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curl_easy_setopt

NAME

SYNOPSIS

CURLcode curl_easy_setopt(CURL *handle, CURLoption option, parameter);  

DESCRIPTION

NOTE: strings passed to libcurl as 'char *' arguments, will not be copied by the library. Instead you should keep them available until libcurl no longer needs them. Failing to do so will cause very odd behavior or even crashes.

NOTE2: options set with this function call are valid for the forthcoming data transfers that are performed when you invoke curl_easy_perform. 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.

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

OPTIONS

CURLOPT_FILE

Data pointer to pass to the file write function. Note that if you specify the CURLOPT_WRITEFUNCTION, this is the pointer you'll get as input. If you don't use a callback, you must pass a 'FILE *' as libcurl will pass this to fwrite() when writing data.

NOTE: 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.

CURLOPT_WRITEFUNCTION

Function pointer that should match the following prototype: size_t function( void *ptr, size_t size, size_t nmemb, void *stream); This function gets called by libcurl as soon as there is data available to pass available that needs to be saved. The size of the data pointed to by ptr is size multiplied with nmemb. 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 and it will abort the transfer and return CURLE_WRITE_ERROR.

Set the stream argument with the CURLOPT_FILE option.

NOTE: you 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.

CURLOPT_INFILE

Data pointer to pass to the file read function. Note that if you specify the CURLOPT_READFUNCTION, this is the pointer you'll get as input. If you don't specify a read callback, this must be a valid FILE *.

NOTE: If you're using libcurl as a win32 DLL, you MUST use a CURLOPT_READFUNCTION if you set this option.

CURLOPT_READFUNCTION

Function pointer that should match the following prototype: size_t function( void *ptr, size_t size, size_t nmemb, void *stream); 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.

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.

CURLOPT_URL

The actual URL to deal with. The parameter should be a char * to a zero terminated string. The string must remain present until curl no longer needs it, as it doesn't copy the string.

NOTE: this option is (the only one) required to be set before curl_easy_perform(3) is called.

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 CURLOPT_PROXYPORT.

NOTE: when you tell the library to use a HTTP proxy, libcurl will transparently convert operations to HTTP even if you specify a 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 tunneling is activated with CURLOPT_HTTPPROXYTUNNEL.

NOTE2: libcurl respects the environment variables http_proxy, ftp_proxy, all_proxy etc, if any of those is set.

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_HTTPPROXYTUNNEL

Set the parameter to non-zero to get the library to tunnel all operations through a given HTTP proxy. Note that 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. (Added in libcurl 7.3)

CURLOPT_VERBOSE

Set the parameter to non-zero to get the library to display a lot of verbose information about its operations. Very useful for libcurl and/or protocol debugging and understanding.

You hardly ever want this set in production use, you will almost always want this when you debug/report problems.

CURLOPT_HEADER

A non-zero parameter 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 non-zero parameter tells the library to shut of the built-in progress meter completely.

NOTE: future versions of libcurl is likely to not have any built-in progress meter at all.

CURLOPT_NOBODY

A non-zero parameter 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.

CURLOPT_FAILONERROR

A non-zero parameter tells the library to fail silently if the HTTP code returned is equal to or larger than 300. The default action would be to return the page normally, ignoring that code.

CURLOPT_UPLOAD

A non-zero parameter tells the library to prepare for an upload. The CURLOPT_INFILE and CURLOPT_INFILESIZE are also interesting for uploads.

CURLOPT_POST

A non-zero parameter tells the library to do a regular HTTP post. This is a normal application/x-www-form-urlencoded kind, which is the most commonly used one by HTML forms. See the CURLOPT_POSTFIELDS option for how to specify the data to post and CURLOPT_POSTFIELDSIZE in how to set the data size. Starting with libcurl 7.8, this option is obsolete. Using the CURLOPT_POSTFIELDS option will imply this option.

CURLOPT_FTPLISTONLY

A non-zero parameter tells the library to just list the names of an ftp directory, instead of doing a full directory listing that would include file sizes, dates etc.

CURLOPT_FTPAPPEND

A non-zero parameter tells the library to append to the remote file instead of overwrite it. This is only useful when uploading to a ftp site.

CURLOPT_NETRC

A non-zero parameter tells the library to scan your ~/.netrc file to find user name and password for the remote site you are about to access. Only machine name, user name and password is taken into account (init macros and similar things aren't supported).

Note: libcurl does not verify that the file has the correct properties set (as the standard Unix ftp client does). It should only be readable by user.

CURLOPT_FOLLOWLOCATION

A non-zero parameter tells the library to follow any Location: header that the server sends as part of a HTTP header.

NOTE: this means that the library will re-send the same request on the new location and follow new Location: headers all the way until no more such headers are returned. CURLOPT_MAXREDIRS can be used to limit the number of redirects libcurl will follow.

CURLOPT_TRANSFERTEXT

A non-zero parameter tells the library to use ASCII mode for ftp transfers, instead of the default binary transfer. For LDAP transfers it gets the data in plain text instead of HTML and for win32 systems it does not set the stdout to binary mode. This option can be usable when transferring text data between systems with different views on certain characters, such as newlines or similar.

CURLOPT_PUT

A non-zero parameter tells the library to use HTTP PUT to transfer data. The data should be set with CURLOPT_INFILE and CURLOPT_INFILESIZE.

CURLOPT_USERPWD

Pass a char * as parameter, which should be [user name]:[password] to use for the connection. If the password is left out, you will be prompted for it. CURLOPT_PASSWDFUNCTION can be used to set your own prompt function.

CURLOPT_PROXYUSERPWD

Pass a char * as parameter, which should be [user name]:[password] to use for the connection to the HTTP proxy. If the password is left out, you will be prompted for it. CURLOPT_PASSWDFUNCTION can be used to set your own prompt function.

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 document in pieces (using standard MIME separation techniques).

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 the library. The buffer must be at least CURL_ERROR_SIZE big.

Note: 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_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 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.

NOTE: this does not work in Unix multi-threaded programs, as it uses signals.

CURLOPT_POSTFIELDS

Pass a char * as parameter, which should be the full data to post in a HTTP post operation. This is a normal application/x-www-form-urlencoded kind, which is the most commonly used one by HTML forms. See also the CURLOPT_POST. Since 7.8, using CURLOPT_POSTFIELDS implies CURLOPT_POST.

Note: to make multipart/formdata posts (aka rfc1867-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 zero, the library will use strlen() to get the size. (Added in libcurl 7.2)

CURLOPT_REFERER

Pass a pointer to a zero terminated string as parameter. It will be used to set the Referer: header in the http request sent to the remote server. This can be used to fool servers or scripts. You can also set any custom header with CURLOPT_HTTPHEADER.

CURLOPT_USERAGENT

Pass a pointer to a zero terminated string as parameter. It will be used to set the User-Agent: header in the http request sent to the remote server. This can be used to fool servers or scripts. You can also set any custom header with CURLOPT_HTTPHEADER.

CURLOPT_FTPPORT

Pass a pointer to a zero terminated string as parameter. It will be used to get the IP address to use for the ftp PORT instruction. The PORT instruction tells the remote server to connect to our specified IP address. The string may be a plain IP address, a host name, an network interface name (under Unix) or just a '-' letter to let the library use your systems default IP address. Default FTP operations are passive, and thus won't use PORT.

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_RESUME_FROM

Pass a long as parameter. It contains the offset in number of bytes that you want the transfer to start from.

CURLOPT_COOKIE

Pass a pointer to a zero terminated string as parameter. It will be used to set a cookie in the http request. The format of the string should be [NAME]=[CONTENTS]; Where NAME is the cookie name.

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 contents as in 'Accept:' (no data on the right side of the colon), the internally used header will get disabled. Thus, using this option you can add new headers, replace internal headers and remove internal headers.

NOTE:The most commonly replaced headers have "shortcuts" in the options CURLOPT_COOKIE, CURLOPT_USERAGENT and CURLOPT_REFERER.

CURLOPT_HTTPPOST

Tells libcurl you want a multipart/formdata HTTP POST to be made and you instruct what data to pass on to the server. Pass a pointer to a linked list of HTTP post structs as parameter. The linked list should be a fully valid list of 'struct HttpPost' structs properly filled in. The best and most elegant way to do this, is to use curl_formadd(3) as documented. The data in this list must remained intact until you close this curl handle again with curl_easy_cleanup(3).

CURLOPT_SSLCERT

Pass a pointer to a zero terminated string as parameter. The string should be the file name of your certificate. The default format is "PEM" and can be changed with CURLOPT_SSLCERTTYPE.

CURLOPT_SSLCERTTYPE

Pass a pointer to a zero terminated string as parameter. The string should be the format of your certificate. Supported formats are "PEM" and "DER". (Added in 7.9.3)

CURLOPT_SSLCERTPASSWD

Pass a pointer to a zero terminated string as parameter. It will be used as the password required to use the CURLOPT_SSLCERT certificate. If the password is not supplied, you will be prompted for it. CURLOPT_PASSWDFUNCTION can be used to set your own prompt function.

NOTE:This option is replaced by CURLOPT_SSLKEYPASSWD and only cept for backward compatibility. You never needed a pass phrase to load a certificate but you need one to load your private key.

CURLOPT_SSLKEY

Pass a pointer to a zero terminated string as parameter. The string should be the file name of your private key. The default format is "PEM" and can be changed with CURLOPT_SSLKEYTYPE. (Added in 7.9.3)

CURLOPT_SSLKEYTYPE

Pass a pointer to a zero terminated string as parameter. The string should be the format of your private key. Supported formats are "PEM", "DER" and "ENG". (Added in 7.9.3)

NOTE: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_SSL_ENGINE.

CURLOPT_SSLKEYASSWD

Pass a pointer to a zero terminated string as parameter. It will be used as the password required to use the CURLOPT_SSLKEY private key. If the password is not supplied, you will be prompted for it. CURLOPT_PASSWDFUNCTION can be used to set your own prompt function. (Added in 7.9.3)

CURLOPT_SSL_ENGINE

Pass a pointer to a zero terminated string as parameter. It will be used as the identifier for the crypto engine you want to use for your private key. (Added in 7.9.3)

NOTE:If the crypto device cannot be loaded, CURLE_SSL_ENGINE_NOTFOUND is returned.

CURLOPT_SSL_ENGINEDEFAULT

Sets the actual crypto engine as the default for (asymetric) crypto operations. (Added in 7.9.3)

NOTE:If the crypto device cannot be set, CURLE_SSL_ENGINE_SETFAILED is returned.

CURLOPT_CRLF

Convert Unix newlines to CRLF newlines on FTP uploads.

CURLOPT_QUOTE

Pass a pointer to a linked list of FTP commands to pass to the server prior to your ftp request. The linked list should be a fully valid list of 'struct curl_slist' structs properly filled in. 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.

CURLOPT_POSTQUOTE

Pass a pointer to a linked list of FTP commands to pass to the server after your ftp transfer request. The linked list should be a fully valid list of struct curl_slist structs properly filled in as described for CURLOPT_QUOTE. Disable this operation again by setting a NULL to this option.

CURLOPT_WRITEHEADER

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 below on how to set a custom get-all-headers callback.

CURLOPT_HEADERFUNCTION

Function pointer that should match the following prototype: size_t function( void *ptr, size_t size, size_t nmemb, void *stream);. This function gets called by libcurl as soon as there is received header data that needs to be written down. The headers are guaranteed to be written one-by-one and only complete lines are written. Parsing headers should be easy enough using this. The size of the data pointed to by ptr is size multiplied with nmemb. The pointer named stream will be the one you passed to libcurl with the CURLOPT_WRITEHEADER option. Return the number of bytes actually written or return -1 to signal error to the library (it will cause it to abort the transfer with a CURLE_WRITE_ERROR return code). (Added in libcurl 7.7.2)

CURLOPT_COOKIEFILE

Pass a pointer to a zero terminated string as parameter. It should contain the name of your file holding cookie data. The cookie data may be in Netscape / Mozilla cookie data format or just regular HTTP-style headers dumped to a file.

CURLOPT_SSLVERSION

Pass a long as parameter. Set what version of SSL to attempt to use, 2 or 3. By default, the SSL library will try to solve this by itself although some servers make this difficult why you at times may have to use this option.

CURLOPT_TIMECONDITION

Pass a long as parameter. This defines how the CURLOPT_TIMEVALUE time value is treated. You can set this parameter to TIMECOND_IFMODSINCE or TIMECOND_IFUNMODSINCE. This is a HTTP-only feature. (TBD)

CURLOPT_TIMEVALUE

Pass a long as parameter. This should be the time in seconds since 1 jan 1970, and the time will be used as specified in CURLOPT_TIMECONDITION or if that isn't used, it will be TIMECOND_IFMODSINCE by default.

CURLOPT_CUSTOMREQUEST

Pass a pointer to a zero terminated string as parameter. It will be user instead of GET or HEAD when doing the HTTP request. 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.

CURLOPT_STDERR

Pass a FILE * as parameter. This is the stream to use instead of stderr internally when reporting errors.

CURLOPT_INTERFACE

Pass a char * as parameter. This set the interface name to use as outgoing network interface. The name can be an interface name, an IP address or a host name. (Added in libcurl 7.3)

CURLOPT_KRB4LEVEL

Pass a char * as parameter. Set the krb4 security level, this also enables krb4 awareness. 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 kerberos4. The kerberos support only works for FTP. (Added in libcurl 7.3)

CURLOPT_PROGRESSFUNCTION

Function pointer that should match the curl_progress_callback prototype found in <curl/curl.h>. This function gets called by libcurl instead of its internal equivalent with a frequent interval during data transfer. Unknown/unused argument values 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.

CURLOPT_PROGRESSDATA

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

CURLOPT_SSL_VERIFYPEER

Pass a long that is set to a non-zero value to make curl verify the peer's certificate. The certificate to verify against must be specified with the CURLOPT_CAINFO option. (Added in 7.4.2)

CURLOPT_CAINFO

Pass a char * to a zero terminated file naming holding the certificate to verify the peer with. This only makes sense when used in combination with the CURLOPT_SSL_VERIFYPEER option. (Added in 7.4.2)

CURLOPT_PASSWDFUNCTION

Pass a pointer to a curl_passwd_callback function that will be called instead of the internal one if libcurl requests a password. The function must match this prototype: int my_getpass(void *client, char *prompt, char* buffer, int buflen );. If set to NULL, it equals to making the function always fail. If the function returns a non-zero value, it will abort the operation and an error (CURLE_BAD_PASSWORD_ENTERED) will be returned. client is a generic pointer, see CURLOPT_PASSWDDATA. prompt is a zero-terminated string that is text that prefixes the input request. buffer is a pointer to data where the entered password should be stored and buflen is the maximum number of bytes that may be written in the buffer. (Added in 7.4.2)

CURLOPT_PASSWDDATA

Pass a void * to whatever data you want. The passed pointer will be the first argument sent to the specifed CURLOPT_PASSWDFUNCTION function. (Added in 7.4.2)

CURLOPT_FILETIME

Pass a long. If it is a non-zero value, 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). (Added in 7.5)

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 7.5)

CURLOPT_MAXCONNECTS

Pass a long. The set number will be the persistant connection cache size. The set amount will be the maximum amount of simultaneous connections that libcurl may cache between file transfers. Default is 5, and there isn't much point in changing this value unless you are perfectly aware of how this work and changes libcurl's behaviour.

NOTE: if you already have performed transfers with this curl handle, setting a smaller MAXCONNECTS than before may cause open connections to get closed unnecessarily. (Added in 7.7)

CURLOPT_CLOSEPOLICY

Pass a long. This option sets what policy libcurl should use when the connection cache is filled and one of the open connections has to be closed to make room for a new connection. This must be one of the CURLCLOSEPOLICY_* defines. Use CURLCLOSEPOLICY_LEAST_RECENTLY_USED to make libcurl close the connection that was least recently used, that connection is also least likely to be capable of re-use. Use CURLCLOSEPOLICY_OLDEST to make libcurl close the oldest connection, the one that was created first among the ones in the connection cache. The other close policies are not support yet. (Added in 7.7)

CURLOPT_FRESH_CONNECT

Pass a long. Set to non-zero to make the next transfer use a new (fresh) connection by force. If the connection cache is full before this connection, one of the existing 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). (Added in 7.7)

CURLOPT_FORBID_REUSE

Pass a long. Set to non-zero to make the next transfer explicitly close the connection when done. Normally, libcurl keep all connections alive when done with one transfer in case there comes a succeeding one 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 possibly later re-use (default behavior). (Added in 7.7)

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 will the SSL connection 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_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.

NOTE: this does not work in unix multi-threaded programs, as it uses signals.

CURLOPT_HTTPGET

Pass a long. If the long is non-zero, this forces the HTTP request to get back to GET. Only really usable if POST, PUT or a custom request have been used previously using the same curl handle. (Added in 7.8.1)

CURLOPT_SSL_VERIFYHOST

Pass a long. Set if we should verify the Common name from the peer certificate in the SSL handshake, set 1 to check existence, 2 to ensure that it matches the provided hostname. (Added in 7.8.1)

CURLOPT_COOKIEJAR

Pass a file name as char *, zero terminated. This will make libcurl dump 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.

CURLOPT_SSL_CIPHER_LIST

Pass a char *, pointing to a zero terminated string holding the list of ciphers to use for the SSL connection. The list must be syntactly correct, it consists 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. 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

CURLOPT_HTTP_VERSION

Pass a long, set to one of the values described below. They force libcurl to use the specific HTTP versions. This is not sensible to do unless you have a good reason.

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_FTP_USE_EPSV

Pass a long. If the value is non-zero, it tells curl to use the EPSV command when doing passive FTP downloads (which is always does by default). Using EPSV means that it will first attempt to use EPSV before using PASV, but if you pass FALSE (zero) to this option, it will not try using EPSV, only plain PASV.

RETURN VALUE

SEE ALSO

BUGS

Index

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

RETURN VALUE

SEE ALSO

BUGS