUFFERSIZE

Pass a long specifying your preferred size (in bytes) for the receive buffer in libcurl. The main point of this would be that the write callback gets called more often and with smaller chunks. This is just treated as a request, not an order. You cannot be guaranteed to actually get the given size. (Added in 7.10) This size is by default set as big as possible

(CURL_MAX_WRITE_SIZE), so it only makes sense to use

this option if you want it smaller.

CURLOPT_PORT

Pass a long specifying what remote port number to con-

nect to, instead of the one specified in the URL or the default port for the used protocol.

CURLOPT_TCP_NODELAY

Pass a long specifying whether the TCP_NODELAY option

should be set or cleared (1 = set, 0 = clear). The libcurl 7.20.0 Last change: 1 Jan 2010 17

libcurl Manual curl_easy_setopt(3)

option is cleared by default. This will have no effect after the connection has been established. Setting this option will disable TCP's Nagle algorithm. The purpose of this algorithm is to try to minimize the number of small packets on the network (where "small

packets" means TCP segments less than the Maximum Seg-

ment Size (MSS) for the network). Maximizing the amount of data sent per TCP segment is good because it amortizes the overhead of the send. However, in some cases (most notably telnet or rlogin) small segments may need to be sent without delay. This is less efficient than sending larger amounts of data

at a time, and can contribute to congestion on the net-

work if overdone.

CURLOPT_ADDRESS_SCOPE

Pass a long specifying the scope_id value to use when

connecting to IPv6 link-local or site-local addresses.

(Added in 7.19.0)

NAMES and PASSWORDS OPTIONS (Authentication)

CURLOPT_NETRC

This parameter controls the preference of libcurl between using user names and passwords from your ~/.netrc file, relative to user names and passwords in

the URL supplied with CURLOPT_URL.

libcurl uses a user name (and supplied or prompted

password) supplied with CURLOPT_USERPWD in preference

to any of the options controlled by this parameter. Pass a long, set to one of the values described below.

CURL_NETRC_OPTIONAL

The use of your ~/.netrc file is optional, and information in the URL is to be preferred. The file will be scanned for the host and user name (to find the password only) or for the host only, to find the first user name and password after

that machine, which ever information is not speci-

fied in the URL. Undefined values of the option will have this effect.

CURL_NETRC_IGNORED

The library will ignore the file and use only the information in the URL. This is the default. libcurl 7.20.0 Last change: 1 Jan 2010 18

libcurl Manual curl_easy_setopt(3)

CURL_NETRC_REQUIRED

This value tells the library that use of the file is required, to ignore the information in the URL, and to search the file for the host only. Only machine name, user name and password are taken into account (init macros and similar things aren't supported).

libcurl does not verify that the file has the correct pro-

perties set (as the standard Unix ftp client does). It should only be readable by user.

CURLOPT_NETRC_FILE

Pass a char * as parameter, pointing to a zero ter-

minated string containing the full path name to the file you want libcurl to use as .netrc file. If this

option is omitted, and CURLOPT_NETRC is set, libcurl

will attempt to find a .netrc file in the current user's home directory. (Added in 7.10.9)

CURLOPT_USERPWD

Pass a char * as parameter, which should be [user name]:[password] to use for the connection. Use

CURLOPT_HTTPAUTH to decide the authentication method.

When using NTLM, you can set the domain by prepending it to the user name and separating the domain and name with a forward (/) or backward slash (\). Like this: "domain/user:password" or "domain\user:password". Some HTTP servers (on Windows) support this style even for Basic authentication.

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 lib-

curl follows locations to other hosts it will not send the user and password to those. This is enforced to prevent accidental information leakage.

CURLOPT_PROXYUSERPWD

Pass a char * as parameter, which should be [user name]:[password] to use for the connection to the HTTP

proxy. Use CURLOPT_PROXYAUTH to decide the authentica-

tion method.

CURLOPT_USERNAME

Pass a char * as parameter, which should be pointing to the zero terminated user name to use for the transfer.

CURLOPT_USERNAME sets the user name to be used in pro-

tocol authentication. You should not use this option libcurl 7.20.0 Last change: 1 Jan 2010 19

libcurl Manual curl_easy_setopt(3)

together with the (older) CURLOPT_USERPWD option.

In order to specify the password to be used in conjunc-

tion with the user name use the CURLOPT_PASSWORD

option. (Added in 7.19.1)

CURLOPT_PASSWORD

Pass a char * as parameter, which should be pointing to the zero terminated password to use for the transfer.

The CURLOPT_PASSWORD option should be used in conjunc-

tion with the CURLOPT_USERNAME option. (Added in

7.19.1)

CURLOPT_PROXYUSERNAME

Pass a char * as parameter, which should be pointing to the zero terminated user name to use for the transfer while connecting to Proxy.

The CURLOPT_PROXYUSERNAME option should be used in same

way as the CURLOPT_PROXYUSERPWD is used. In comparison

to CURLOPT_PROXYUSERPWD the CURLOPT_PROXYUSERNAME

allows the username to contain a colon, like in the following example: "sip:user@example.com". The

CURLOPT_PROXYUSERNAME option is an alternative way to

set the user name while connecting to Proxy. There is no meaning to use it together with the

CURLOPT_PROXYUSERPWD option.

In order to specify the password to be used in conjunc-

tion with the user name use the CURLOPT_PROXYPASSWORD

option. (Added in 7.19.1)

CURLOPT_PROXYPASSWORD

Pass a char * as parameter, which should be pointing to the zero terminated password to use for the transfer while connecting to Proxy.

The CURLOPT_PROXYPASSWORD option should be used in con-

junction with the CURLOPT_PROXYUSERNAME option. (Added

in 7.19.1)

CURLOPT_HTTPAUTH

Pass a long as parameter, which is set to a bitmask, to tell libcurl which 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 which authentication methods it supports and then pick the best one you allow it to use. For some

methods, this will induce an extra network round-trip.

Set the actual name and password with the

CURLOPT_USERPWD option or with the CURLOPT_USERNAME and

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the CURLOPT_USERPASSWORD options. (Added in 7.10.6)

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 sends the user name and password over the network in plain text, easily captured by others.

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.

CURLAUTH_DIGEST_IE

HTTP Digest authentication with an IE flavor. 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. The IE flavor is simply that libcurl will use a special "quirk" that IE is known to have used before version 7 and that some servers require the client to use. (This define was added in 7.19.3)

CURLAUTH_GSSNEGOTIATE

HTTP GSS-Negotiate authentication. The GSS-

Negotiate (also known as plain "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 also be used along with other authentication methods. For more

information see IETF draft draft-brezak-spnego-

http-04.txt.

You need to build libcurl with a suitable GSS-API

library for this to work.

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 eaves-

dropped. You need to build libcurl with OpenSSL support for this option to work, or build libcurl on Windows.

CURLAUTH_ANY

This is a convenience macro that sets all bits and thus makes libcurl pick any it finds suitable. libcurl 7.20.0 Last change: 1 Jan 2010 21

libcurl Manual curl_easy_setopt(3)

libcurl will automatically select the one it finds most secure.

CURLAUTH_ANYSAFE

This is a convenience macro that sets all bits except Basic and thus makes libcurl pick any it finds suitable. libcurl will automatically select the one it finds most secure.

CURLOPT_PROXYAUTH

Pass a long as parameter, which is set to a bitmask, to tell libcurl which 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. For some methods,

this will induce an extra network round-trip. Set the

actual name and password with the CURLOPT_PROXYUSERPWD

option. The bitmask can be constructed by or'ing

together the bits listed above for the CURLOPT_HTTPAUTH

option. As of this writing, only Basic, Digest and NTLM work. (Added in 7.10.7) HTTP OPTIONS

CURLOPT_AUTOREFERER

Pass a parameter set to 1 to enable this. When enabled, libcurl will automatically set the Referer: field in requests where it follows a Location: redirect.

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: identity, which does nothing, deflate which requests the server to compress its response using the zlib algorithm, and gzip 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.

CURLOPT_FOLLOWLOCATION

A parameter set to 1 tells the library to follow any Location: header that the server sends as part of an HTTP header.

This means that the library will re-send the same

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libcurl Manual curl_easy_setopt(3)

request on the new location and follow new Location: headers all the way until no more such headers are

returned. CURLOPT_MAXREDIRS can be used to limit the

number of redirects libcurl will follow. Since 7.19.4, libcurl can limit what protocols it will automatically follow. The accepted protocols are set

with CURLOPT_REDIR_PROTOCOLS and it excludes the FILE

protocol by default.

CURLOPT_UNRESTRICTED_AUTH

A parameter set to 1 tells the library it can continue to send authentication (user+password) when following locations, even when hostname changed. This option is

meaningful only when setting CURLOPT_FOLLOWLOCATION.

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

(CURLE_TOO_MANY_REDIRECTS). This option only makes

sense if the CURLOPT_FOLLOWLOCATION is used at the same

time. Added in 7.15.1: Setting the limit to 0 will

make libcurl refuse any redirect. Set it to -1 for an

infinite number of redirects (which is the default)

CURLOPT_POSTREDIR

Pass a bitmask to control how libcurl acts on redirects after POSTs that get a 301 or 302 response back. A

parameter with bit 0 set (value CURL_REDIR_POST_301)

tells the library to respect RFC 2616/10.3.2 and not convert POST requests into GET requests when following a 301 redirection. Setting bit 1 (value

CURL_REDIR_POST_302) makes libcurl maintain the request

method after a 302 redirect. CURL_REDIR_POST_ALL is a

convenience define that sets both bits.

The non-RFC behaviour is ubiquitous in web browsers, so

the library does the conversion by default to maintain consistency. However, a server may require a POST to remain a POST after such a redirection. This option is

meaningful only when setting CURLOPT_FOLLOWLOCATION.

(Added in 7.17.1) (This option was known as

CURLOPT_POST301 up to 7.19.0 as it only supported the

301 way before then)

CURLOPT_PUT

A parameter set to 1 tells the library to use HTTP PUT to transfer data. The data should be set with

CURLOPT_READDATA and CURLOPT_INFILESIZE.

This option is deprecated and starting with version libcurl 7.20.0 Last change: 1 Jan 2010 23

libcurl Manual curl_easy_setopt(3)

7.12.1 you should instead use CURLOPT_UPLOAD.

CURLOPT_POST

A parameter set to 1 tells the library to do a regular HTTP post. This will also make the library use a

"Content-Type: application/x-www-form-urlencoded"

header. (This is by far the most commonly used POST method).

Use one of CURLOPT_POSTFIELDS or CURLOPT_COPYPOSTFIELDS

options to specify what data to post and

CURLOPT_POSTFIELDSIZE or CURLOPT_POSTFIELDSIZE_LARGE to

set the data size. Optionally, you can provide data to POST using the

CURLOPT_READFUNCTION and CURLOPT_READDATA options but

then you must make sure to not set CURLOPT_POSTFIELDS

to anything but NULL. When providing data with a call-

back, you must transmit it using chunked transfer-

encoding or you must set the size of the data with the

CURLOPT_POSTFIELDSIZE or CURLOPT_POSTFIELDSIZE_LARGE

option. To enable chunked encoding, you simply pass in

the appropriate Transfer-Encoding header, see the

post-callback.c example.

You can override the default POST Content-Type: header

by setting your own with CURLOPT_HTTPHEADER.

Using POST with HTTP 1.1 implies the use of a "Expect:

100-continue" header. You can disable this header with

CURLOPT_HTTPHEADER as usual.

If you use POST to a HTTP 1.1 server, you can send data without knowing the size before starting the POST if you use chunked encoding. You enable this by adding a

header like "Transfer-Encoding: chunked" with

CURLOPT_HTTPHEADER. With HTTP 1.0 or without chunked

transfer, you must specify the size in the request.

When setting CURLOPT_POST to 1, it will automatically

set CURLOPT_NOBODY to 0 (since 7.14.1).

If you issue a POST request and then want to make a

HEAD or GET using the same re-used handle, you must

explicitly set the new request type using

CURLOPT_NOBODY or CURLOPT_HTTPGET or similar.

CURLOPT_POSTFIELDS

Pass a void * as parameter, which should be the full data to post in an HTTP POST operation. You must make sure that the data is formatted the way you want the server to receive it. libcurl will not convert or libcurl 7.20.0 Last change: 1 Jan 2010 24

libcurl Manual curl_easy_setopt(3)

encode it for you. Most web servers will assume this

data to be url-encoded.

The pointed data are NOT copied by the library: as a consequence, they must be preserved by the calling application until the transfer finishes.

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.

If you want to do a zero-byte POST, you need to set

CURLOPT_POSTFIELDSIZE explicitly to zero, as simply

setting CURLOPT_POSTFIELDS to NULL or "" just effec-

tively disables the sending of the specified string. libcurl will instead assume that you'll send the POST data using the read callback! Using POST with HTTP 1.1 implies the use of a "Expect:

100-continue" header. You can disable this header with

CURLOPT_HTTPHEADER as usual.

To make multipart/formdata posts (aka RFC2388-posts),

check out the CURLOPT_HTTPPOST option.

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 -1, the library will use

strlen() to get the size.

CURLOPT_POSTFIELDSIZE_LARGE

Pass a curl_off_t as parameter. Use this to set the

size of the CURLOPT_POSTFIELDS data to prevent libcurl

from doing strlen() on the data to figure out the size. This is the large file version of the

CURLOPT_POSTFIELDSIZE option. (Added in 7.11.1)

CURLOPT_COPYPOSTFIELDS

Pass a char * as parameter, which should be the full data to post in an HTTP POST operation. It behaves as

the CURLOPT_POSTFIELDS option, but the original data

are copied by the library, allowing the application to overwrite the original data after setting this option. Because data are copied, care must be taken when using

this option in conjunction with CURLOPT_POSTFIELDSIZE

or CURLOPT_POSTFIELDSIZE_LARGE: If the size has not

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libcurl Manual curl_easy_setopt(3)

been set prior to CURLOPT_COPYPOSTFIELDS, the data are

assumed to be a NUL-terminated string; else the stored

size informs the library about the data byte count to copy. In any case, the size must not be changed after

CURLOPT_COPYPOSTFIELDS, unless another

CURLOPT_POSTFIELDS or CURLOPT_COPYPOSTFIELDS option is

issued. (Added in 7.17.1)

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

curl_httppost structs as parameter. The easiest way to

create such a list, is to use curl_formadd(3) as docu-

mented. The data in this list must remain intact until you close this curl handle again with

curl_easy_cleanup(3).

Using POST with HTTP 1.1 implies the use of a "Expect:

100-continue" header. You can disable this header with

CURLOPT_HTTPHEADER as usual.

When setting CURLOPT_HTTPPOST, it will automatically

set CURLOPT_NOBODY to 0 (since 7.14.1).

CURLOPT_REFERER

Pass a pointer to a zero terminated string as parame-

ter. 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 CURLOPT_HTTPHEADER.

CURLOPT_USERAGENT

Pass a pointer to a zero terminated string as parame-

ter. 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 CURLOPT_HTTPHEADER.

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 struct curl_slist

structs properly filled in. Use curl_slist_append(3) to

create the list and curl_slist_free_all(3) 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 content as in 'Accept:' (no data on the right side of

the colon), the internally used header will get dis-

abled. Thus, using this option you can add new headers, replace internal headers and remove internal headers. libcurl 7.20.0 Last change: 1 Jan 2010 26

libcurl Manual curl_easy_setopt(3)

To add a header with no content, make the content be two quotes: "". 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 (containing the method, usually a GET or POST) is not a header and cannot be replaced using this option. Only the lines following

the request-line are headers. Adding this method line

in this list of headers will only cause your request to send an invalid header. Pass a NULL to this to reset back to no custom headers. The most commonly replaced headers have "shortcuts" in

the options CURLOPT_COOKIE, CURLOPT_USERAGENT and

CURLOPT_REFERER.

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 exam-

ple, 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

curl_slist_append(3) to create the list and

curl_slist_free_all(3) to clean up an entire list.

The alias itself is not parsed for any version strings. Before libcurl 7.16.3, Libcurl used the value set by

option CURLOPT_HTTP_VERSION, but starting with 7.16.3

the protocol is assumed to match HTTP 1.0 when an alias matched.

CURLOPT_COOKIE

Pass a pointer to a zero terminated string as parame-

ter. 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 CON-

TENTS is what the cookie should contain. If you need to set multiple cookies, you need to set them all using a single option and thus you need to concatenate them all in one single string. Set multiple cookies in one string like this: "name1=content1; name2=content2;" etc. libcurl 7.20.0 Last change: 1 Jan 2010 27

libcurl Manual curl_easy_setopt(3)

This option sets the cookie header explictly in the outgoing request(s). If multiple requests are done due to authentication, followed redirections or similar, they will all get this cookie passed on. Using this option multiple times will only make the latest string override the previous ones.

CURLOPT_COOKIEFILE

Pass a pointer to a zero terminated string as parame-

ter. 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 or by passing the

empty string (""), this option will enable cookies for this curl handle, making it understand and parse received cookies and then use matching cookies in future requests. If you use this option multiple times, you just add more files to read. Subsequent files will add more cookies.

CURLOPT_COOKIEJAR

Pass a file name as char *, zero terminated. This will make libcurl write all internally known cookies to the

specified file when curl_easy_cleanup(3) 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 ses-

sion, so if you for example follow a location it will make matching cookies get sent accordingly. If the cookie jar file can't be created or written to

(when the curl_easy_cleanup(3) 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 feed-

back you get about this possibly lethal situation.

CURLOPT_COOKIESESSION

Pass a long set to 1 to mark this as a new cookie "ses-

sion". It will force libcurl to ignore all cookies it is about to load that are "session cookies" from the previous session. By default, libcurl always stores and loads all cookies, independent if they are session cookies or not. Session cookies are cookies without expiry date and they are meant to be alive and existing for this "session" only. libcurl 7.20.0 Last change: 1 Jan 2010 28

libcurl Manual curl_easy_setopt(3)

CURLOPT_COOKIELIST

Pass a char * to a cookie string. Cookie can be either

in Netscape / Mozilla format or just regular HTTP-style

header (Set-Cookie: ...) format. If cURL cookie engine

was not enabled it will enable its cookie engine. Passing a magic string "ALL" will erase all cookies known by cURL. (Added in 7.14.1) Passing the special string "SESS" will only erase all session cookies known by cURL. (Added in 7.15.4) Passing the special string "FLUSH" will write all cookies known by cURL to the

file specified by CURLOPT_COOKIEJAR. (Added in 7.17.1)

CURLOPT_HTTPGET

Pass a long. If the long is 1, this forces the HTTP request to get back to GET. Usable if a POST, HEAD, PUT, or a custom request has been used previously using the same curl handle.

When setting CURLOPT_HTTPGET to 1, it will automati-

cally set CURLOPT_NOBODY to 0 (since 7.14.1).

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 rea-

son.

CURL_HTTP_VERSION_NONE

We don't care about what version the library uses. libcurl will use whatever it thinks fit.

CURL_HTTP_VERSION_1_0

Enforce HTTP 1.0 requests.

CURL_HTTP_VERSION_1_1

Enforce HTTP 1.1 requests.

CURLOPT_IGNORE_CONTENT_LENGTH

Ignore the Content-Length header. This is useful for

Apache 1.x (and similar servers) which will report incorrect content length for files over 2 gigabytes. If

this option is used, curl will not be able to accu-

rately report progress, and will simply stop the down-

load when the server ends the connection. (added in 7.14.1)

CURLOPT_HTTP_CONTENT_DECODING

Pass a long to tell libcurl how to act on content

decoding. If set to zero, content decoding will be dis-

abled. If set to 1 it is enabled. Libcurl has no default content decoding but requires you to use

CURLOPT_ENCODING for that. (added in 7.16.2)

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libcurl Manual curl_easy_setopt(3)

CURLOPT_HTTP_TRANSFER_DECODING

Pass a long to tell libcurl how to act on transfer decoding. If set to zero, transfer decoding will be disabled, if set to 1 it is enabled (default). libcurl does chunked transfer decoding by default unless this option is set to zero. (added in 7.16.2) SMTP OPTIONS

CURLOPT_MAIL_FROM

Pass a pointer to a zero terminated string as parame-

ter. It will be used to specify the sender address in a mail when sending an SMTP mail with libcurl. (Added in 7.20.0)

CURLOPT_MAIL_RCPT

Pass a pointer to a linked list of recipients to pass to the server in your SMTP mail request. The linked

list should be a fully valid list of struct curl_slist

structs properly filled in. Use curl_slist_append(3) to

create the list and curl_slist_free_all(3) to clean up

an entire list. Each recipient in SMTP lingo is specified with angle brackets (<>), but should you not use an angle bracket

as first letter libcurl will assume you provide a sin-

gle email address only and enclose that with angle brackets for you. (Added in 7.20.0) TFTP OPTIONS

CURLOPT_TFTP_BLKSIZE

Specify block size to use for TFTP data transmission.

Valid range as per RFC 2348 is 8-65464 bytes. The

default of 512 bytes will be used if this option is not specified. The specified block size will only be used pending support by the remote server. If the server does not return an option acknowledgement or returns an option acknowledgement with no blksize, the default of 512 bytes will be used. (added in 7.19.4) FTP OPTIONS

CURLOPT_FTPPORT

Pass a pointer to a zero terminated string as parame-

ter. 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, a network interface name (under Unix) or just a

'-' symbol to let the library use your system's default

IP address. Default FTP operations are passive, and libcurl 7.20.0 Last change: 1 Jan 2010 30

libcurl Manual curl_easy_setopt(3)

thus won't use PORT. The address can be followed by a ':' to specify a port,

optionally followed by a '-' to specify a port range.

If the port specified is 0, the operating system will pick a free port. If a range is provided and all ports in the range are not available, libcurl will report

CURLE_FTP_PORT_FAILED for the handle. Invalid

port/range settings are ignored. IPv6 addresses fol-

lowed by a port or portrange have to be in brackets. IPv6 addresses without port/range specifier can be in brackets. (added in 7.19.5) Examples with specified ports: eth0:0

192.168.1.2:32000-33000

curl.se:32123

[::1]:1234-4567

You disable PORT again and go back to using the passive version by setting this option to NULL.

CURLOPT_QUOTE

Pass a pointer to a linked list of FTP or SFTP commands to pass to the server prior to your FTP request. This will be done before any other commands are issued (even before the CWD command for FTP). The linked list should

be a fully valid list of 'struct curl_slist' structs

properly filled in with text strings. Use

curl_slist_append(3) to append strings (commands) to

the list, and clear the entire list afterwards with

curl_slist_free_all(3). Disable this operation again by

setting a NULL to this option. The set of valid FTP commands depends on the server (see RFC959 for a list of mandatory commands). The valid SFTP commands are: chgrp, chmod, chown, ln, mkdir, pwd, rename, rm, rmdir, symlink (see curl(1)) (SFTP support added in 7.16.3)

CURLOPT_POSTQUOTE

Pass a pointer to a linked list of FTP or SFTP commands to pass to the server after your FTP transfer request. The commands will only be run if no error occurred. The linked list should be a fully valid list of struct

curl_slist structs properly filled in as described for

CURLOPT_QUOTE. Disable this operation again by setting

a NULL to this option.

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 libcurl 7.20.0 Last change: 1 Jan 2010 31

libcurl Manual curl_easy_setopt(3)

curl_slist structs properly filled in as described for

CURLOPT_QUOTE. Disable this operation again by setting

a NULL to this option. Before version 7.15.6, if you

also set CURLOPT_NOBODY to 1, this option didn't work.

CURLOPT_DIRLISTONLY

A parameter set to 1 tells the library to just list the names of files in a directory, instead of doing a full directory listing that would include file sizes, dates etc. This works for FTP and SFTP URLs. This causes an FTP NLST command to be sent on an FTP server. Beware that some FTP servers list only files

in their response to NLST; they might not include sub-

directories and symbolic links.

(This option was known as CURLOPT_FTPLISTONLY up to

7.16.4)

CURLOPT_APPEND

A parameter set to 1 tells the library to append to the

remote file instead of overwrite it. This is only use-

ful when uploading to an FTP site.

(This option was known as CURLOPT_FTPAPPEND up to

7.16.4)

CURLOPT_FTP_USE_EPRT

Pass a long. If the value is 1, it tells curl to use

the EPRT (and LPRT) command when doing active FTP down-

loads (which is enabled by CURLOPT_FTPPORT). Using EPRT

means that it will first attempt to use EPRT and then LPRT before using PORT, but if you pass zero to this option, it will not try using EPRT or LPRT, only plain PORT. (Added in 7.10.5) If the server is an IPv6 host, this option will have no effect as of 7.12.3.

CURLOPT_FTP_USE_EPSV

Pass a long. If the value is 1, it tells curl to use the EPSV command when doing passive FTP downloads (which it always does by default). Using EPSV means that it will first attempt to use EPSV before using PASV, but if you pass zero to this option, it will not try using EPSV, only plain PASV. If the server is an IPv6 host, this option will have no effect as of 7.12.3.

CURLOPT_FTP_USE_PRET

Pass a long. If the value is 1, it tells curl to send a libcurl 7.20.0 Last change: 1 Jan 2010 32

libcurl Manual curl_easy_setopt(3)

PRET command before PASV (and EPSV). Certain FTP

servers, mainly drftpd, require this non-standard com-

mand for directory listings as well as up and downloads in PASV mode. Has no effect when using the active FTP transfers mode. (Added in 7.20.0)

CURLOPT_FTP_CREATE_MISSING_DIRS

Pass a long. If the value is 1, curl will attempt to create any remote directory that it fails to CWD into. CWD is the command that changes working directory. (Added in 7.10.7)

This setting also applies to SFTP-connections. curl

will attempt to create the remote directory if it can't

obtain a handle to the target-location. The creation

will fail if a file of the same name as the directory to create already exists or lack of permissions prevents creation. (Added in 7.16.3) Starting with 7.19.4, you can also set this value to 2, which will make libcurl retry the CWD command again if the subsequent MKD command fails. This is especially useful if you're doing many simultanoes connections against the same server and they all have this option enabled, as then CWD may first fail but then another connection does MKD before this connection and thus MKD fails but trying CWD works! 7.19.4 also introduced the

CURLFTP_CREATE_DIR and CURLFTP_CREATE_DIR_RETRY enum

names for these arguments.

Before version 7.19.4, libcurl will simply ignore argu-

ments set to 2 and act as if 1 was selected.

CURLOPT_FTP_RESPONSE_TIMEOUT

Pass a long. Causes curl to set a timeout period (in seconds) on the amount of time that the server is allowed to take in order to generate a response message for a command before the session is considered hung.

While curl is waiting for a response, this value over-

rides CURLOPT_TIMEOUT. It is recommended that if used

in conjunction with CURLOPT_TIMEOUT, you set

CURLOPT_FTP_RESPONSE_TIMEOUT to a value smaller than

CURLOPT_TIMEOUT. (Added in 7.10.8)

CURLOPT_FTP_ALTERNATIVE_TO_USER

Pass a char * as parameter, pointing to a string which will be used to authenticate if the usual FTP "USER user" and "PASS password" negotiation fails. This is currently only known to be required when connecting to Tumbleweed's Secure Transport FTPS server using client certificates for authentication. (Added in 7.15.5) libcurl 7.20.0 Last change: 1 Jan 2010 33

libcurl Manual curl_easy_setopt(3)

CURLOPT_FTP_SKIP_PASV_IP

Pass a long. If set to 1, it instructs libcurl to not

use the IP address the server suggests in its 227-

response to libcurl's PASV command when libcurl con-

nects the data connection. Instead libcurl will re-use

the same IP address it already uses for the control connection. But it will use the port number from the

227-response. (Added in 7.14.2)

This option has no effect if PORT, EPRT or EPSV is used instead of PASV.

CURLOPT_USE_SSL

Pass a long using one of the values from below, to make libcurl use your desired level of SSL for the FTP transfer. (Added in 7.11.0)

(This option was known as CURLOPT_FTP_SSL up to 7.16.4,

and the constants were known as CURLFTPSSL_*)

CURLUSESSL_NONE

Don't attempt to use SSL.

CURLUSESSL_TRY

Try using SSL, proceed as normal otherwise.

CURLUSESSL_CONTROL

Require SSL for the control connection or fail

with CURLE_USE_SSL_FAILED.

CURLUSESSL_ALL

Require SSL for all communication or fail with

CURLE_USE_SSL_FAILED.

CURLOPT_FTPSSLAUTH

Pass a long using one of the values from below, to alter how libcurl issues "AUTH TLS" or "AUTH SSL" when

FTP over SSL is activated (see CURLOPT_USE_SSL). (Added

in 7.12.2)

CURLFTPAUTH_DEFAULT

Allow libcurl to decide.

CURLFTPAUTH_SSL

Try "AUTH SSL" first, and only if that fails try "AUTH TLS".

CURLFTPAUTH_TLS

Try "AUTH TLS" first, and only if that fails try "AUTH SSL".

CURLOPT_FTP_SSL_CCC

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libcurl Manual curl_easy_setopt(3)

If enabled, this option makes libcurl use CCC (Clear

Command Channel). It shuts down the SSL/TLS layer after

authenticating. The rest of the control channel commun-

ication will be unencrypted. This allows NAT routers to follow the FTP transaction. Pass a long using one of the values below. (Added in 7.16.1)

CURLFTPSSL_CCC_NONE

Don't attempt to use CCC.

CURLFTPSSL_CCC_PASSIVE

Do not initiate the shutdown, but wait for the server to do it. Do not send a reply.

CURLFTPSSL_CCC_ACTIVE

Initiate the shutdown and wait for a reply.

CURLOPT_FTP_ACCOUNT

Pass a pointer to a zero-terminated string (or NULL to

disable). When an FTP server asks for "account data" after user name and password has been provided, this data is sent off using the ACCT command. (Added in 7.13.0)

CURLOPT_FTP_FILEMETHOD

Pass a long that should have one of the following values. This option controls what method libcurl should use to reach a file on a FTP(S) server. The argument should be one of the following alternatives:

CURLFTPMETHOD_MULTICWD

libcurl does a single CWD operation for each path part in the given URL. For deep hierarchies this means many commands. This is how RFC1738 says it should be done. This is the default but the slowest behavior.

CURLFTPMETHOD_NOCWD

libcurl does no CWD at all. libcurl will do SIZE, RETR, STOR etc and give a full path to the server for all these commands. This is the fastest behavior.

CURLFTPMETHOD_SINGLECWD

libcurl does one CWD with the full target direc-

tory and then operates on the file "normally" (like in the multicwd case). This is somewhat more standards compliant than 'nocwd' but without the full penalty of 'multicwd'. (Added in 7.15.1) libcurl 7.20.0 Last change: 1 Jan 2010 35

libcurl Manual curl_easy_setopt(3)

RTSP OPTIONS

CURLOPT_RTSP_REQUEST

Tell libcurl what kind of RTSP request to make. Pass one of the following RTSP enum values. Unless noted

otherwise, commands require the Session ID to be ini-

tialized. (Added in 7.20.0)

CURL_RTSPREQ_OPTIONS

Used to retrieve the available methods of the server. The application is responsbile for parsing and obeying the response. (The session ID is not needed for this method.) (Added in 7.20.0)

CURL_RTSPREQ_DESCRIBE

Used to get the low level description of a stream.

The application should note what formats it under-

stands in the 'Accept:' header. Unless set manu-

ally, libcurl will automatically fill in 'Accept:

application/sdp'. Time-condition headers will be

added to Describe requests if the

CURLOPT_TIMECONDITION option is active. (The ses-

sion ID is not needed for this method) (Added in 7.20.0)

CURL_RTSPREQ_ANNOUNCE

When sent by a client, this method changes the description of the session. For example, if a client is using the server to record a meeting, the client can use Announce to inform the server

of all the meta-information about the session.

ANNOUNCE acts like an HTTP PUT or POST just like

CURL_RTSPREQ_SET_PARAMETER (Added in 7.20.0)

CURL_RTSPREQ_SETUP

Setup is used to initialize the transport layer for the session. The application must set the desired Transport options for a session by using

the CURLOPT_RTSP_TRANSPORT option prior to calling

setup. If no session ID is currently set with

CURLOPT_RTSP_SESSION_ID, libcurl will extract and

use the session ID in the response to this request. (The session ID is not needed for this method). (Added in 7.20.0)

CURL_RTSPREQ_PLAY

Send a Play command to the server. Use the

CURLOPT_RANGE option to modify the playback time

(e.g. 'npt=10-15'). (Added in 7.20.0)

CURL_RTSPREQ_PAUSE

Send a Pause command to the server. Use the

CURLOPT_RANGE option with a single value to

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libcurl Manual curl_easy_setopt(3)

indicate when the stream should be halted. (e.g. npt='25') (Added in 7.20.0)

CURL_RTSPREQ_TEARDOWN

This command terminates an RTSP session. Simply closing a connection does not terminate the RTSP

session since it is valid to control an RTSP ses-

sion over different connections. (Added in 7.20.0)

CURL_RTSPREQ_GET_PARAMETER

Retrieve a parameter from the server. By default,

libcurl will automatically include a Content-Type:

text/parameters header on all non-empty requests

unless a custom one is set. GET_PARAMETER acts

just like an HTTP PUT or POST (see

CURL_RTSPREQ_SET_PARAMETER). Applications wishing

to send a heartbeat message (e.g. in the presence

of a server-specified timeout) should send use an

empty GET_PARAMETER request. (Added in 7.20.0)

CURL_RTSPREQ_SET_PARAMETER

Set a parameter on the server. By default, libcurl

will automatically include a Content-Type:

text/parameters header unless a custom one is set.

The interaction with SET_PARAMTER is much like an

HTTP PUT or POST. An application may either use

CURLOPT_UPLOAD with CURLOPT_READDATA like an HTTP

PUT, or it may use CURLOPT_POSTFIELDS like an HTTP

POST. No chunked transfers are allowed, so the

application must set the CURLOPT_INFILESIZE in the

former and CURLOPT_POSTFIELDSIZE in the latter.

Also, there is no use of multi-part POSTs within

RTSP. (Added in 7.20.0)

CURL_RTSPREQ_RECORD

Used to tell the server to record a session. Use

the CURLOPT_RANGE option to modify the record

time. (Added in 7.20.0)

CURL_RTSPREQ_RECEIVE

This is a special request because it does not send any data to the server. The application may call this function in order to receive interleaved RTP data. It will return after processing one read buffer of data in order to give the application a chance to run. (Added in 7.20.0)

CURLOPT_RTSP_SESSION_ID

Pass a char * as a parameter to set the value of the current RTSP Session ID for the handle. Useful for

resuming an in-progress session. Once this value is set

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libcurl Manual curl_easy_setopt(3)

to any non-NULL value, libcurl will return

CURLE_RTSP_SESSION_ERROR if ID received from the server

does not match. If unset (or set to NULL), libcurl will automatically set the ID the first time the server sets it in a response. (Added in 7.20.0)

CURLOPT_RTSP_STREAM_URI

Set the stream URI to operate on by passing a char * . For example, a single session may be controlling rtsp://foo/twister/audio and rtsp://foo/twister/video and the application can switch to the appropriate stream using this option. If unset, libcurl will

default to operating on generic server options by pass-

ing '*' in the place of the RTSP Stream URI. This

option is distinct from CURLOPT_URL. When working with

RTSP, the CURLOPT_STREAM_URI indicates what URL to send

to the server in the request header while the

CURLOPT_URL indicates where to make the connection to.

(e.g. the CURLOPT_URL for the above examples might be

set to rtsp://foo/twister (Added in 7.20.0)

CURLOPT_RTSP_TRANSPORT

Pass a char * to tell libcurl what to pass for the Transport: header for this RTSP session. This is mainly a convenience method to avoid needing to set a custom

Transport: header for every SETUP request. The applica-

tion must set a Transport: header before issuing a SETUP request. (Added in 7.20.0)

CURLOPT_RTSP_HEADER

This option is simply an alias for CURLOPT_HTTP_HEADER.

Use this to replace the standard headers that RTSP and HTTP share. It is also valid to use the shortcuts such

as CURLOPT_USERAGENT. (Added in 7.20.0)

CURLOPT_RTSP_CLIENT_CSEQ

Manually set the the CSEQ number to issue for the next RTSP request. Useful if the application is resuming a previously broken connection. The CSEQ will increment from this new number henceforth. (Added in 7.20.0)

CURLOPT_RTSP_SERVER_CSEQ

Manually set the CSEQ number to expect for the next

RTSP Server->Client request. At the moment, this

feature (listening for Server requests) is unimple-

mented. (Added in 7.20.0) PROTOCOL OPTIONS

CURLOPT_TRANSFERTEXT

A parameter set to 1 tells the library to use ASCII mode for FTP transfers, instead of the default binary transfer. For win32 systems it does not set the stdout libcurl 7.20.0 Last change: 1 Jan 2010 38

libcurl Manual curl_easy_setopt(3)

to binary mode. This option can be usable when transferring text data between systems with different

views on certain characters, such as newlines or simi-

lar. libcurl does not do a complete ASCII conversion when doing ASCII transfers over FTP. This is a known

limitation/flaw that nobody has rectified. libcurl sim-

ply sets the mode to ASCII and performs a standard transfer.

CURLOPT_PROXY_TRANSFER_MODE

Pass a long. If the value is set to 1 (one), it tells libcurl to set the transfer mode (binary or ASCII) for FTP transfers done via an HTTP proxy, by appending ;type=a or ;type=i to the URL. Without this setting, or it being set to 0 (zero, the default),

CURLOPT_TRANSFERTEXT has no effect when doing FTP via a

proxy. Beware that not all proxies support this feature. (Added in 7.18.0)

CURLOPT_CRLF

Convert Unix newlines to CRLF newlines on transfers.

CURLOPT_RANGE

Pass a char * as parameter, which should contain the specified range you want. It should be in the format

"X-Y", where X or Y may be left out. HTTP transfers

also support several intervals, separated with commas

as in "X-Y,N-M". Using this kind of multiple intervals

will cause the HTTP server to send the response docu-

ment in pieces (using standard MIME separation tech-

niques). For RTSP, the formatting of a range should follow RFC 2326 Section 12.29. For RTSP, byte ranges are not permitted. Instead, ranges should be given in npt, utc, or smpte formats. Pass a NULL to this option to disable the use of ranges. Ranges work on HTTP, FTP, FILE (since 7.18.0), and RTSP (since 7.20.0) transfers only.

CURLOPT_RESUME_FROM

Pass a long as parameter. It contains the offset in number of bytes that you want the transfer to start from. Set this option to 0 to make the transfer start from the beginning (effectively disabling resume). For

FTP, set this option to -1 to make the transfer start

from the end of the target file (useful to continue an interrupted upload). libcurl 7.20.0 Last change: 1 Jan 2010 39

libcurl Manual curl_easy_setopt(3)

CURLOPT_RESUME_FROM_LARGE

Pass a curl_off_t as parameter. It contains the offset

in number of bytes that you want the transfer to start from. (Added in 7.11.0)

CURLOPT_CUSTOMREQUEST

Pass a pointer to a zero terminated string as parame-

ter. It will be used instead of GET or HEAD when doing an HTTP request, or instead of LIST or NLST when doing a FTP directory listing. This is useful for doing DELETE or other more or less obscure HTTP requests. Don't do this at will, make sure your server supports the command first. When you change the request method by setting

CURLOPT_CUSTOMREQUEST to something, you don't actually

change how libcurl behaves or acts in regards to the particular request method, it will only change the actual string sent in the request. For example: if you tell libcurl to do a HEAD request, but then change the request to a "GET" with

CURLOPT_CUSTOMREQUEST you'll still see libcurl act as

if it sent a HEAD even when it does send a GET.

To switch to a proper HEAD, use CURLOPT_NOBODY, to

switch to a proper POST, use CURLOPT_POST or

CURLOPT_POSTFIELDS and so on.

Restore to the internal default by setting this to NULL. Many people have wrongly used this option to replace the entire request with their own, including multiple headers and POST contents. While that might work in many cases, it will cause libcurl to send invalid requests and it could possibly confuse the remote

server badly. Use CURLOPT_POST and CURLOPT_POSTFIELDS

to set POST data. Use CURLOPT_HTTPHEADER to replace or

extend the set of headers sent by libcurl. Use

CURLOPT_HTTP_VERSION to change HTTP version.

CURLOPT_FILETIME

Pass a long. If it is 1, libcurl will attempt to get the modification date of the remote document in this operation. This requires that the remote server sends the time or replies to a time querying command. The

curl_easy_getinfo(3) function with the

CURLINFO_FILETIME argument can be used after a transfer

to extract the received time (if any).

CURLOPT_NOBODY

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libcurl Manual curl_easy_setopt(3)

A parameter set to 1 tells the library to not include

the body-part in the output. This is only relevant for

protocols that have separate header and body parts. On HTTP(S) servers, this will make libcurl do a HEAD request. To change request to GET, you should use

CURLOPT_HTTPGET. Change request to POST with

CURLOPT_POST etc.

CURLOPT_INFILESIZE

When uploading a file to a remote site, this option should be used to tell libcurl what the expected size of the infile is. This value should be passed as a

long. See also CURLOPT_INFILESIZE_LARGE.

For uploading using SCP, this option or

CURLOPT_INFILESIZE_LARGE is mandatory.

This option does not limit how much data libcurl will actually send, as that is controlled entirely by what the read callback returns.

CURLOPT_INFILESIZE_LARGE

When uploading a file to a remote site, this option should be used to tell libcurl what the expected size of the infile is. This value should be passed as a

curl_off_t. (Added in 7.11.0)

For uploading using SCP, this option or

CURLOPT_INFILESIZE is mandatory.

This option does not limit how much data libcurl will actually send, as that is controlled entirely by what the read callback returns.

CURLOPT_UPLOAD

A parameter set to 1 tells the library to prepare for

an upload. The CURLOPT_READDATA and CURLOPT_INFILESIZE

or CURLOPT_INFILESIZE_LARGE options are also interest-

ing for uploads. If the protocol is HTTP, uploading means using the PUT request unless you tell libcurl otherwise. Using PUT with HTTP 1.1 implies the use of a "Expect:

100-continue" header. You can disable this header with

CURLOPT_HTTPHEADER as usual.

If you use PUT to a HTTP 1.1 server, you can upload data without knowing the size before starting the transfer if you use chunked encoding. You enable this

by adding a header like "Transfer-Encoding: chunked"

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libcurl Manual curl_easy_setopt(3)

with CURLOPT_HTTPHEADER. With HTTP 1.0 or without

chunked transfer, you must specify the size.

CURLOPT_MAXFILESIZE

Pass a long as parameter. This allows you to 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 CURLE_FILESIZE_EXCEEDED

will be returned. 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.

CURLOPT_MAXFILESIZE_LARGE

Pass a curl_off_t as parameter. This allows you to

specify the maximum size (in bytes) of a file to down-

load. If the file requested is larger than this value,

the transfer will not start and CURLE_FILESIZE_EXCEEDED

will be returned. (Added in 7.11.0) 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.

CURLOPT_TIMECONDITION

Pass a long as parameter. This defines how the

CURLOPT_TIMEVALUE time value is treated. You can set

this parameter to CURL_TIMECOND_IFMODSINCE or

CURL_TIMECOND_IFUNMODSINCE. This feature applies to

HTTP, FTP, and RTSP. The last modification time of a file is not always known and in such instances this feature will have no effect even if the given time condition would not have

been met. curl_easy_getinfo(3) with the

CURLINFO_CONDITION_UNMET option can be used after a

transfer to learn if a zero-byte successful "transfer"

was due to this condition not matching.

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.

CONNECTION OPTIONS

CURLOPT_TIMEOUT

Pass a long as parameter containing the maximum time in seconds that you allow the libcurl transfer operation to take. Normally, name lookups can take a considerable libcurl 7.20.0 Last change: 1 Jan 2010 42

libcurl Manual curl_easy_setopt(3)

time and limiting operations to less than a few minutes risk aborting perfectly normal operations. This option

will cause curl to use the SIGALRM to enable time-

outing system calls.

In unix-like systems, this might cause signals to be

used unless CURLOPT_NOSIGNAL is set.

CURLOPT_TIMEOUT_MS

Like CURLOPT_TIMEOUT but takes number of milliseconds

instead. If libcurl is built to use the standard system name resolver, that portion of the transfer will still

use full-second resolution for timeouts with a minimum

timeout allowed of one second. (Added in 7.16.2)

CURLOPT_LOW_SPEED_LIMIT

Pass a long as parameter. It contains the transfer speed in bytes per second that the transfer should be

below during CURLOPT_LOW_SPEED_TIME seconds for the

library to consider it too slow and abort.

CURLOPT_LOW_SPEED_TIME

Pass a long as parameter. It contains the time in seconds that the transfer should be below the

CURLOPT_LOW_SPEED_LIMIT for the library to consider it

too slow and abort.

CURLOPT_MAX_SEND_SPEED_LARGE

Pass a curl_off_t as parameter. If an upload exceeds

this speed (counted in bytes per second) on cumulative average during the transfer, the transfer will pause to

keep the average rate less than or equal to the parame-

ter value. Defaults to unlimited speed. (Added in 7.15.5)

CURLOPT_MAX_RECV_SPEED_LARGE

Pass a curl_off_t as parameter. If a download exceeds

this speed (counted in bytes per second) on cumulative average during the transfer, the transfer will pause to

keep the average rate less than or equal to the parame-

ter value. Defaults to unlimited speed. (Added in 7.15.5)

CURLOPT_MAXCONNECTS

Pass a long. The set number will be the persistent con-

nection cache size. The set amount will be the maximum amount of simultaneously open connections that libcurl may cache in this easy handle. Default is 5, and there isn't much point in changing this value unless you are perfectly aware of how this works and changes libcurl's behaviour. This concerns connections using any of the protocols that support persistent connections. libcurl 7.20.0 Last change: 1 Jan 2010 43

libcurl Manual curl_easy_setopt(3)

When reaching the maximum limit, curl closes the oldest one in the cache to prevent increasing the number of open connections. If you already have performed transfers with this curl handle, setting a smaller MAXCONNECTS than before may cause open connections to get closed unnecessarily. If you add this easy handle to a multi handle, this setting is not acknowledged, and you must instead use

curl_multi_setopt(3) and the CURLMOPT_MAXCONNECTS

option.

CURLOPT_CLOSEPOLICY

(Obsolete) This option does nothing.

CURLOPT_FRESH_CONNECT

Pass a long. Set to 1 to make the next transfer use a new (fresh) connection by force. If the connection

cache is full before this connection, one of the exist-

ing connections will be closed as according to the selected or default policy. This option should be used with caution and only if you understand what it does.

Set this to 0 to have libcurl attempt re-using an

existing connection (default behavior).

CURLOPT_FORBID_REUSE

Pass a long. Set to 1 to make the next transfer expli-

citly close the connection when done. Normally, libcurl keeps all connections alive when done with one transfer

in case a succeeding one follows that can re-use them.

This option should be used with caution and only if you understand what it does. Set to 0 to have libcurl keep

the connection open for possible later re-use (default

behavior).

CURLOPT_CONNECTTIMEOUT

Pass a long. It should contain the maximum time in seconds that you allow the connection to the server to take. This only limits the connection phase, once it has connected, this option is of no more use. Set to zero to disable connection timeout (it will then only timeout on the system's internal timeouts). See also

the CURLOPT_TIMEOUT option.

In unix-like systems, this might cause signals to be

used unless CURLOPT_NOSIGNAL is set.

CURLOPT_CONNECTTIMEOUT_MS

Like CURLOPT_CONNECTTIMEOUT but takes the number of

milliseconds instead. If libcurl is built to use the standard system name resolver, that portion of the libcurl 7.20.0 Last change: 1 Jan 2010 44

libcurl Manual curl_easy_setopt(3)

connect will still use full-second resolution for

timeouts with a minimum timeout allowed of one second. (Added in 7.16.2)

CURLOPT_IPRESOLVE

Allows an application to select what kind of IP addresses to use when resolving host names. This is only interesting when using host names that resolve addresses using more than one version of IP. The allowed values are:

CURL_IPRESOLVE_WHATEVER

Default, resolves addresses to all IP versions that your system allows.

CURL_IPRESOLVE_V4

Resolve to IPv4 addresses.

CURL_IPRESOLVE_V6

Resolve to IPv6 addresses.

CURLOPT_CONNECT_ONLY

Pass a long. If the parameter equals 1, it tells the

library to perform all the required proxy authentica-

tion and connection setup, but no data transfer. This option is useful only on HTTP URLs.

This option is useful with the CURLINFO_LASTSOCKET

option to curl_easy_getinfo(3). The library can set up

the connection and then the application can obtain the most recently used socket for special data transfers. (Added in 7.15.2) SSL and SECURITY OPTIONS

CURLOPT_SSLCERT

Pass a pointer to a zero terminated string as parame-

ter. The string should be the file name of your certi-

ficate. The default format is "PEM" and can be changed

with CURLOPT_SSLCERTTYPE.

With NSS this is the nickname of the certificate you wish to authenticate with.

CURLOPT_SSLCERTTYPE

Pass a pointer to a zero terminated string as parame-

ter. The string should be the format of your certifi-

cate. Supported formats are "PEM" and "DER". (Added in 7.9.3)

CURLOPT_SSLKEY

Pass a pointer to a zero terminated string as parame-

ter. The string should be the file name of your private libcurl 7.20.0 Last change: 1 Jan 2010 45

libcurl Manual curl_easy_setopt(3)

key. The default format is "PEM" and can be changed

with CURLOPT_SSLKEYTYPE.

CURLOPT_SSLKEYTYPE

Pass a pointer to a zero terminated string as parame-

ter. The string should be the format of your private key. Supported formats are "PEM", "DER" and "ENG". The format "ENG" enables you to load the private key

from a crypto engine. In this case CURLOPT_SSLKEY is

used as an identifier passed to the engine. You have to

set the crypto engine with CURLOPT_SSLENGINE. "DER"

format key file currently does not work because of a bug in OpenSSL.

CURLOPT_KEYPASSWD

Pass a pointer to a zero terminated string as parame-

ter. It will be used as the password required to use

the CURLOPT_SSLKEY or CURLOPT_SSH_PRIVATE_KEYFILE

private key. You never needed a pass phrase to load a certificate but you need one to load your private key.

(This option was known as CURLOPT_SSLKEYPASSWD up to

7.16.4 and CURLOPT_SSLCERTPASSWD up to 7.9.2)

CURLOPT_SSLENGINE

Pass a pointer to a zero terminated string as parame-

ter. It will be used as the identifier for the crypto engine you want to use for your private key. If the crypto device cannot be loaded,

CURLE_SSL_ENGINE_NOTFOUND is returned.

CURLOPT_SSLENGINE_DEFAULT

Sets the actual crypto engine as the default for (asym-

metric) crypto operations. If the crypto device cannot be set,

CURLE_SSL_ENGINE_SETFAILED is returned.

Even though this option doesn't need any parameter, in

some configurations curl_easy_setopt might be defined

as a macro taking exactly three arguments. Therefore, it's recommended to pass 1 as parameter to this option.

CURLOPT_SSLVERSION

Pass a long as parameter to control what version of

SSL/TLS to attempt to use. The available options are:

CURL_SSLVERSION_DEFAULT

The default action. This will attempt to figure out the remote SSL protocol version, i.e. either libcurl 7.20.0 Last change: 1 Jan 2010 46

libcurl Manual curl_easy_setopt(3)

SSLv3 or TLSv1 (but not SSLv2, which became dis-

abled by default with 7.18.1).

CURL_SSLVERSION_TLSv1

Force TLSv1

CURL_SSLVERSION_SSLv2

Force SSLv2

CURL_SSLVERSION_SSLv3

Force SSLv3

CURLOPT_SSL_VERIFYPEER

Pass a long as parameter. This option determines whether curl verifies the authenticity of the peer's certificate. A value of 1 means curl verifies; zero means it doesn't. The default is nonzero, but before 7.10, it was zero. When negotiating an SSL connection, the server sends a certificate indicating its identity. Curl verifies whether the certificate is authentic, i.e. that you can trust that the server is who the certificate says it

is. This trust is based on a chain of digital signa-

tures, rooted in certification authority (CA) certifi-

cates you supply. As of 7.10, curl installs a default bundle of CA certificates and you can specify alternate

certificates with the CURLOPT_CAINFO option or the

CURLOPT_CAPATH option.

When CURLOPT_SSL_VERIFYPEER is nonzero, and the verifi-

cation fails to prove that the certificate is authen-

tic, the connection fails. When the option is zero, the connection succeeds regardless. Authenticating the certificate is not by itself very useful. You typically want to ensure that the server, as authentically identified by its certificate, is the server you mean to be talking to. Use

CURLOPT_SSL_VERIFYHOST to control that.

CURLOPT_CAINFO

Pass a char * to a zero terminated string naming a file holding one or more certificates to verify the peer with. This makes sense only when used in combination

with the CURLOPT_SSL_VERIFYPEER option. If

CURLOPT_SSL_VERIFYPEER is zero, CURLOPT_CAINFO need not

even indicate an accessible file. This option is by default set to the system path where libcurl's cacert bundle is assumed to be stored, as libcurl 7.20.0 Last change: 1 Jan 2010 47

libcurl Manual curl_easy_setopt(3)

established at build time. When built against NSS, this is the directory that the NSS certificate database resides in.

CURLOPT_ISSUERCERT

Pass a char * to a zero terminated string naming a file holding a CA certificate in PEM format. If the option

is set, an additional check against the peer certifi-

cate is performed to verify the issuer is indeed the one associated with the certificate provided by the

option. This additional check is useful in multi-level

PKI where one needs to enforce that the peer certifi-

cate is from a specific branch of the tree. This option makes sense only when used in combination

with the CURLOPT_SSL_VERIFYPEER option. Otherwise, the

result of the check is not considered as failure.

A specific error code (CURLE_SSL_ISSUER_ERROR) is

defined with the option, which is returned if the setup

of the SSL/TLS session has failed due to a mismatch with the issuer of peer certificate

(CURLOPT_SSL_VERIFYPEER has to be set too for the check

to fail). (Added in 7.19.0)

CURLOPT_CAPATH

Pass a char * to a zero terminated string naming a directory holding multiple CA certificates to verify the peer with. The certificate directory must be

prepared using the openssl c_rehash utility. This makes

sense only when used in combination with the

CURLOPT_SSL_VERIFYPEER option. If

CURLOPT_SSL_VERIFYPEER is zero, CURLOPT_CAPATH need not

even indicate an accessible path. The CURLOPT_CAPATH

function apparently does not work in Windows due to

some limitation in openssl. This option is OpenSSL-

specific and does nothing if libcurl is built to use GnuTLS.

CURLOPT_CRLFILE

Pass a char * to a zero terminated string naming a file with the concatenation of CRL (in PEM format) to use in the certificate validation that occurs during the SSL exchange. When curl is built to use NSS or GnuTLS, there is no way to influence the use of CRL passed to help in the verification process. When libcurl is built with

OpenSSL support, X509_V_FLAG_CRL_CHECK and

X509_V_FLAG_CRL_CHECK_ALL are both set, requiring CRL

check against all the elements of the certificate chain libcurl 7.20.0 Last change: 1 Jan 2010 48

libcurl Manual curl_easy_setopt(3)

if a CRL file is passed. This option makes sense only when used in combination

with the CURLOPT_SSL_VERIFYPEER option.

A specific error code (CURLE_SSL_CRL_BADFILE) is

defined with the option. It is returned when the SSL exchange fails because the CRL file cannot be loaded.

A failure in certificate verification due to a revoca-

tion information found in the CRL does not trigger this specific error. (Added in 7.19.0)

CURLOPT_CERTINFO

Pass a long set to 1 to enable libcurl's certificate chain info gatherer. With this enabled, libcurl (if built with OpenSSL) will extract lots of information and data about the certificates in the certificate chain used in the SSL connection. This data is then possible to extract after a transfer using

curl_easy_getinfo(3) and its option CURLINFO_CERTINFO.

(Added in 7.19.1)

CURLOPT_RANDOM_FILE

Pass a char * to a zero terminated file name. The file will be used to read from to seed the random engine for SSL. The more random the specified file is, the more secure the SSL connection will become.

CURLOPT_EGDSOCKET

Pass a char * to the zero terminated path name to the Entropy Gathering Daemon socket. It will be used to seed the random engine for SSL.

CURLOPT_SSL_VERIFYHOST

Pass a long as parameter. This option determines whether libcurl verifies that the server cert is for the server it is known as. When negotiating a SSL connection, the server sends a certificate indicating its identity.

When CURLOPT_SSL_VERIFYHOST is 2, that certificate must

indicate that the server is the server to which you meant to connect, or the connection fails. Curl considers the server the intended one when the Common Name field or a Subject Alternate Name field in the certificate matches the host name in the URL to which you told Curl to connect. When the value is 1, the certificate must contain a libcurl 7.20.0 Last change: 1 Jan 2010 49

libcurl Manual curl_easy_setopt(3)

Common Name field, but it doesn't matter what name it says. (This is not ordinarily a useful setting). When the value is 0, the connection succeeds regardless of the names in the certificate. The default, since 7.10, is 2. This option controls checking the server's claimed identity. The server could be lying. To control

lying, see CURLOPT_SSL_VERIFYPEER.

CURLOPT_SSL_CIPHER_LIST

Pass a char *, pointing to a zero terminated string

holding the list of ciphers to use for the SSL connec-

tion. The list must be syntactically correct, it con-

sists of one or more cipher strings separated by colons. Commas or spaces are also acceptable separators

but colons are normally used, !, - and + can be used as

operators. For OpenSSL and GnuTLS valid examples of cipher lists

include 'RC4-SHA', 'SHA1+DES', 'TLSv1' and 'DEFAULT'.

The default list is normally set when you compile OpenSSL. You'll find more details about cipher lists on this URL: http://www.openssl.org/docs/apps/ciphers.html For NSS, valid examples of cipher lists include

'rsa_rc4_128_md5', 'rsa_aes_128_sha', etc. With NSS you

don't add/remove ciphers. If one uses this option then all known ciphers are disabled and only those passed in are enabled. You'll find more details about the NSS cipher lists on this URL:

http://directory.fedora.redhat.com/docs/mod_nss.html#Directives

CURLOPT_SSL_SESSIONID_CACHE

Pass a long set to 0 to disable libcurl's use of SSL

session-ID caching. Set this to 1 to enable it. By

default all transfers are done using the cache. While nothing ever should get hurt by attempting to reuse SSL

session-IDs, there seem to be broken SSL implementa-

tions in the wild that may require you to disable this in order for you to succeed. (Added in 7.16.0)

CURLOPT_KRBLEVEL

Pass a char * as parameter. Set the kerberos security level for FTP; this also enables kerberos awareness. libcurl 7.20.0 Last change: 1 Jan 2010 50

libcurl Manual curl_easy_setopt(3)

This is a string, 'clear', 'safe', 'confidential' or 'private'. If the string is set but doesn't match one of these, 'private' will be used. Set the string to NULL to disable kerberos support for FTP.

(This option was known as CURLOPT_KRB4LEVEL up to

7.16.3) SSH OPTIONS

CURLOPT_SSH_AUTH_TYPES

Pass a long set to a bitmask consisting of one or more

of CURLSSH_AUTH_PUBLICKEY, CURLSSH_AUTH_PASSWORD,

CURLSSH_AUTH_HOST, CURLSSH_AUTH_KEYBOARD. Set

CURLSSH_AUTH_ANY to let libcurl pick one. (Added in

7.16.1)

CURLOPT_SSH_HOST_PUBLIC_KEY_MD5

Pass a char * pointing to a string containing 32 hexa-

decimal digits. The string should be the 128 bit MD5 checksum of the remote host's public key, and libcurl will reject the connection to the host unless the md5sums match. This option is only for SCP and SFTP transfers. (Added in 7.17.1)

CURLOPT_SSH_PUBLIC_KEYFILE

Pass a char * pointing to a file name for your public key. If not used, libcurl defaults to using

~/.ssh/id_dsa.pub. (Added in 7.16.1)

CURLOPT_SSH_PRIVATE_KEYFILE

Pass a char * pointing to a file name for your private key. If not used, libcurl defaults to using

~/.ssh/id_dsa. If the file is password-protected, set

the password with CURLOPT_KEYPASSWD. (Added in 7.16.1)

CURLOPT_SSH_KNOWNHOSTS

Pass a pointer to a zero terminated string holding the

file name of the known_host file to use. The

known_hosts file should use the OpenSSH file format as

supported by libssh2. If this file is specified, lib-

curl will only accept connections with hosts that are known and present in that file, with a matching public

key. Use CURLOPT_SSH_KEYFUNCTION to alter the default

behavior on host and key (mis)matching. (Added in 7.19.6)

CURLOPT_SSH_KEYFUNCTION

Pass a pointer to a curl_sshkeycallback function. It

gets called when the known_host matching has been done,

to allow the application to act and decide for libcurl how to proceed. It gets passed the CURL handle, the key

from the known_hosts file, the key from the remote

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libcurl Manual curl_easy_setopt(3)

site, info from libcurl on the matching status and a

custom pointer (set with CURLOPT_SSH_KEYDATA). It MUST

return one of the following return codes to tell lib-

curl how to act:

CURLKHSTAT_FINE_ADD_TO_FILE

The host+key is accepted and libcurl will append

it to the known_hosts file before continuing with

the connection. This will also add the host+key

combo to the known_host pool kept in memory if it

wasn't already present there. The adding of data to the file is done by completely replacing the file with a new copy, so the permissions of the file must allow this.

CURLKHSTAT_FINE

The host+key is accepted libcurl will continue with the connection. This will also add the

host+key combo to the known_host pool kept in

memory if it wasn't already present there.

CURLKHSTAT_REJECT

The host+key is rejected. libcurl will deny the connection to continue and it will be closed.

CURLKHSTAT_DEFER

The host+key is rejected, but the SSH connection is asked to be kept alive. This feature could be used when the app wants to somehow return back and act on the host+key situation and then retry without needing the overhead of setting it up from scratch again. (Added in 7.19.6)

CURLOPT_SSH_KEYDATA

Pass a void * as parameter. This pointer will be passed along verbatim to the callback set with

CURLOPT_SSH_KEYFUNCTION. (Added in 7.19.6)

OTHER OPTIONS

CURLOPT_PRIVATE

Pass a void * as parameter, pointing to data that should be associated with this curl handle. The pointer can subsequently be retrieved using

curl_easy_getinfo(3) with the CURLINFO_PRIVATE option.

libcurl itself does nothing with this data. (Added in 7.10.3)

CURLOPT_SHARE

Pass a share handle as a parameter. The share handle must have been created by a previous call to

curl_share_init(3). Setting this option, will make this

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libcurl Manual curl_easy_setopt(3)

curl handle use the data from the shared handle instead of keeping the data to itself. This enables several curl handles to share data. If the curl handles are used simultaneously in multiple threads, you MUST use the locking methods in the share handle. See

curl_share_setopt(3) for details.

If you add a share that is set to share cookies, your easy handle will use that cookie cache and get the cookie engine enabled. If you unshare an object that was using cookies (or change to another object that doesn't share cookies), the easy handle will get its cookie engine disabled. Data that the share object is not set to share will be dealt with the usual way, as if no share was used.

CURLOPT_NEW_FILE_PERMS

Pass a long as a parameter, containing the value of the permissions that will be assigned to newly created files on the remote server. The default value is 0644, but any valid value can be used. The only protocols that can use this are sftp://, scp://, and file://. (Added in 7.16.4)

CURLOPT_NEW_DIRECTORY_PERMS

Pass a long as a parameter, containing the value of the permissions that will be assigned to newly created directories on the remote server. The default value is

0755, but any valid value can be used. The only proto-

cols that can use this are sftp://, scp://, and file://. (Added in 7.16.4) TELNET OPTIONS

CURLOPT_TELNETOPTIONS

Provide a pointer to a curl_slist with variables to

pass to the telnet negotiations. The variables should be in the format . libcurl supports the

options 'TTYPE', 'XDISPLOC' and 'NEW_ENV'. See the TEL-

NET standard for details. RETURN VALUE

CURLE_OK (zero) means that the option was set properly,

non-zero means an error occurred as defines.

See the libcurl-errors(3) man page for the full list with

descriptions. If you try to set an option that libcurl doesn't know about, perhaps because the library is too old to support it or the option was removed in a recent version, this function will

return CURLE_FAILED_INIT.

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ATTRIBUTES

See attributes(5) for descriptions of the following attri-

butes:

_______________________________________

| ATTRIBUTE TYPE | ATTRIBUTE VALUE|

|____________________|__________________|_

| Availability | web/curl |

|____________________|__________________|_

| Interface Stability| Uncommitted |

|____________________|_________________|

NOTES

Source for C-URL is available on http://opensolaris.org.

libcurl 7.20.0 Last change: 1 Jan 2010 54