diff options
Diffstat (limited to 'plugins/FTPFileYM/curl-7.29.0/docs/libcurl/curl_easy_setopt.3')
| -rw-r--r-- | plugins/FTPFileYM/curl-7.29.0/docs/libcurl/curl_easy_setopt.3 | 2527 |
1 files changed, 2527 insertions, 0 deletions
diff --git a/plugins/FTPFileYM/curl-7.29.0/docs/libcurl/curl_easy_setopt.3 b/plugins/FTPFileYM/curl-7.29.0/docs/libcurl/curl_easy_setopt.3 new file mode 100644 index 0000000000..3d31aef7cf --- /dev/null +++ b/plugins/FTPFileYM/curl-7.29.0/docs/libcurl/curl_easy_setopt.3 @@ -0,0 +1,2527 @@ +.\" ************************************************************************** +.\" * _ _ ____ _ +.\" * Project ___| | | | _ \| | +.\" * / __| | | | |_) | | +.\" * | (__| |_| | _ <| |___ +.\" * \___|\___/|_| \_\_____| +.\" * +.\" * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al. +.\" * +.\" * This software is licensed as described in the file COPYING, which +.\" * you should have received as part of this distribution. The terms +.\" * are also available at http://curl.haxx.se/docs/copyright.html. +.\" * +.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell +.\" * copies of the Software, and permit persons to whom the Software is +.\" * furnished to do so, under the terms of the COPYING file. +.\" * +.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY +.\" * KIND, either express or implied. +.\" * +.\" ************************************************************************** +.\" +.TH curl_easy_setopt 3 "1 Jan 2010" "libcurl 7.20.0" "libcurl Manual" +.SH NAME +curl_easy_setopt \- set options for a curl easy handle +.SH SYNOPSIS +#include <curl/curl.h> + +CURLcode curl_easy_setopt(CURL *handle, CURLoption option, parameter); +.SH DESCRIPTION +curl_easy_setopt() is used to tell libcurl how to behave. By using the +appropriate options to \fIcurl_easy_setopt\fP, you can change libcurl's +behavior. All options are set with the \fIoption\fP followed by a +\fIparameter\fP. That parameter can be a \fBlong\fP, a \fBfunction pointer\fP, +an \fBobject pointer\fP or a \fBcurl_off_t\fP, 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 forthcoming transfers +performed using this \fIhandle\fP. 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 \fIcurl_easy_reset(3)\fP. + +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 \fIhandle\fP is the return code from a \fIcurl_easy_init(3)\fP or +\fIcurl_easy_duphandle(3)\fP call. +.SH BEHAVIOR OPTIONS +.IP 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 understanding. The verbose information will be sent to stderr, +or the stream set with \fICURLOPT_STDERR\fP. + +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 +\fICURLOPT_DEBUGFUNCTION\fP. +.IP 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). +.IP CURLOPT_NOPROGRESS +Pass a long. If set to 1, it tells the library to shut off the progress meter +completely. It will also prevent the \fICURLOPT_PROGRESSFUNCTION\fP from +getting called. + +Future versions of libcurl are likely to not have any built-in progress meter +at all. +.IP CURLOPT_NOSIGNAL +Pass a long. If it is 1, libcurl will not use any functions 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. + +Setting \fICURLOPT_NOSIGNAL\fP to 1 makes libcurl NOT ask the system to ignore +SIGPIPE signals, which otherwise are sent by the system when trying to send +data to a socket which is closed in the other end. libcurl makes an effort to +never cause such SIGPIPEs to trigger, but some operating systems have no way +to avoid them and even on those that have there are some corner cases when +they may still happen, contrary to our desire. In addition, using +\fICURLAUTH_NTLM_WB\fP authentication could cause a SIGCHLD signal to be +raised. +.IP 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 +\fICURLOPT_URL\fP 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 function by the \fICURLOPT_FNMATCH_FUNCTION\fP +option. + +This feature is only supported by the FTP download for now. + +A brief introduction of its syntax follows: +.RS +.IP "* - ASTERISK" +\&ftp://example.com/some/path/\fB*.txt\fP (for all txt's from the root +directory) +.RE +.RS +.IP "? - QUESTION MARK" +Question mark matches any (exactly one) character. + +\&ftp://example.com/some/path/\fBphoto?.jpeg\fP +.RE +.RS +.IP "[ - 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: + +\fB[a-zA-Z0\-9]\fP or \fB[f\-gF\-G]\fP \- character interval + +\fB[abc]\fP - character enumeration + +\fB[^abc]\fP or \fB[!abc]\fP - negation + +\fB[[:\fP\fIname\fP\fB:]]\fP class expression. Supported classes are +\fBalnum\fP,\fBlower\fP, \fBspace\fP, \fBalpha\fP, \fBdigit\fP, \fBprint\fP, +\fBupper\fP, \fBblank\fP, \fBgraph\fP, \fBxdigit\fP. + +\fB[][-!^]\fP - special case \- matches only '\-', ']', '[', '!' or '^'. These +characters have no special purpose. + +\fB[\\[\\]\\\\]\fP - escape syntax. Matches '[', ']' or '\\'. + +Using the rules above, a file name pattern can be constructed: + +\&ftp://example.com/some/path/\fB[a-z[:upper:]\\\\].jpeg\fP +.RE +.PP +(This was added in 7.21.0) +.SH CALLBACK OPTIONS +.IP CURLOPT_WRITEFUNCTION +Pass a pointer to a function that matches the following prototype: +\fBsize_t function( char *ptr, size_t size, size_t nmemb, void *userdata);\fP +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 \fIptr\fP is \fIsize\fP +multiplied with \fInmemb\fP, it will not be zero terminated. 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 \fICURLE_WRITE_ERROR\fP. + +From 7.18.0, the function can return CURL_WRITEFUNC_PAUSE which then will +cause writing to this connection to become paused. See +\fIcurl_easy_pause(3)\fP for further details. + +This function may be called with zero bytes data if the 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 +\fICURLOPT_WRITEDATA\fP. + +Set the \fIuserdata\fP argument with the \fICURLOPT_WRITEDATA\fP 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 body data that can be passed to the write +callback is defined in the curl.h header file: CURL_MAX_WRITE_SIZE (the usual +default is 16K). If you however have \fICURLOPT_HEADER\fP set, which sends +header data to the write callback, you can get up to +\fICURL_MAX_HTTP_HEADER\fP bytes of header data passed into it. This usually +means 100K. +.IP CURLOPT_WRITEDATA +Data pointer to pass to the file write function. If you use the +\fICURLOPT_WRITEFUNCTION\fP option, 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. + +The internal \fICURLOPT_WRITEFUNCTION\fP 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 \fBMUST\fP use the +\fICURLOPT_WRITEFUNCTION\fP if you set this option or you will experience +crashes. + +This option is also known with the older name \fICURLOPT_FILE\fP, the name +\fICURLOPT_WRITEDATA\fP was introduced in 7.9.7. +.IP CURLOPT_READFUNCTION +Pass a pointer to a function that matches the following prototype: +\fBsize_t function( void *ptr, size_t size, size_t nmemb, void *userdata);\fP +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 \fIptr\fP may +be filled with at most \fIsize\fP multiplied with \fInmemb\fP 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 come. + +The read callback may return \fICURL_READFUNC_ABORT\fP to stop the current +operation immediately, resulting in a \fICURLE_ABORTED_BY_CALLBACK\fP 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 \fIcurl_easy_pause(3)\fP +for further details. + +\fBBugs\fP: when doing TFTP uploads, you must return the exact amount of data +that the callback wants, or it will be considered the final packet by the +server end and the transfer will end there. + +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 \fICURLOPT_READDATA\fP. +.IP CURLOPT_READDATA +Data pointer to pass to the file read function. If you use the +\fICURLOPT_READFUNCTION\fP 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 +\fICURLOPT_READFUNCTION\fP if you set this option. + +This option was also known by the older name \fICURLOPT_INFILE\fP, the name +\fICURLOPT_READDATA\fP was introduced in 7.9.7. +.IP CURLOPT_IOCTLFUNCTION +Pass a pointer to a function that matches the following prototype: +\fBcurlioerr function(CURL *handle, int cmd, void *clientp);\fP. 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 \fICURLOPT_SEEKFUNCTION\fP instead to provide seeking! +.IP CURLOPT_IOCTLDATA +Pass a pointer that will be untouched by libcurl and passed as the 3rd +argument in the ioctl callback set with \fICURLOPT_IOCTLFUNCTION\fP. (Option +added in 7.12.3) +.IP CURLOPT_SEEKFUNCTION +Pass a pointer to a function that matches the following prototype: \fBint +function(void *instream, curl_off_t offset, int origin);\fP This function gets +called by libcurl 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 \fIoffset\fP is not the same as defined for curl_off_t on +many systems! (Option added in 7.18.0) +.IP CURLOPT_SEEKDATA +Data pointer to pass to the file seek function. If you use the +\fICURLOPT_SEEKFUNCTION\fP 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) +.IP CURLOPT_SOCKOPTFUNCTION +Pass a pointer to a function that matches the following prototype: \fBint +function(void *clientp, curl_socket_t curlfd, curlsocktype purpose);\fP. This +function gets called by libcurl after the socket() call but before the +connect() call. The callback's \fIpurpose\fP argument identifies the exact +purpose for this particular socket: + +\fICURLSOCKTYPE_IPCXN\fP for actively created connections or since 7.28.0 +\fICURLSOCKTYPE_ACCEPT\fP for FTP when the connection was setup with PORT/EPSV +(in earlier versions these sockets weren't passed to this callback). + +Future versions of libcurl may support more purposes. It passes the newly +created socket descriptor so additional setsockopt() calls can be done at the +user's discretion. Return 0 (zero) from the callback on success. Return 1 +from the callback function to signal an unrecoverable error to the library and +it will close the socket and return \fICURLE_COULDNT_CONNECT\fP. (Option +added in 7.16.0) + +Added in 7.21.5, the callback function may return +\fICURL_SOCKOPT_ALREADY_CONNECTED\fP, which tells libcurl that the socket is +in fact already connected and then libcurl will not attempt to connect it. +.IP CURLOPT_SOCKOPTDATA +Pass a pointer that will be untouched by libcurl and passed as the first +argument in the sockopt callback set with \fICURLOPT_SOCKOPTFUNCTION\fP. +(Option added in 7.16.0) +.IP CURLOPT_OPENSOCKETFUNCTION +Pass a pointer to a function that matches the following prototype: +\fBcurl_socket_t function(void *clientp, curlsocktype purpose, struct +curl_sockaddr *address);\fP. This function gets called by libcurl instead of +the \fIsocket(2)\fP call. The callback's \fIpurpose\fP argument identifies the +exact purpose for this particular socket: \fICURLSOCKTYPE_IPCXN\fP is for IP +based connections. Future versions of libcurl may support more purposes. It +passes the resolved peer address as a \fIaddress\fP argument so the callback +can modify the address or refuse to connect at all. The callback function +should return the socket or \fICURL_SOCKET_BAD\fP in case no connection could +be established or another error was detected. Any additional +\fIsetsockopt(2)\fP calls can be done on the socket at the user's discretion. +\fICURL_SOCKET_BAD\fP return value from the callback function will signal an +unrecoverable error to the library and it will return +\fICURLE_COULDNT_CONNECT\fP. This return code can be used for IP address +blacklisting. The default behavior is: +.nf + return socket(addr->family, addr->socktype, addr->protocol); +.fi +(Option added in 7.17.1.) +.IP CURLOPT_OPENSOCKETDATA +Pass a pointer that will be untouched by libcurl and passed as the first +argument in the opensocket callback set with \fICURLOPT_OPENSOCKETFUNCTION\fP. +(Option added in 7.17.1.) +.IP CURLOPT_CLOSESOCKETFUNCTION +Pass a pointer to a function that matches the following prototype: \fBint +function(void *clientp, curl_socket_t item);\fP. This function gets called by +libcurl instead of the \fIclose(3)\fP or \fIclosesocket(3)\fP call when +sockets are closed (not for any other file descriptors). This is pretty much +the reverse to the \fICURLOPT_OPENSOCKETFUNCTION\fP option. Return 0 to signal +success and 1 if there was an error. (Option added in 7.21.7) +.IP CURLOPT_CLOSESOCKETDATA +Pass a pointer that will be untouched by libcurl and passed as the first +argument in the closesocket callback set with +\fICURLOPT_CLOSESOCKETFUNCTION\fP. (Option added in 7.21.7) +.IP CURLOPT_PROGRESSFUNCTION +Pass a pointer to a function that matches the following prototype: \fBint +function(void *clientp, double dltotal, double dlnow, double ultotal, double +ulnow); \fP. 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 transferred 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 +\fICURLE_ABORTED_BY_CALLBACK\fP. + +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. + +\fICURLOPT_NOPROGRESS\fP must be set to 0 to make this function actually +get called. +.IP CURLOPT_PROGRESSDATA +Pass a pointer that will be untouched by libcurl and passed as the first +argument in the progress callback set with \fICURLOPT_PROGRESSFUNCTION\fP. +.IP CURLOPT_HEADERFUNCTION +Pass a pointer to a function that matches the following prototype: +\fBsize_t function( void *ptr, size_t size, size_t nmemb, void +*userdata);\fP. 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 callback. Parsing headers +is very easy using this. The size of the data pointed to by \fIptr\fP is +\fIsize\fP multiplied with \fInmemb\fP. Do not assume that the header line is +zero terminated! The pointer named \fIuserdata\fP is the one you set with the +\fICURLOPT_WRITEHEADER\fP option. The callback 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 \fICURL_WRITE_ERROR\fP. + +A complete HTTP header that is passed to this function can be up to +\fICURL_MAX_HTTP_HEADER\fP (100K) bytes. + +If this option is not set, or if it is set to NULL, but +\fICURLOPT_HEADERDATA\fP (\fICURLOPT_WRITEHEADER\fP) is set to anything but +NULL, the function used to accept response data will be used instead. That is, +it will be the function specified with \fICURLOPT_WRITEFUNCTION\fP, 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 authentication +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 boundaries. + +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 regular response-headers mention what header(s) to expect in +the trailer. + +For non-HTTP protocols like FTP, POP3, IMAP and SMTP this function will get +called with the server responses to the commands that libcurl sends. +.IP CURLOPT_WRITEHEADER +(This option is also known as \fBCURLOPT_HEADERDATA\fP) Pass a pointer to be +used to write the header part of the received data to. If you don't use +\fICURLOPT_WRITEFUNCTION\fP or \fICURLOPT_HEADERFUNCTION\fP to take care of +the writing, this must be a valid FILE * as the internal default will then be +a plain fwrite(). See also the \fICURLOPT_HEADERFUNCTION\fP option above on +how to set a custom get-all-headers callback. +.IP CURLOPT_DEBUGFUNCTION +Pass a pointer to a function that matches the following prototype: \fBint +curl_debug_callback (CURL *, curl_infotype, char *, size_t, void *);\fP +\fICURLOPT_DEBUGFUNCTION\fP replaces the standard debug function used when +\fICURLOPT_VERBOSE \fP is in effect. This callback receives debug information, +as specified with the \fBcurl_infotype\fP argument. This function must return +0. The data pointed to by the char * passed to this function WILL NOT be zero +terminated, but will be exactly of the size as told by the size_t argument. + +Available curl_infotype values: +.RS +.IP CURLINFO_TEXT +The data is informational text. +.IP CURLINFO_HEADER_IN +The data is header (or header-like) data received from the peer. +.IP CURLINFO_HEADER_OUT +The data is header (or header-like) data sent to the peer. +.IP CURLINFO_DATA_IN +The data is protocol data received from the peer. +.IP CURLINFO_DATA_OUT +The data is protocol data sent to the peer. +.RE +.IP CURLOPT_DEBUGDATA +Pass a pointer to whatever you want passed in to your +\fICURLOPT_DEBUGFUNCTION\fP in the last void * argument. This pointer is not +used by libcurl, it is only passed to the callback. +.IP 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. + +Pass a pointer to a function that matches the following prototype: +\fBCURLcode sslctxfun(CURL *curl, void *sslctx, void *parm);\fP This function +gets called by libcurl just before the initialization of a 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 +\fIsslctx\fP parameter is actually a pointer to an openssl \fISSL_CTX\fP. 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 \fIparm\fP argument with the \fICURLOPT_SSL_CTX_DATA\fP 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 a HTTPS request (example used in the lib509 test +case). See also the example section for a replacement of the key, certificate +and trust file settings. +.IP CURLOPT_SSL_CTX_DATA +Data pointer to pass to the ssl context callback set by the option +\fICURLOPT_SSL_CTX_FUNCTION\fP, this is the pointer you'll get as third +parameter, otherwise \fBNULL\fP. (Added in 7.11.0) +.IP CURLOPT_CONV_TO_NETWORK_FUNCTION +.IP CURLOPT_CONV_FROM_NETWORK_FUNCTION +.IP CURLOPT_CONV_FROM_UTF8_FUNCTION +Pass a pointer to a function that matches the following prototype: +\fBCURLcode function(char *ptr, size_t length);\fP + +These three options apply to non-ASCII platforms only. They are available +only if \fBCURL_DOES_CONVERSIONS\fP was defined when libcurl was built. When +this is the case, \fIcurl_version_info(3)\fP 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 successful conversion. A CURLcode return +value defined by curl.h, such as CURLE_CONV_FAILED, should be returned if an +error was encountered. + +\fBCURLOPT_CONV_TO_NETWORK_FUNCTION\fP and +\fBCURLOPT_CONV_FROM_NETWORK_FUNCTION\fP convert between the host encoding and +the network encoding. They are used when commands or ASCII data are +sent/received over the network. + +\fBCURLOPT_CONV_FROM_UTF8_FUNCTION\fP 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. +.IP CURLOPT_INTERLEAVEFUNCTION +Pass a pointer to a function that matches the following prototype: +\fBsize_t function( void *ptr, size_t size, size_t nmemb, void +*userdata)\fP. 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 interleaved 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 identifier and then a 2 byte integer length in network byte +order. See \fIRFC2326 Section 10.12\fP 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 challenges 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 unreasonably delayed and the +connection may close. The application may use \fICURL_RTSPREQ_RECEIVE\fP to +service RTP data when no requests are desired. If the application makes a +request, (e.g. \fICURL_RTSPREQ_PAUSE\fP) then the response handler will +process any pending RTP data before marking the request as finished. (Added +in 7.20.0) +.IP CURLOPT_INTERLEAVEDATA +This is the userdata pointer that will be passed to +\fICURLOPT_INTERLEAVEFUNCTION\fP when interleaved RTP data is received. (Added +in 7.20.0) +.IP CURLOPT_CHUNK_BGN_FUNCTION +Pass a pointer to a function that matches the following prototype: +\fBlong function (const void *transfer_info, void *ptr, int remains)\fP. This +function gets called by libcurl before a part of the stream is going to be +transferred (if the transfer supports chunks). + +This callback makes sense only when using the \fICURLOPT_WILDCARDMATCH\fP +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 +\fIcurl/curl.h\fP). The parameter ptr is a pointer given by +\fICURLOPT_CHUNK_DATA\fP. The parameter remains contains number of chunks +remaining per the transfer. If the feature is not available, the parameter has +zero value. + +Return \fICURL_CHUNK_BGN_FUNC_OK\fP if everything is fine, +\fICURL_CHUNK_BGN_FUNC_SKIP\fP if you want to skip the concrete chunk or +\fICURL_CHUNK_BGN_FUNC_FAIL\fP to tell libcurl to stop if some error occurred. +(This was added in 7.21.0) +.IP CURLOPT_CHUNK_END_FUNCTION +Pass a pointer to a function that matches the following prototype: +\fBlong function(void *ptr)\fP. This function gets called by libcurl as soon +as a part of the stream has been transferred (or skipped). + +Return \fICURL_CHUNK_END_FUNC_OK\fP if everything is fine or +\fBCURL_CHUNK_END_FUNC_FAIL\fP to tell the lib to stop if some error occurred. +(This was added in 7.21.0) +.IP CURLOPT_CHUNK_DATA +Pass a pointer that will be untouched by libcurl and passed as the ptr +argument to the \fICURL_CHUNK_BGN_FUNTION\fP and \fICURL_CHUNK_END_FUNTION\fP. +(This was added in 7.21.0) +.IP CURLOPT_FNMATCH_FUNCTION +Pass a pointer to a function that matches the following prototype: \fBint +function(void *ptr, const char *pattern, const char *string)\fP prototype (see +\fIcurl/curl.h\fP). It is used internally for the wildcard matching feature. + +Return \fICURL_FNMATCHFUNC_MATCH\fP if pattern matches the string, +\fICURL_FNMATCHFUNC_NOMATCH\fP if not or \fICURL_FNMATCHFUNC_FAIL\fP if an +error occurred. (This was added in 7.21.0) +.IP CURLOPT_FNMATCH_DATA +Pass a pointer that will be untouched by libcurl and passed as the ptr argument +to the \fICURL_FNMATCH_FUNCTION\fP. (This was added in 7.21.0) +.SH ERROR OPTIONS +.IP 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 +\fIcurl_easy_perform\fP. 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 must 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 \fIcurl_easy_cleanup(3)\fP or you +set the same option again to use a different pointer. + +Use \fICURLOPT_VERBOSE\fP and \fICURLOPT_DEBUGFUNCTION\fP 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. + +.IP CURLOPT_STDERR +Pass a FILE * as parameter. Tell libcurl to use this stream instead of stderr +when showing the progress meter and displaying \fICURLOPT_VERBOSE\fP data. +.IP 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 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. +.SH NETWORK OPTIONS +.IP CURLOPT_URL +Pass in a pointer to the actual URL to deal with. The parameter should be a +char * to a zero terminated string which must be URL-encoded in the following +format: + +scheme://host:port/path + +For a greater explanation of the format please see RFC3986. + +If the given URL lacks the scheme, or protocol, part ("http://" or "ftp://" +etc), libcurl will attempt to resolve which protocol to use based on the +given host mame. If the protocol is not supported, libcurl will return +(\fICURLE_UNSUPPORTED_PROTOCOL\fP) when you call \fIcurl_easy_perform(3)\fP +or \fIcurl_multi_perform(3)\fP. Use \fIcurl_version_info(3)\fP for detailed +information on which protocols are supported. + +The host part of the URL contains the address of the server that you want to +connect to. This can be the fully qualified domain name of the server, the +local network name of the machine on your network or the IP address of the +server or machine represented by either an IPv4 or IPv6 address. For example: + +http://www.example.com/ + +http://hostname/ + +http://192.168.0.1/ + +http://[2001:1890:1112:1::20]/ + +It is also possible to specify the user name and password as part of the +host, for some protocols, when connecting to servers that require +authentication. + +For example the following types of authentication support this: + +http://user:password@www.example.com + +ftp://user:password@ftp.example.com + +pop3://user:password@mail.example.com + +The port is optional and when not specified libcurl will use the default port +based on the determined or specified protocol: 80 for HTTP, 21 for FTP and 25 +for SMTP, etc. The following examples show how to specify the port: + +http://www.example.com:8080/ - This will connect to a web server using port +8080 rather than 80. + +smtp://mail.example.com:587/ - This will connect to a SMTP server on the +alternative mail port. + +The path part of the URL is protocol specific and whilst some examples are +given below this list is not conclusive: + +.B HTTP + +The path part of a HTTP request specifies the file to retrieve and from what +directory. If the directory is not specified then the web server's root +directory is used. If the file is omitted then the default document will be +retrieved for either the directory specified or the root directory. The +exact resource returned for each URL is entirely dependent on the server's +configuration. + +http://www.example.com - This gets the main page from the web server. + +http://www.example.com/index.html - This returns the main page by explicitly +requesting it. + +http://www.example.com/contactus/ - This returns the default document from +the contactus directory. + +.B FTP + +The path part of an FTP request specifies the file to retrieve and from what +directory. If the file part is omitted then libcurl downloads the directory +listing for the directory specified. If the directory is omitted then +the directory listing for the root / home directory will be returned. + +ftp://ftp.example.com - This retrieves the directory listing for the root +directory. + +ftp://ftp.example.com/readme.txt - This downloads the file readme.txt from the +root directory. + +ftp://ftp.example.com/libcurl/readme.txt - This downloads readme.txt from the +libcurl directory. + +ftp://user:password@ftp.example.com/readme.txt - This retrieves the readme.txt +file from the user's home directory. When a username and password is +specified, everything that is specified in the path part is relative to the +user's home directory. To retrieve files from the root directory or a +directory underneath the root directory then the absolute path must be +specified by prepending an additional forward slash to the beginning of the +path. + +ftp://user:password@ftp.example.com//readme.txt - This retrieves the readme.txt +from the root directory when logging in as a specified user. + +.B SMTP + +The path part of a SMTP request specifies the host name to present during +communication with the mail server. If the path is omitted then libcurl will +attempt to resolve the local computer's host name. However, this may not +return the fully qualified domain name that is required by some mail servers +and specifying this path allows you to set an alternative name, such as +your machine's fully qualified domain name, which you might have obtained +from an external function such as gethostname or getaddrinfo. + +smtp://mail.example.com - This connects to the mail server at example.com and +sends your local computer's host name in the HELO / EHLO command. + +smtp://mail.example.com/client.example.com - This will send client.example.com in +the HELO / EHLO command to the mail server at example.com. + +.B POP3 + +The path part of a POP3 request specifies the mailbox (message) to retrieve. +If the mailbox is not specified then a list of waiting messages is returned +instead. + +pop3://user:password@mail.example.com - This lists the available messages +pop3://user:password@mail.example.com/1 - This retrieves the first message + +.B SCP + +The path part of a SCP request specifies the file to retrieve and from what +directory. The file part may not be omitted. The file is taken as an absolute +path from the root directory on the server. To specify a path relative to +the user's home directory on the server, prepend ~/ to the path portion. +If the user name is not embedded in the URL, it can be set with the +\fICURLOPT_USERPWD\fP or \fBCURLOPT_USERNAME\fP option. + +scp://user@example.com/etc/issue - This specifies the file /etc/issue + +scp://example.com/~/my-file - This specifies the file my-file in the +user's home directory on the server + +.B SFTP + +The path part of a SFTP request specifies the file to retrieve and from what +directory. If the file part is omitted then libcurl downloads the directory +listing for the directory specified. If the path ends in a / then a directory +listing is returned instead of a file. If the path is omitted entirely then +the directory listing for the root / home directory will be returned. +If the user name is not embedded in the URL, it can be set with the +\fICURLOPT_USERPWD\fP or \fBCURLOPT_USERNAME\fP option. + +sftp://user:password@example.com/etc/issue - This specifies the file +/etc/issue + +sftp://user@example.com/~/my-file - This specifies the file my-file in the +user's home directory + +sftp://ssh.example.com/~/Documents/ - This requests a directory listing +of the Documents directory under the user's home directory + +.B LDAP + +The path part of a LDAP request can be used to specify the: Distinguished +Name, Attributes, Scope, Filter and Extension for a LDAP search. Each field +is separated by a question mark and when that field is not required an empty +string with the question mark separator should be included. + +ldap://ldap.example.com/o=My%20Organisation - This will perform a LDAP search +with the DN as My Organisation. + +ldap://ldap.example.com/o=My%20Organisation?postalAddress - This will perform +the same search but will only return postalAddress attributes. + +ldap://ldap.example.com/?rootDomainNamingContext - This specifies an empty DN +and requests information about the rootDomainNamingContext attribute for an +Active Directory server. + +For more information about the individual components of a LDAP URL please +see RFC4516. + +.B NOTES + +Starting with version 7.20.0, the fragment part of the URI will not be sent as +part of the path, which was previously the case. + +\fICURLOPT_URL\fP is the only option that \fBmust\fP be set before +\fIcurl_easy_perform(3)\fP is called. + +\fICURLOPT_PROTOCOLS\fP 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 useful if you accept the URL from an external source and +want to limit the accessibility. +.IP 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 protocols 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 +\fICURLOPT_REDIR_PROTOCOLS\fP. (Added in 7.19.4) +.IP CURLOPT_REDIR_PROTOCOLS +Pass a long that holds a bitmask of CURLPROTO_* defines. If used, this bitmask +limits what protocols libcurl may use in a transfer that it follows to in a +redirect when \fICURLOPT_FOLLOWLOCATION\fP 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) +.IP 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. +\fICURLOPT_PROXYPORT\fP. + +When you tell the library to use a 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 +\fICURLOPT_QUOTE\fP and similar FTP specifics that don't work unless you +tunnel through the HTTP proxy. Such tunneling is activated with +\fICURLOPT_HTTPPROXYTUNNEL\fP. + +libcurl respects the environment variables \fBhttp_proxy\fP, \fBftp_proxy\fP, +\fBall_proxy\fP etc, if any of those are set. The \fICURLOPT_PROXY\fP 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 environment variables can be +specified the exact same way as the proxy can be set with \fICURLOPT_PROXY\fP, +include protocol prefix (http://) and embedded user + password. + +Since 7.21.7, the proxy string may be specified with a protocol:// prefix to +specify alternative proxy protocols. Use socks4://, socks4a://, socks5:// or +socks5h:// (the last one to enable socks5 and asking the proxy to do the +resolving, also known as CURLPROXY_SOCKS5_HOSTNAME type) to request the +specific SOCKS version to be used. No protocol specified, http:// and all +others will be treated as HTTP proxies. +.IP CURLOPT_PROXYPORT +Pass a long with this option to set the proxy port to connect to unless it is +specified in the proxy string \fICURLOPT_PROXY\fP. +.IP CURLOPT_PROXYTYPE +Pass a long with this option to set type of the proxy. Available options for +this are \fICURLPROXY_HTTP\fP, \fICURLPROXY_HTTP_1_0\fP (added in 7.19.4), +\fICURLPROXY_SOCKS4\fP (added in 7.10), \fICURLPROXY_SOCKS5\fP, +\fICURLPROXY_SOCKS4A\fP (added in 7.18.0) and \fICURLPROXY_SOCKS5_HOSTNAME\fP +(added in 7.18.0). The HTTP type is default. (Added in 7.10) + +If you set \fBCURLOPT_PROXYTYPE\fP to \fICURLPROXY_HTTP_1_0\fP, it will only +affect how libcurl speaks to a proxy when CONNECT is used. The HTTP version +used for "regular" HTTP requests is instead controlled with +\fICURLOPT_HTTP_VERSION\fP. +.IP CURLOPT_NOPROXY +Pass a pointer to a zero terminated string. The string consists of a comma +separated list of host names that do not require a proxy to get reached, even +if one is specified. The only wildcard available is a single * character, +which matches all hosts, and effectively disables the proxy. Each name in this +list is matched as either a domain which contains the hostname, or the +hostname itself. For example, example.com would match example.com, +example.com:80, and www.example.com, but not www.notanexample.com. (Added in +7.19.4) +.IP 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. +.IP 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) +.IP 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 negotiated. 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). +.IP 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. + +Starting with 7.24.0: If the parameter starts with "if!" then it is treated as +only as interface name and no attempt will ever be named to do treat it as an +IP address or to do name resolution on it. If the parameter starts with +\&"host!" it is treated as either an IP address or a hostname. Hostnames are +resolved synchronously. Using the if! format is highly recommended when using +the multi interfaces to avoid allowing the code to block. If "if!" is +specified but the parameter does not match an existing interface, +CURLE_INTERFACE_FAILED is returned. +.IP CURLOPT_LOCALPORT +Pass a long. This sets the local port number of the socket used for +connection. This can be used in combination with \fICURLOPT_INTERFACE\fP and +you are recommended to use \fICURLOPT_LOCALPORTRANGE\fP as well when this is +set. Valid port numbers are 1 - 65535. (Added in 7.15.2) +.IP CURLOPT_LOCALPORTRANGE +Pass a long. This is the number of attempts libcurl will make to find a +working local port number. It starts with the given \fICURLOPT_LOCALPORT\fP +and adds one to 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) +.IP 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 implementations don't re-read name +server information unless explicitly told so (for example, by calling +\fIres_init(3)\fP). 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. +.IP 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. + +\fBWARNING:\fP this option is considered obsolete. Stop using it. Switch over +to using the share interface instead! See \fICURLOPT_SHARE\fP and +\fIcurl_share_init(3)\fP. +.IP 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. +.IP CURLOPT_PORT +Pass a long specifying what remote port number to connect to, instead of the +one specified in the URL or the default port for the used protocol. +.IP CURLOPT_TCP_NODELAY +Pass a long specifying whether the TCP_NODELAY option is to be set or cleared +(1 = set, 0 = clear). The 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 Segment 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 network if overdone. +.IP 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) +.IP CURLOPT_TCP_KEEPALIVE +Pass a long. If set to 1, TCP keepalive probes will be sent. The delay and +frequency of these probes can be controlled by the \fICURLOPT_TCP_KEEPIDLE\fP +and \fICURLOPT_TCP_KEEPINTVL\fP options, provided the operating system supports +them. Set to 0 (default behavior) to disable keepalive probes (Added in +7.25.0). +.IP CURLOPT_TCP_KEEPIDLE +Pass a long. Sets the delay, in seconds, that the operating system will wait +while the connection is idle before sending keepalive probes. Not all operating +systems support this option. (Added in 7.25.0) +.IP CURLOPT_TCP_KEEPINTVL +Pass a long. Sets the interval, in seconds, that the operating system will wait +between sending keepalive probes. Not all operating systems support this +option. (Added in 7.25.0) +.SH NAMES and PASSWORDS OPTIONS (Authentication) +.IP CURLOPT_NETRC +This parameter controls the preference of libcurl between using user names and +passwords from your \fI~/.netrc\fP file, relative to user names and passwords +in the URL supplied with \fICURLOPT_URL\fP. + +libcurl uses a user name (and supplied or prompted password) supplied with +\fICURLOPT_USERPWD\fP in preference to any of the options controlled by this +parameter. + +Pass a long, set to one of the values described below. +.RS +.IP CURL_NETRC_OPTIONAL +The use of your \fI~/.netrc\fP 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 \fImachine\fP, which ever information is not specified in +the URL. + +Undefined values of the option will have this effect. +.IP CURL_NETRC_IGNORED +The library will ignore the file and use only the information in the URL. + +This is the default. +.IP 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. +.RE +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 properties set (as the +standard Unix ftp client does). It should only be readable by user. +.IP CURLOPT_NETRC_FILE +Pass a char * as parameter, pointing to a zero terminated string containing +the full path name to the file you want libcurl to use as .netrc file. If this +option is omitted, and \fICURLOPT_NETRC\fP is set, libcurl will attempt to +find a .netrc file in the current user's home directory. (Added in 7.10.9) +.IP CURLOPT_USERPWD +Pass a char * as parameter, which should be [user name]:[password] to use for +the connection. Use \fICURLOPT_HTTPAUTH\fP 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 \fICURLOPT_FOLLOWLOCATION\fP, 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 +\fICURLOPT_UNRESTRICTED_AUTH\fP is set), so if libcurl follows locations to +other hosts it will not send the user and password to those. This is enforced +to prevent accidental information leakage. +.IP CURLOPT_PROXYUSERPWD +Pass a char * as parameter, which should be [user name]:[password] to use for +the connection to the HTTP proxy. Use \fICURLOPT_PROXYAUTH\fP to decide +the authentication method. +.IP CURLOPT_USERNAME +Pass a char * as parameter, which should be pointing to the zero terminated +user name to use for the transfer. + +\fBCURLOPT_USERNAME\fP sets the user name to be used in protocol +authentication. You should not use this option together with the (older) +CURLOPT_USERPWD option. + +In order to specify the password to be used in conjunction with the user name +use the \fICURLOPT_PASSWORD\fP option. (Added in 7.19.1) +.IP 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 conjunction with +the \fICURLOPT_USERNAME\fP option. (Added in 7.19.1) +.IP 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 +\fICURLOPT_PROXYUSERPWD\fP is used. In comparison to +\fICURLOPT_PROXYUSERPWD\fP 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 +\fICURLOPT_PROXYUSERPWD\fP option. + +In order to specify the password to be used in conjunction with the user name +use the \fICURLOPT_PROXYPASSWORD\fP option. (Added in 7.19.1) +.IP 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 conjunction with +the \fICURLOPT_PROXYUSERNAME\fP option. (Added in 7.19.1) +.IP 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 \fICURLOPT_USERPWD\fP option or +with the \fICURLOPT_USERNAME\fP and the \fICURLOPT_PASSWORD\fP options. +(Added in 7.10.6) +.RS +.IP 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. +.IP 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. +.IP 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) +.IP 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. +.IP 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 eavesdropped. + +You need to build libcurl with either OpenSSL, GnuTLS or NSS support for this +option to work, or build libcurl on Windows. +.IP CURLAUTH_NTLM_WB +NTLM delegating to winbind helper. Authentication is performed by a separate +binary application that is executed when needed. The name of the application +is specified at compile time but is typically /usr/bin/ntlm_auth +(Added in 7.22.0) + +Note that libcurl will fork when necessary to run the winbind application and +kill it when complete, calling waitpid() to await its exit when done. On POSIX +operating systems, killing the process will cause a SIGCHLD signal to be +raised (regardless of whether \fICURLOPT_NOSIGNAL\fP is set), which must be +handled intelligently by the application. In particular, the application must +not unconditionally call wait() in its SIGCHLD signal handler to avoid being +subject to a race condition. This behavior is subject to change in future +versions of libcurl. +.IP CURLAUTH_ANY +This is a convenience macro that sets all bits and thus makes libcurl pick any +it finds suitable. libcurl will automatically select the one it finds most +secure. +.IP 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. +.IP CURLAUTH_ONLY +This is a meta symbol. Or this value together with a single specific auth +value to force libcurl to probe for un-restricted auth and if not, only that +single auth algorithm is acceptable. (Added in 7.21.3) +.RE +.IP CURLOPT_TLSAUTH_TYPE +Pass a long as parameter, which is set to a bitmask, to tell libcurl which +authentication method(s) you want it to use for TLS authentication. +.RS +.IP CURLOPT_TLSAUTH_SRP +TLS-SRP authentication. Secure Remote Password authentication for TLS is +defined in RFC5054 and provides mutual authentication if both sides have a +shared secret. To use TLS-SRP, you must also set the +\fICURLOPT_TLSAUTH_USERNAME\fP and \fICURLOPT_TLSAUTH_PASSWORD\fP options. + +You need to build libcurl with GnuTLS or OpenSSL with TLS-SRP support for this +to work. (Added in 7.21.4) +.RE +.IP CURLOPT_TLSAUTH_USERNAME +Pass a char * as parameter, which should point to the zero terminated username +to use for the TLS authentication method specified with the +\fICURLOPT_TLSAUTH_TYPE\fP option. Requires that the +\fICURLOPT_TLS_PASSWORD\fP option also be set. (Added in 7.21.4) +.IP CURLOPT_TLSAUTH_PASSWORD +Pass a char * as parameter, which should point to the zero terminated password +to use for the TLS authentication method specified with the +\fICURLOPT_TLSAUTH_TYPE\fP option. Requires that the +\fICURLOPT_TLS_USERNAME\fP option also be set. (Added in 7.21.4) +.IP 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 \fICURLOPT_PROXYUSERPWD\fP option. The +bitmask can be constructed by or'ing together the bits listed above for the +\fICURLOPT_HTTPAUTH\fP option. As of this writing, only Basic, Digest and NTLM +work. (Added in 7.10.7) +.SH HTTP OPTIONS +.IP 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. +.IP CURLOPT_ACCEPT_ENCODING +Sets the contents of the Accept-Encoding: header sent in a HTTP request, and +enables decoding of a response when a Content-Encoding: header is received. +Three encodings are supported: \fIidentity\fP, which does nothing, +\fIdeflate\fP which requests the server to compress its response using the +zlib algorithm, and \fIgzip\fP which requests the gzip algorithm. If a +zero-length string is set, then an Accept-Encoding: header containing all +supported encodings is sent. + +This is a request, not an order; the server may or may not do it. This option +must be set (to any non-NULL value) or else any unsolicited encoding done by +the server is ignored. See the special file lib/README.encoding for details. + +(This option was called CURLOPT_ENCODING before 7.21.6) +.IP CURLOPT_TRANSFER_ENCODING +Adds a request for compressed Transfer Encoding in the outgoing HTTP +request. If the server supports this and so desires, it can respond with the +HTTP response sent using a compressed Transfer-Encoding that will be +automatically uncompressed by libcurl on reception. + +Transfer-Encoding differs slightly from the Content-Encoding you ask for with +\fBCURLOPT_ACCEPT_ENCODING\fP in that a Transfer-Encoding is strictly meant to +be for the transfer and thus MUST be decoded before the data arrives in the +client. Traditionally, Transfer-Encoding has been much less used and supported +by both HTTP clients and HTTP servers. + +(Added in 7.21.6) +.IP CURLOPT_FOLLOWLOCATION +A parameter set to 1 tells the library to follow any Location: header that the +server sends as part of a HTTP header. + +This means that the library will re-send the same request on the new location +and follow new Location: headers all the way until no more such headers are +returned. \fICURLOPT_MAXREDIRS\fP can be used to limit the number of redirects +libcurl will follow. + +Since 7.19.4, libcurl can limit what protocols it will automatically +follow. The accepted protocols are set with \fICURLOPT_REDIR_PROTOCOLS\fP and +it excludes the FILE protocol by default. +.IP 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 \fICURLOPT_FOLLOWLOCATION\fP. +.IP CURLOPT_MAXREDIRS +Pass a long. The set number will be the redirection limit. If that many +redirections have been followed, the next redirect will cause an error +(\fICURLE_TOO_MANY_REDIRECTS\fP). This option only makes sense if the +\fICURLOPT_FOLLOWLOCATION\fP is used at the same time. 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) +.IP CURLOPT_POSTREDIR +Pass a bitmask to control how libcurl acts on redirects after POSTs that get a +301, 302 or 303 response back. A parameter with bit 0 set (value +\fBCURL_REDIR_POST_301\fP) tells the library to respect RFC2616/10.3.2 and not +convert POST requests into GET requests when following a 301 redirection. +Setting bit 1 (value \fBCURL_REDIR_POST_302\fP) makes libcurl maintain the +request method after a 302 redirect whilst setting bit 2 (value +\fBCURL_REDIR_POST_303\fP) makes libcurl maintain the request method after a +303 redirect. The value \fBCURL_REDIR_POST_ALL\fP is a convenience define that +sets all three 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 \fICURLOPT_FOLLOWLOCATION\fP. (Added in 7.17.1) (This option was +known as CURLOPT_POST301 up to 7.19.0 as it only supported the 301 then) +.IP CURLOPT_PUT +A parameter set to 1 tells the library to use HTTP PUT to transfer data. The +data should be set with \fICURLOPT_READDATA\fP and \fICURLOPT_INFILESIZE\fP. + +This option is deprecated and starting with version 7.12.1 you should instead +use \fICURLOPT_UPLOAD\fP. +.IP 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 \fICURLOPT_POSTFIELDS\fP or \fICURLOPT_COPYPOSTFIELDS\fP options to +specify what data to post and \fICURLOPT_POSTFIELDSIZE\fP or +\fICURLOPT_POSTFIELDSIZE_LARGE\fP to set the data size. + +Optionally, you can provide data to POST using the \fICURLOPT_READFUNCTION\fP +and \fICURLOPT_READDATA\fP options but then you must make sure to not set +\fICURLOPT_POSTFIELDS\fP to anything but NULL. When providing data with a +callback, you must transmit it using chunked transfer-encoding or you must set +the size of the data with the \fICURLOPT_POSTFIELDSIZE\fP or +\fICURLOPT_POSTFIELDSIZE_LARGE\fP 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 \fICURLOPT_HTTPHEADER\fP. + +Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" header. +You can disable this header with \fICURLOPT_HTTPHEADER\fP 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 +\fICURLOPT_HTTPHEADER\fP. With HTTP 1.0 or without chunked transfer, you must +specify the size in the request. + +When setting \fICURLOPT_POST\fP to 1, it will automatically set +\fICURLOPT_NOBODY\fP 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 +\fICURLOPT_NOBODY\fP or \fICURLOPT_HTTPGET\fP or similar. +.IP CURLOPT_POSTFIELDS +Pass a void * as parameter, which should be the full data to post in a 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 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 \fICURLOPT_POST\fP. Using +\fICURLOPT_POSTFIELDS\fP implies \fICURLOPT_POST\fP. + +If you want to do a zero-byte POST, you need to set +\fICURLOPT_POSTFIELDSIZE\fP explicitly to zero, as simply setting +\fICURLOPT_POSTFIELDS\fP to NULL or "" just effectively 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 \fICURLOPT_HTTPHEADER\fP as usual. + +To make multipart/formdata posts (aka RFC2388-posts), check out the +\fICURLOPT_HTTPPOST\fP option. +.IP 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. +.IP CURLOPT_POSTFIELDSIZE_LARGE +Pass a curl_off_t as parameter. Use this to set the size of the +\fICURLOPT_POSTFIELDS\fP data to prevent libcurl from doing strlen() on the +data to figure out the size. This is the large file version of the +\fICURLOPT_POSTFIELDSIZE\fP option. (Added in 7.11.1) +.IP CURLOPT_COPYPOSTFIELDS +Pass a char * as parameter, which should be the full data to post in a HTTP +POST operation. It behaves as the \fICURLOPT_POSTFIELDS\fP 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 \fICURLOPT_POSTFIELDSIZE\fP or +\fICURLOPT_POSTFIELDSIZE_LARGE\fP: If the size has not been set prior to +\fICURLOPT_COPYPOSTFIELDS\fP, 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 +\fICURLOPT_COPYPOSTFIELDS\fP, unless another \fICURLOPT_POSTFIELDS\fP or +\fICURLOPT_COPYPOSTFIELDS\fP option is issued. +(Added in 7.17.1) +.IP 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 \fIcurl_formadd(3)\fP as documented. The data in this list +must remain intact until you close this curl handle again with +\fIcurl_easy_cleanup(3)\fP. + +Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" header. +You can disable this header with \fICURLOPT_HTTPHEADER\fP as usual. + +When setting \fICURLOPT_HTTPPOST\fP, it will automatically set +\fICURLOPT_NOBODY\fP to 0 (since 7.14.1). +.IP CURLOPT_REFERER +Pass a pointer to a zero terminated string as parameter. It will be used to +set the Referer: header in the http request sent to the remote server. This +can be used to fool servers or scripts. You can also set any custom header +with \fICURLOPT_HTTPHEADER\fP. +.IP CURLOPT_USERAGENT +Pass a pointer to a zero terminated string as parameter. It will be used to +set the User-Agent: header in the http request sent to the remote server. This +can be used to fool servers or scripts. You can also set any custom header +with \fICURLOPT_HTTPHEADER\fP. +.IP CURLOPT_HTTPHEADER +Pass a pointer to a linked list of HTTP headers to pass to the server in your +HTTP request. The linked list should be a fully valid list of \fBstruct +curl_slist\fP structs properly filled in. Use \fIcurl_slist_append(3)\fP to +create the list and \fIcurl_slist_free_all(3)\fP to clean up an entire +list. If you add a header that is otherwise generated and used by libcurl +internally, your added one will be used instead. If you add a header with no +content 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. 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 +\fICURLOPT_COOKIE\fP, \fICURLOPT_USERAGENT\fP and \fICURLOPT_REFERER\fP. +.IP CURLOPT_HTTP200ALIASES +Pass a pointer to a linked list of aliases to be treated as valid HTTP 200 +responses. Some servers respond with a custom header response line. For +example, IceCast servers respond with "ICY 200 OK". By including this string +in your list of aliases, the response will be treated as a valid HTTP header +line such as "HTTP/1.0 200 OK". (Added in 7.10.3) + +The linked list should be a fully valid list of struct curl_slist structs, and +be properly filled in. Use \fIcurl_slist_append(3)\fP to create the list and +\fIcurl_slist_free_all(3)\fP to clean up an entire list. + +The alias itself is not parsed for any version strings. Before libcurl 7.16.3, +Libcurl used the value set by option \fICURLOPT_HTTP_VERSION\fP, but starting +with 7.16.3 the protocol is assumed to match HTTP 1.0 when an alias matched. +.IP CURLOPT_COOKIE +Pass a pointer to a zero terminated string as parameter. It will be used to +set a cookie in the http request. The format of the string should be +NAME=CONTENTS, where NAME is the cookie name and CONTENTS is what the cookie +should contain. + +If you need to set 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. + +This option sets the cookie header explicitly 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. +.IP CURLOPT_COOKIEFILE +Pass a pointer to a zero terminated string as parameter. It should contain the +name of your file holding cookie data to read. The cookie data may be in +Netscape / Mozilla cookie data format or just regular HTTP-style headers +dumped to a file. + +Given an empty or non-existing file 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. +.IP CURLOPT_COOKIEJAR +Pass a file name as char *, zero terminated. This will make libcurl write all +internally known cookies to the specified file when \fIcurl_easy_cleanup(3)\fP +is called. If no cookies are known, no file will be created. Specify "-" to +instead have the cookies written to stdout. Using this option also enables +cookies for this session, so if you for example follow a location it will make +matching cookies get sent accordingly. + +If the cookie jar file can't be created or written to (when the +\fIcurl_easy_cleanup(3)\fP is called), libcurl will not and cannot report an +error for this. Using \fICURLOPT_VERBOSE\fP or \fICURLOPT_DEBUGFUNCTION\fP +will get a warning to display, but that is the only visible feedback you get +about this possibly lethal situation. +.IP CURLOPT_COOKIESESSION +Pass a long set to 1 to mark this as a new cookie "session". 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. +.IP 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 \fICURLOPT_COOKIEJAR\fP. +(Added in 7.17.1) +.IP 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 \fICURLOPT_HTTPGET\fP to 1, it will automatically set +\fICURLOPT_NOBODY\fP to 0 (since 7.14.1). +.IP CURLOPT_HTTP_VERSION +Pass a long, set to one of the values described below. They force libcurl to +use the specific HTTP versions. This is not sensible to do unless you have a +good reason. +.RS +.IP CURL_HTTP_VERSION_NONE +We don't care about what version the library uses. libcurl will use whatever +it thinks fit. +.IP CURL_HTTP_VERSION_1_0 +Enforce HTTP 1.0 requests. +.IP CURL_HTTP_VERSION_1_1 +Enforce HTTP 1.1 requests. +.RE +.IP 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 accurately report +progress, and will simply stop the download when the server ends the +connection. (added in 7.14.1) +.IP CURLOPT_HTTP_CONTENT_DECODING +Pass a long to tell libcurl how to act on content decoding. If set to zero, +content decoding will be disabled. If set to 1 it is enabled. Libcurl has no +default content decoding but requires you to use \fICURLOPT_ENCODING\fP for +that. (added in 7.16.2) +.IP 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) +.SH SMTP OPTIONS +.IP CURLOPT_MAIL_FROM +Pass a pointer to a zero terminated string as parameter. This should be used +to specify the sender's email address when sending SMTP mail with libcurl. + +An originator email address should be specified with angled brackets (<>) +around it, which if not specified, will be added by libcurl from version +7.21.4 onwards. Failing to provide such brackets may cause the server to +reject the email. + +If this parameter is not specified then an empty address will be sent to the +mail server which may or may not cause the email to be rejected. + +(Added in 7.20.0) +.IP 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 \fBstruct +curl_slist\fP structs properly filled in. Use \fIcurl_slist_append(3)\fP to +create the list and \fIcurl_slist_free_all(3)\fP to clean up an entire list. + +Each recipient should be specified within a pair of angled brackets (<>), +however, should you not use an angled bracket as the first character libcurl +will assume you provided a single email address and enclose that address +within brackets for you. + +(Added in 7.20.0) +.IP CURLOPT_MAIL_AUTH +Pass a pointer to a zero terminated string as parameter. This will be used +to specify the authentication address (identity) of a submitted message that +is being relayed to another server. + +This optional parameter allows co-operating agents in a trusted environment to +communicate the authentication of individual messages and should only be used +by the application program, using libcurl, if the application is itself a +mail server acting in such an environment. If the application is operating as +such and the AUTH address is not known or is invalid, then an empty string +should be used for this parameter. + +Unlike CURLOPT_MAIL_FROM and CURLOPT_MAIL_RCPT, the address should not be +specified within a pair of angled brackets (<>). However, if an empty string +is used then a pair of brackets will be sent by libcurl as required by +RFC2554. + +(Added in 7.25.0) +.SH TFTP OPTIONS +.IP CURLOPT_TFTP_BLKSIZE +Specify block size to use for TFTP data transmission. Valid range as per +RFC2348 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) +.SH FTP OPTIONS +.IP 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, 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 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 followed 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: + +.nf + eth0:0 + 192.168.1.2:32000-33000 + curl.se:32123 + [::1]:1234-4567 +.fi + +You disable PORT again and go back to using the passive version by setting +this option to NULL. +.IP 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 \fIcurl_slist_append(3)\fP to append strings (commands) to the +list, and clear the entire list afterwards with +\fIcurl_slist_free_all(3)\fP. Disable this operation again by setting a NULL +to this option. When speaking to a FTP (or SFTP since 7.24.0) server, prefix +the command with an asterisk (*) to make libcurl continue even if the command +fails as by default libcurl will stop at first failure. + +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 +.BR curl (1)) +(SFTP support added in 7.16.3) +.IP 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 \fICURLOPT_QUOTE\fP. Disable this +operation again by setting a NULL to this option. +.IP CURLOPT_PREQUOTE +Pass a pointer to a linked list of FTP commands to pass to the server after +the transfer type is set. The linked list should be a fully valid list of +struct curl_slist structs properly filled in as described for +\fICURLOPT_QUOTE\fP. Disable this operation again by setting a NULL to this +option. Before version 7.16.0, if you also set \fICURLOPT_NOBODY\fP to 1, this +option didn't work. +.IP 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 +subdirectories and symbolic links. + +Setting this option to 1 also implies a directory listing even if the URL +doesn't end with a slash, which otherwise is necessary. + +Do NOT use this option if you also use \fICURLOPT_WILDCARDMATCH\fP as it will +effectively break that feature then. + +(This option was known as CURLOPT_FTPLISTONLY up to 7.16.4) +.IP CURLOPT_APPEND +A parameter set to 1 tells the library to append to the remote file instead of +overwrite it. This is only useful when uploading to an FTP site. + +(This option was known as CURLOPT_FTPAPPEND up to 7.16.4) +.IP 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 downloads (which is enabled by +\fICURLOPT_FTPPORT\fP). 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. +.IP 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. +.IP CURLOPT_FTP_USE_PRET +Pass a long. If the value is 1, it tells curl to send a PRET command before +PASV (and EPSV). Certain FTP servers, mainly drftpd, require this non-standard +command 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) +.IP 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 simultaneous 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 \fICURLFTP_CREATE_DIR\fP and +\fICURLFTP_CREATE_DIR_RETRY\fP enum names for these arguments. + +Before version 7.19.4, libcurl will simply ignore arguments set to 2 and act +as if 1 was selected. +.IP 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 overrides \fICURLOPT_TIMEOUT\fP. It is +recommended that if used in conjunction with \fICURLOPT_TIMEOUT\fP, you set +\fICURLOPT_FTP_RESPONSE_TIMEOUT\fP to a value smaller than +\fICURLOPT_TIMEOUT\fP. (Added in 7.10.8) +.IP 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) +.IP 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 +connects 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. +.IP 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 +\fICURLOPT_USE_SSL\fP). (Added in 7.12.2) +.RS +.IP CURLFTPAUTH_DEFAULT +Allow libcurl to decide. +.IP CURLFTPAUTH_SSL +Try "AUTH SSL" first, and only if that fails try "AUTH TLS". +.IP CURLFTPAUTH_TLS +Try "AUTH TLS" first, and only if that fails try "AUTH SSL". +.RE +.IP CURLOPT_FTP_SSL_CCC +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 communication 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) +.RS +.IP CURLFTPSSL_CCC_NONE +Don't attempt to use CCC. +.IP CURLFTPSSL_CCC_PASSIVE +Do not initiate the shutdown, but wait for the server to do it. Do not send +a reply. +.IP CURLFTPSSL_CCC_ACTIVE +Initiate the shutdown and wait for a reply. +.RE +.IP 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) +.IP 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: +.RS +.IP 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. +.IP 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. +.IP CURLFTPMETHOD_SINGLECWD +libcurl does one CWD with the full target directory 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'. +.RE +(Added in 7.15.1) +.SH RTSP OPTIONS +.IP 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 +initialized. (Added in 7.20.0) +.RS +.IP CURL_RTSPREQ_OPTIONS +Used to retrieve the available methods of the server. The application is +responsible for parsing and obeying the response. \fB(The session ID is not +needed for this method.)\fP (Added in 7.20.0) +.IP CURL_RTSPREQ_DESCRIBE +Used to get the low level description of a stream. The application should note +what formats it understands in the \fI'Accept:'\fP header. Unless set +manually, libcurl will automatically fill in \fI'Accept: +application/sdp'\fP. Time-condition headers will be added to Describe requests +if the \fICURLOPT_TIMECONDITION\fP option is active. \fB(The session ID is not +needed for this method)\fP (Added in 7.20.0) +.IP 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 a HTTP PUT or POST just like +\fICURL_RTSPREQ_SET_PARAMETER\fP (Added in 7.20.0) +.IP 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 +\fICURLOPT_RTSP_TRANSPORT\fP option prior to calling setup. If no session ID +is currently set with \fICURLOPT_RTSP_SESSION_ID\fP, libcurl will extract and +use the session ID in the response to this request. \fB(The session ID is not +needed for this method).\fP (Added in 7.20.0) +.IP CURL_RTSPREQ_PLAY +Send a Play command to the server. Use the \fICURLOPT_RANGE\fP option to +modify the playback time (e.g. 'npt=10-15'). (Added in 7.20.0) +.IP CURL_RTSPREQ_PAUSE +Send a Pause command to the server. Use the \fICURLOPT_RANGE\fP option with a +single value to indicate when the stream should be halted. (e.g. npt='25') +(Added in 7.20.0) +.IP 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 session over +different connections. (Added in 7.20.0) +.IP CURL_RTSPREQ_GET_PARAMETER +Retrieve a parameter from the server. By default, libcurl will automatically +include a \fIContent-Type: text/parameters\fP header on all non-empty requests +unless a custom one is set. GET_PARAMETER acts just like a HTTP PUT or POST +(see \fICURL_RTSPREQ_SET_PARAMETER\fP). +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) +.IP CURL_RTSPREQ_SET_PARAMETER +Set a parameter on the server. By default, libcurl will automatically include +a \fIContent-Type: text/parameters\fP header unless a custom one is set. The +interaction with SET_PARAMTER is much like a HTTP PUT or POST. An application +may either use \fICURLOPT_UPLOAD\fP with \fICURLOPT_READDATA\fP like a HTTP +PUT, or it may use \fICURLOPT_POSTFIELDS\fP like a HTTP POST. No chunked +transfers are allowed, so the application must set the +\fICURLOPT_INFILESIZE\fP in the former and \fICURLOPT_POSTFIELDSIZE\fP in the +latter. Also, there is no use of multi-part POSTs within RTSP. (Added in +7.20.0) +.IP CURL_RTSPREQ_RECORD +Used to tell the server to record a session. Use the \fICURLOPT_RANGE\fP +option to modify the record time. (Added in 7.20.0) +.IP 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) +.RE +.IP 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 to any non-NULL value, libcurl will return \fICURLE_RTSP_SESSION_ERROR\fP +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) +.IP CURLOPT_RTSP_STREAM_URI +Set the stream URI to operate on by passing a char * . For example, a single +session may be controlling \fIrtsp://foo/twister/audio\fP and +\fIrtsp://foo/twister/video\fP and the application can switch to the +appropriate stream using this option. If unset, libcurl will default to +operating on generic server options by passing '*' in the place of the RTSP +Stream URI. This option is distinct from \fICURLOPT_URL\fP. When working with +RTSP, the \fICURLOPT_STREAM_URI\fP indicates what URL to send to the server in +the request header while the \fICURLOPT_URL\fP indicates where to make the +connection to. (e.g. the \fICURLOPT_URL\fP for the above examples might be +set to \fIrtsp://foo/twister\fP (Added in 7.20.0) +.IP 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 application must set a +Transport: header before issuing a SETUP request. (Added in 7.20.0) +.IP CURLOPT_RTSP_HEADER +This option is simply an alias for \fICURLOPT_HTTP_HEADER\fP. Use this to +replace the standard headers that RTSP and HTTP share. It is also valid to use +the shortcuts such as \fICURLOPT_USERAGENT\fP. (Added in 7.20.0) +.IP 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) +.IP 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 +unimplemented. (Added in 7.20.0) +.SH PROTOCOL OPTIONS +.IP 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 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. + +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 +simply sets the mode to ASCII and performs a standard transfer. +.IP 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 a HTTP proxy, by +appending ;type=a or ;type=i to the URL. Without this setting, or it being set +to 0 (zero, the default), \fICURLOPT_TRANSFERTEXT\fP has no effect when doing +FTP via a proxy. Beware that not all proxies support this feature. (Added in +7.18.0) +.IP CURLOPT_CRLF +Pass a long. If the value is set to 1 (one), libcurl converts Unix newlines to +CRLF newlines on transfers. Disable this option again by setting the value to +0 (zero). +.IP 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 +\fI"X-Y,N-M"\fP. Using this kind of multiple intervals will cause the HTTP +server to send the response document in pieces (using standard MIME separation +techniques). For RTSP, the formatting of a range should follow RFC2326 +Section 12.29. For RTSP, byte ranges are \fBnot\fP 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. +.IP 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). + +When doing uploads with FTP, the resume position is where in the local/source +file libcurl should try to resume the upload from and it will then append the +source file to the remote target file. +.IP 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) +.IP CURLOPT_CUSTOMREQUEST +Pass a pointer to a zero terminated string as parameter. It can be used to +specify the request instead of GET or HEAD when performing HTTP based +requests, instead of LIST and NLST when performing FTP directory listings and +instead of LIST and RETR when issuing POP3 based commands. This is +particularly useful, for example, for performing a HTTP DELETE request or a +POP3 DELE command. + +Please don't perform this at will, on HTTP based requests, by making sure +your server supports the command you are sending first. + +When you change the request method by setting \fBCURLOPT_CUSTOMREQUEST\fP 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: + +With the HTTP protocol when you tell libcurl to do a HEAD request, but then +specify a GET though a custom request libcurl will still act as if it sent a +HEAD. To switch to a proper HEAD use \fICURLOPT_NOBODY\fP, to switch to a +proper POST use \fICURLOPT_POST\fP or \fICURLOPT_POSTFIELDS\fP and to switch +to a proper GET use CURLOPT_HTTPGET. + +With the POP3 protocol when you tell libcurl to use a custom request it will +behave like a LIST or RETR command was sent where it expects data to be +returned by the server. As such \fICURLOPT_NOBODY\fP should be used when +specifying commands such as DELE and NOOP for example. + +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 \fICURLOPT_POST\fP and +\fICURLOPT_POSTFIELDS\fP to set POST data. Use \fICURLOPT_HTTPHEADER\fP to +replace or extend the set of headers sent by libcurl. Use +\fICURLOPT_HTTP_VERSION\fP to change HTTP version. + +(Support for POP3 added in 7.26.0) +.IP 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 +\fIcurl_easy_getinfo(3)\fP function with the \fICURLINFO_FILETIME\fP argument +can be used after a transfer to extract the received time (if any). +.IP CURLOPT_NOBODY +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 \fICURLOPT_HTTPGET\fP. Change +request to POST with \fICURLOPT_POST\fP etc. +.IP 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 \fICURLOPT_INFILESIZE_LARGE\fP. + +For uploading using SCP, this option or \fICURLOPT_INFILESIZE_LARGE\fP is +mandatory. + +When sending emails using SMTP, this command can be used to specify the +optional SIZE parameter for the MAIL FROM command. (Added in 7.23.0) + +This option does not limit how much data libcurl will actually send, as that +is controlled entirely by what the read callback returns. +.IP 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 \fICURLOPT_INFILESIZE\fP 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. +.IP CURLOPT_UPLOAD +A parameter set to 1 tells the library to prepare for an upload. The +\fICURLOPT_READDATA\fP and \fICURLOPT_INFILESIZE\fP or +\fICURLOPT_INFILESIZE_LARGE\fP options are also interesting 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 \fICURLOPT_HTTPHEADER\fP 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" with +\fICURLOPT_HTTPHEADER\fP. With HTTP 1.0 or without chunked transfer, you must +specify the size. +.IP 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. +.IP CURLOPT_MAXFILESIZE_LARGE +Pass a curl_off_t 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 \fICURLE_FILESIZE_EXCEEDED\fP 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. +.IP CURLOPT_TIMECONDITION +Pass a long as parameter. This defines how the \fICURLOPT_TIMEVALUE\fP time +value is treated. You can set this parameter to \fICURL_TIMECOND_IFMODSINCE\fP +or \fICURL_TIMECOND_IFUNMODSINCE\fP. This feature applies to HTTP, FTP, RTSP, +and FILE. + +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. \fIcurl_easy_getinfo(3)\fP with the +\fICURLINFO_CONDITION_UNMET\fP option can be used after a transfer to learn if +a zero-byte successful "transfer" was due to this condition not matching. +.IP 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 +\fICURLOPT_TIMECONDITION\fP. +.SH CONNECTION OPTIONS +.IP 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. + +In unix-like systems, this might cause signals to be used unless +\fICURLOPT_NOSIGNAL\fP is set. + +Default timeout is 0 (zero) which means it never times out. +.IP CURLOPT_TIMEOUT_MS +Like \fICURLOPT_TIMEOUT\fP 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) +.IP 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 \fICURLOPT_LOW_SPEED_TIME\fP seconds +for the library to consider it too slow and abort. +.IP CURLOPT_LOW_SPEED_TIME +Pass a long as parameter. It contains the time in seconds that the transfer +should be below the \fICURLOPT_LOW_SPEED_LIMIT\fP for the library to consider +it too slow and abort. +.IP 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 parameter value. +Defaults to unlimited speed. (Added in 7.15.5) +.IP 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 parameter +value. Defaults to unlimited speed. (Added in 7.15.5) +.IP CURLOPT_MAXCONNECTS +Pass a long. The set number will be the persistent connection 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. + +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 \fIcurl_multi_setopt(3)\fP and the +\fICURLMOPT_MAXCONNECTS\fP option. +.IP CURLOPT_CLOSEPOLICY +(Obsolete) This option does nothing. +.IP 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 +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). +.IP CURLOPT_FORBID_REUSE +Pass a long. Set to 1 to make the next transfer explicitly 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). +.IP 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 switch to the +default built-in connection timeout - 300 seconds. See also the +\fICURLOPT_TIMEOUT\fP option. + +In unix-like systems, this might cause signals to be used unless +\fICURLOPT_NOSIGNAL\fP is set. +.IP CURLOPT_CONNECTTIMEOUT_MS +Like \fICURLOPT_CONNECTTIMEOUT\fP but takes the number of milliseconds +instead. If libcurl is built to use the standard system name resolver, +that portion of the connect will still use full-second resolution for +timeouts with a minimum timeout allowed of one second. +(Added in 7.16.2) +.IP 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: +.RS +.IP CURL_IPRESOLVE_WHATEVER +Default, resolves addresses to all IP versions that your system allows. +.IP CURL_IPRESOLVE_V4 +Resolve to IPv4 addresses. +.IP CURL_IPRESOLVE_V6 +Resolve to IPv6 addresses. +.RE +.IP CURLOPT_CONNECT_ONLY +Pass a long. If the parameter equals 1, it tells the library to perform all +the required proxy authentication and connection setup, but no data transfer. +This option is implemented for HTTP, SMTP and POP3. + +The option can be used to simply test a connection to a server, but is more +useful when used with the \fICURLINFO_LASTSOCKET\fP option to +\fIcurl_easy_getinfo(3)\fP as 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) +.IP CURLOPT_USE_SSL +Pass a long using one of the values from below, to make libcurl use your +desired level of SSL for the transfer. (Added in 7.11.0) + +This is for enabling SSL/TLS when you use FTP, SMTP, POP3, IMAP etc. + +(This option was known as CURLOPT_FTP_SSL up to 7.16.4, and the constants +were known as CURLFTPSSL_*) +.RS +.IP CURLUSESSL_NONE +Don't attempt to use SSL. +.IP CURLUSESSL_TRY +Try using SSL, proceed as normal otherwise. +.IP CURLUSESSL_CONTROL +Require SSL for the control connection or fail with \fICURLE_USE_SSL_FAILED\fP. +.IP CURLUSESSL_ALL +Require SSL for all communication or fail with \fICURLE_USE_SSL_FAILED\fP. +.RE +.IP CURLOPT_RESOLVE +Pass a pointer to a linked list of strings with host name resolve information +to use for requests with this handle. The linked list should be a fully valid +list of \fBstruct curl_slist\fP structs properly filled in. Use +\fIcurl_slist_append(3)\fP to create the list and \fIcurl_slist_free_all(3)\fP +to clean up an entire list. + +Each single name resolve string should be written using the format +HOST:PORT:ADDRESS where HOST is the name libcurl will try to resolve, PORT is +the port number of the service where libcurl wants to connect to the HOST and +ADDRESS is the numerical IP address. If libcurl is built to support IPv6, +ADDRESS can of course be either IPv4 or IPv6 style addressing. + +This option effectively pre-populates the DNS cache with entries for the +host+port pair so redirects and everything that operations against the +HOST+PORT will instead use your provided ADDRESS. + +You can remove names from the DNS cache again, to stop providing these fake +resolves, by including a string in the linked list that uses the format +\&"-HOST:PORT". The host name must be prefixed with a dash, and the host name +and port number must exactly match what was already added previously. + +(Added in 7.21.3) +.IP CURLOPT_DNS_SERVERS +Set the list of DNS servers to be used instead of the system default. +The format of the dns servers option is: + +host[:port][,host[:port]]... + +For example: + +192.168.1.100,192.168.1.101,3.4.5.6 + +This option requires that libcurl was built with a resolver backend that +supports this operation. The c-ares backend is the only such one. + +(Added in 7.24.0) +.IP CURLOPT_ACCEPTTIMEOUT_MS +Pass a long telling libcurl the maximum number of milliseconds to wait for a +server to connect back to libcurl when an active FTP connection is used. If no +timeout is set, the internal default of 60000 will be used. (Added in 7.24.0) +.SH SSL and SECURITY OPTIONS +.IP 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 \fICURLOPT_SSLCERTTYPE\fP. + +With NSS this can also be the nickname of the certificate you wish to +authenticate with. If you want to use a file from the current directory, please +precede it with "./" prefix, in order to avoid confusion with a nickname. +.IP 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) +.IP 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 \fICURLOPT_SSLKEYTYPE\fP. +.IP 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". + +The format "ENG" enables you to load the private key from a crypto engine. In +this case \fICURLOPT_SSLKEY\fP is used as an identifier passed to the +engine. You have to set the crypto engine with \fICURLOPT_SSLENGINE\fP. +\&"DER" format key file currently does not work because of a bug in OpenSSL. +.IP CURLOPT_KEYPASSWD +Pass a pointer to a zero terminated string as parameter. It will be used as +the password required to use the \fICURLOPT_SSLKEY\fP or +\fICURLOPT_SSH_PRIVATE_KEYFILE\fP 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) +.IP CURLOPT_SSLENGINE +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. + +If the crypto device cannot be loaded, \fICURLE_SSL_ENGINE_NOTFOUND\fP is +returned. +.IP CURLOPT_SSLENGINE_DEFAULT +Sets the actual crypto engine as the default for (asymmetric) crypto +operations. + +If the crypto device cannot be set, \fICURLE_SSL_ENGINE_SETFAILED\fP is +returned. + +Even though this option doesn't need any parameter, in some configurations +\fIcurl_easy_setopt\fP might be defined as a macro taking exactly three +arguments. Therefore, it's recommended to pass 1 as parameter to this option. +.IP CURLOPT_SSLVERSION +Pass a long as parameter to control what version of SSL/TLS to attempt to use. +The available options are: +.RS +.IP CURL_SSLVERSION_DEFAULT +The default action. This will attempt to figure out the remote SSL protocol +version, i.e. either SSLv3 or TLSv1 (but not SSLv2, which became disabled +by default with 7.18.1). +.IP CURL_SSLVERSION_TLSv1 +Force TLSv1 +.IP CURL_SSLVERSION_SSLv2 +Force SSLv2 +.IP CURL_SSLVERSION_SSLv3 +Force SSLv3 +.RE +.IP CURLOPT_SSL_VERIFYPEER +Pass a long as parameter. By default, curl assumes a value of 1. + +This option determines whether curl verifies the authenticity of the peer's +certificate. A value of 1 means curl verifies; 0 (zero) means it doesn't. + +When negotiating a 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 signatures, rooted in certification authority +(CA) certificates you supply. curl uses a default bundle of CA certificates +(the path for that is determined at build time) and you can specify alternate +certificates with the \fICURLOPT_CAINFO\fP option or the \fICURLOPT_CAPATH\fP +option. + +When \fICURLOPT_SSL_VERIFYPEER\fP is nonzero, and the verification fails to +prove that the certificate is authentic, the connection fails. When the +option is zero, the peer certificate verification 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 +\fICURLOPT_SSL_VERIFYHOST\fP to control that. The check that the host name in +the certificate is valid for the host name you're connecting to is done +independently of the \fICURLOPT_SSL_VERIFYPEER\fP option. +.IP 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 \fICURLOPT_SSL_VERIFYPEER\fP option. If +\fICURLOPT_SSL_VERIFYPEER\fP is zero, \fICURLOPT_CAINFO\fP 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 established at build time. + +If curl is built against the NSS SSL library, the NSS PEM PKCS#11 module +(libnsspem.so) needs to be available for this option to work properly. +.IP 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 certificate 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 +certificate is from a specific branch of the tree. + +This option makes sense only when used in combination with the +\fICURLOPT_SSL_VERIFYPEER\fP 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 (\fICURLOPT_SSL_VERIFYPEER\fP has +to be set too for the check to fail). (Added in 7.19.0) +.IP CURLOPT_CAPATH +Pass a char * to a zero terminated string naming a directory holding multiple +CA certificates to verify the peer with. If libcurl is built against OpenSSL, +the certificate directory must be prepared using the openssl c_rehash utility. +This makes sense only when used in combination with the +\fICURLOPT_SSL_VERIFYPEER\fP option. If \fICURLOPT_SSL_VERIFYPEER\fP is zero, +\fICURLOPT_CAPATH\fP need not even indicate an accessible path. The +\fICURLOPT_CAPATH\fP 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. NSS-powered libcurl provides the option only +for backward compatibility. +.IP 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 if +a CRL file is passed. + +This option makes sense only when used in combination with the +\fICURLOPT_SSL_VERIFYPEER\fP 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 revocation information found in +the CRL does not trigger this specific error. (Added in 7.19.0) +.IP 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 \fICURLOPT_SSL_VERIFYHOST\fP 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, libcurl will return a failure. It was previously (in +7.28.0 and earlier) a debug option of some sorts, but it is no longer +supported due to frequently leading to programmer mistakes. + +When the value is 0, the connection succeeds regardless of the names in the +certificate. + +The default value for this option is 2. + +This option controls checking the server's certificate's claimed identity. +The server could be lying. To control lying, see +\fICURLOPT_SSL_VERIFYPEER\fP. If libcurl is built against NSS and +\fICURLOPT_SSL_VERIFYPEER\fP is zero, \fICURLOPT_SSL_VERIFYHOST\fP +is ignored. + +.IP 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 +\fIcurl_easy_getinfo(3)\fP and its option \fICURLINFO_CERTINFO\fP. (Added in +7.19.1) +.IP 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. +.IP 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. +.IP 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 syntactically 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. + +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: +\fIhttp://www.openssl.org/docs/apps/ciphers.html\fP + +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: +\fIhttp://git.fedorahosted.org/cgit/mod_nss.git/plain/docs/mod_nss.html#Directives\fP + +.IP 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 implementations in the wild that may +require you to disable this in order for you to succeed. (Added in 7.16.0) +.IP CURLOPT_SSL_OPTIONS +Pass a long with a bitmask to tell libcurl about specific SSL behaviors. + +CURLSSLOPT_ALLOW_BEAST is the only supported bit and by setting this the user +will tell libcurl to not attempt to use any workarounds for a security flaw +in the SSL3 and TLS1.0 protocols. If this option isn't used or this bit is +set to 0, the SSL layer libcurl uses may use a work-around for this flaw +although it might cause interoperability problems with some (older) SSL +implementations. WARNING: avoiding this work-around loosens the security, and +by setting this option to 1 you ask for exactly that. (Added in 7.25.0) +.IP CURLOPT_KRBLEVEL +Pass a char * as parameter. Set the kerberos security level for FTP; this also +enables kerberos 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 kerberos +support for FTP. + +(This option was known as CURLOPT_KRB4LEVEL up to 7.16.3) +.IP CURLOPT_GSSAPI_DELEGATION +Set the parameter to CURLGSSAPI_DELEGATION_FLAG to allow unconditional GSSAPI +credential delegation. The delegation is disabled by default since 7.21.7. +Set the parameter to CURLGSSAPI_DELEGATION_POLICY_FLAG to delegate only if +the OK-AS-DELEGATE flag is set in the service ticket in case this feature is +supported by the GSSAPI implementation and the definition of +GSS_C_DELEG_POLICY_FLAG was available at compile-time. +(Added in 7.22.0) +.SH SSH OPTIONS +.IP 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 and CURLSSH_AUTH_AGENT. Set CURLSSH_AUTH_ANY to let +libcurl pick a suitable one. Currently CURLSSH_AUTH_HOST has no effect. (Added +in 7.16.1) If CURLSSH_AUTH_AGENT is used, libcurl attempts to connect to +ssh-agent or pageant and let the agent attempt the authentication. (Added in +7.28.0) +.IP CURLOPT_SSH_HOST_PUBLIC_KEY_MD5 +Pass a char * pointing to a string containing 32 hexadecimal 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) +.IP CURLOPT_SSH_PUBLIC_KEYFILE +Pass a char * pointing to a file name for your public key. If not used, +libcurl defaults to \fB$HOME/.ssh/id_dsa.pub\fP if the HOME environment +variable is set, and just "id_dsa.pub" in the current directory if HOME is not +set. (Added in 7.16.1) +If an empty string is passed, libcurl will pass no public key to libssh2 +which then tries to compute it from the private key, this is known to work +when libssh2 1.4.0+ is linked against OpenSSL. (Added in 7.26.0) +.IP CURLOPT_SSH_PRIVATE_KEYFILE +Pass a char * pointing to a file name for your private key. If not used, +libcurl defaults to \fB$HOME/.ssh/id_dsa\fP if the HOME environment variable +is set, and just "id_dsa" in the current directory if HOME is not set. If the +file is password-protected, set the password with +\fICURLOPT_KEYPASSWD\fP. (Added in 7.16.1) +.IP 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, libcurl will only +accept connections with hosts that are known and present in that file, with a +matching public key. Use \fICURLOPT_SSH_KEYFUNCTION\fP to alter the default +behavior on host and key (mis)matching. (Added in 7.19.6) +.IP 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. The callback will only be called if +\fICURLOPT_SSH_KNOWNHOSTS\fP is also set. + +The curl_sshkeycallback function gets passed the CURL handle, the key from the +known_hosts file, the key from the remote site, info from libcurl on the +matching status and a custom pointer (set with \fICURLOPT_SSH_KEYDATA\fP). It +MUST return one of the following return codes to tell libcurl how to act: +.RS +.IP 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. +.IP 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. +.IP CURLKHSTAT_REJECT +The host+key is rejected. libcurl will deny the connection to continue and it +will be closed. +.IP 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. +.RE + (Added in 7.19.6) +.IP CURLOPT_SSH_KEYDATA +Pass a void * as parameter. This pointer will be passed along verbatim to the +callback set with \fICURLOPT_SSH_KEYFUNCTION\fP. (Added in 7.19.6) +.SH OTHER OPTIONS +.IP 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 +\fIcurl_easy_getinfo(3)\fP with the CURLINFO_PRIVATE option. libcurl itself +does nothing with this data. (Added in 7.10.3) +.IP CURLOPT_SHARE +Pass a share handle as a parameter. The share handle must have been created by +a previous call to \fIcurl_share_init(3)\fP. Setting this option, will make +this 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 \fBMUST\fP use the +locking methods in the share handle. See \fIcurl_share_setopt(3)\fP 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. +.IP 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 +\fI0644\fP, but any valid value can be used. The only protocols that can use +this are \fIsftp://\fP, \fIscp://\fP, and \fIfile://\fP. (Added in 7.16.4) +.IP 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 \fI0755\fP, but any valid value can be used. The only protocols that +can use this are \fIsftp://\fP, \fIscp://\fP, and \fIfile://\fP. +(Added in 7.16.4) +.SH TELNET OPTIONS +.IP CURLOPT_TELNETOPTIONS +Provide a pointer to a curl_slist with variables to pass to the telnet +negotiations. The variables should be in the format <option=value>. libcurl +supports the options 'TTYPE', 'XDISPLOC' and 'NEW_ENV'. See the TELNET +standard for details. +.SH RETURN VALUE +CURLE_OK (zero) means that the option was set properly, non-zero means an +error occurred as \fI<curl/curl.h>\fP defines. See the \fIlibcurl-errors(3)\fP +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 \fICURLE_FAILED_INIT\fP. +.SH "SEE ALSO" +.BR curl_easy_init "(3), " curl_easy_cleanup "(3), " curl_easy_reset "(3)" |