1curl_easy_setopt(3) libcurl Manual curl_easy_setopt(3)
2
6 curl_easy_setopt - set options for a curl easy handle
7
9 #include <curl/curl.h>
10 CURLcode curl_easy_setopt(CURL *handle, CURLoption option, parameter);
12
14 curl_easy_setopt() is used to tell libcurl how to behave. By using the
15 appropriate options to curl_easy_setopt, you can change libcurl's
16 behavior. All options are set with the option followed by a parameter.
17 That parameter can be a long, a function pointer, an object pointer or
18 a curl_off_t, depending on what the specific option expects. Read this
19 manual carefully as bad input values may cause libcurl to behave badly!
20 You can only set one option in each function call. A typical applica‐
21 tion uses many curl_easy_setopt() calls in the setup phase.
22 Options set with this function call are valid for all forthcoming
24 transfers performed using this handle. The options are not in any way
25 reset between transfers, so if you want subsequent transfers with dif‐
26 ferent options, you must change them between the transfers. You can
27 optionally reset all options back to internal default with
28 curl_easy_reset(3).
29 Strings passed to libcurl as 'char *' arguments, will not be copied by
31 the library. Instead you should keep them available until libcurl no
32 longer needs them. Failing to do so will cause very odd behavior or
33 even crashes. libcurl will need them until you call
34 curl_easy_cleanup(3) or you set the same option again to use a differ‐
35 ent pointer.
36 The handle is the return code from a curl_easy_init(3) or
38 curl_easy_duphandle(3) call.
39
41 CURLOPT_VERBOSE
42 Set the parameter to non-zero to get the library to display a
43 lot of verbose information about its operations. Very useful for
44 libcurl and/or protocol debugging and understanding. The verbose
45 information will be sent to stderr, or the stream set with CUR‐
46 LOPT_STDERR.
47 You hardly ever want this set in production use, you will almost
49 always want this when you debug/report problems. Another neat
50 option for debugging is the CURLOPT_DEBUGFUNCTION.
51 CURLOPT_HEADER
53 A non-zero parameter tells the library to include the header in
54 the body output. This is only relevant for protocols that actu‐
55 ally have headers preceding the data (like HTTP).
56 CURLOPT_NOPROGRESS
58 A non-zero parameter tells the library to shut off the built-in
59 progress meter completely.
60 Future versions of libcurl is likely to not have any built-in
62 progress meter at all.
63 CURLOPT_NOSIGNAL
65 Pass a long. If it is non-zero, libcurl will not use any func‐
66 tions that install signal handlers or any functions that cause
67 signals to be sent to the process. This option is mainly here to
68 allow multi-threaded unix applications to still set/use all
69 timeout options etc, without risking getting signals. (Added in
70 7.10)
71 Consider building libcurl with ares support to enable asynchro‐
73 nous DNS lookups. It enables nice timeouts for name resolves
74 without signals.
75
77 CURLOPT_WRITEFUNCTION
78 Function pointer that should match the following prototype:
79 size_t function( void *ptr, size_t size, size_t nmemb, void
80 *stream); This function gets called by libcurl as soon as there
81 is data received that needs to be saved. The size of the data
82 pointed to by ptr is size multiplied with nmemb, it will not be
83 zero terminated. Return the number of bytes actually taken care
84 of. If that amount differs from the amount passed to your func‐
85 tion, it'll signal an error to the library and it will abort the
86 transfer and return CURLE_WRITE_ERROR.
87 This function may be called with zero bytes data if the trans‐
89 fered file is empty.
90 Set this option to NULL to get the internal default function.
92 The internal default function will write the data to the FILE *
93 given with CURLOPT_WRITEDATA.
94 Set the stream argument with the CURLOPT_WRITEDATA option.
96 The callback function will be passed as much data as possible in
98 all invokes, but you cannot possibly make any assumptions. It
99 may be one byte, it may be thousands. The maximum amount of data
100 that can be passed to the write callback is defined in the
101 curl.h header file: CURL_MAX_WRITE_SIZE.
102 CURLOPT_WRITEDATA
104 Data pointer to pass to the file write function. If you use the
105 CURLOPT_WRITEFUNCTION option, this is the pointer you'll get as
106 input. If you don't use a callback, you must pass a 'FILE *' as
107 libcurl will pass this to fwrite() when writing data.
108 The internal CURLOPT_WRITEFUNCTION will write the data to the
110 FILE * given with this option, or to stdout if this option
111 hasn't been set.
112 If you're using libcurl as a win32 DLL, you MUST use the CUR‐
114 LOPT_WRITEFUNCTION if you set this option or you will experience
115 crashes.
116 This option is also known with the older name CURLOPT_FILE, the
118 name CURLOPT_WRITEDATA was introduced in 7.9.7.
119 CURLOPT_READFUNCTION
121 Function pointer that should match the following prototype:
122 size_t function( void *ptr, size_t size, size_t nmemb, void
123 *stream); This function gets called by libcurl as soon as it
124 needs to read data in order to send it to the peer. The data
125 area pointed at by the pointer ptr may be filled with at most
126 size multiplied with nmemb number of bytes. Your function must
127 return the actual number of bytes that you stored in that memory
128 area. Returning 0 will signal end-of-file to the library and
129 cause it to stop the current transfer.
130 If you stop the current transfer by returning 0 "pre-maturely"
132 (i.e before the server expected it, like when you've told you
133 will upload N bytes and you upload less than N bytes), you may
134 experience that the server "hangs" waiting for the rest of the
135 data that won't come.
136 The read callback may return CURL_READFUNC_ABORT to stop the
138 current operation immediately, resulting in a
139 CURLE_ABORTED_BY_CALLBACK error code from the transfer (Added in
140 7.12.1)
141 If you set the callback pointer to NULL, or doesn't set it at
143 all, the default internal read function will be used. It is sim‐
144 ply doing an fread() on the FILE * stream set with CURLOPT_READ‐
145 DATA.
146 CURLOPT_READDATA
148 Data pointer to pass to the file read function. If you use the
149 CURLOPT_READFUNCTION option, this is the pointer you'll get as
150 input. If you don't specify a read callback but instead rely on
151 the default internal read function, this data must be a valid
152 readable FILE *.
153 If you're using libcurl as a win32 DLL, you MUST use a CUR‐
155 LOPT_READFUNCTION if you set this option.
156 This option is also known with the older name CURLOPT_INFILE,
158 the name CURLOPT_READDATA was introduced in 7.9.7.
159 CURLOPT_IOCTLFUNCTION
161 Function pointer that should match the curl_ioctl_callback pro‐
162 totype found in <curl/curl.h>. This function gets called by
163 libcurl when something special I/O-related needs to be done that
164 the library can't do by itself. For now, rewinding the read data
165 stream is the only action it can request. The rewinding of the
166 read data stream may be necessary when doing a HTTP PUT or POST
167 with a multi-pass authentication method. (Option added in
168 7.12.3)
169 CURLOPT_IOCTLDATA
171 Pass a pointer that will be untouched by libcurl and passed as
172 the 3rd argument in the ioctl callback set with CURLOPT_IOCTL‐
173 FUNCTION. (Option added in 7.12.3)
174 CURLOPT_SOCKOPTFUNCTION
176 Function pointer that should match the curl_sockopt_callback
177 prototype found in <curl/curl.h>. This function gets called by
178 libcurl after the socket() call but before the connect() call.
179 The callback's purpose argument identifies the exact purpose for
180 this particular socket, and currently only one value is sup‐
181 ported: CURLSOCKTYPE_IPCXN for the primary connection (meaning
182 the control connection in the FTP case). Future versions of
183 libcurl may support more purposes. It passes the newly created
184 socket descriptor so additional setsockopt() calls can be done
185 at the user's discretion. A non-zero return code from the call‐
186 back function will signal an unrecoverable error to the library
187 and it will close the socket and return CURLE_COULDNT_CONNECT.
188 (Option added in 7.15.6.)
189 CURLOPT_SOCKOPTDATA
191 Pass a pointer that will be untouched by libcurl and passed as
192 the first argument in the sockopt callback set with CUR‐
193 LOPT_SOCKOPTFUNCTION. (Option added in 7.15.6.)
194 CURLOPT_PROGRESSFUNCTION
196 Function pointer that should match the curl_progress_callback
197 prototype found in <curl/curl.h>. This function gets called by
198 libcurl instead of its internal equivalent with a frequent
199 interval during operation (roughly once per second) no matter if
200 data is being transfered or not. Unknown/unused argument values
201 passed to the callback will be set to zero (like if you only
202 download data, the upload size will remain 0). Returning a non-
203 zero value from this callback will cause libcurl to abort the
204 transfer and return CURLE_ABORTED_BY_CALLBACK.
205 If you transfer data with the multi interface, this function
207 will not be called during periods of idleness unless you call
208 the appropriate libcurl function that performs transfers. Usage
209 of the CURLOPT_PROGRESSFUNCTION callback is not recommended when
210 using the multi interface.
211 CURLOPT_NOPROGRESS must be set to FALSE to make this function
213 actually get called.
214 CURLOPT_PROGRESSDATA
216 Pass a pointer that will be untouched by libcurl and passed as
217 the first argument in the progress callback set with CUR‐
218 LOPT_PROGRESSFUNCTION.
219 CURLOPT_HEADERFUNCTION
221 Function pointer that should match the following prototype:
222 size_t function( void *ptr, size_t size, size_t nmemb, void
223 *stream);. This function gets called by libcurl as soon as it
224 has received header data. The header callback will be called
225 once for each header and only complete header lines are passed
226 on to the callback. Parsing headers should be easy enough using
227 this. The size of the data pointed to by ptr is size multiplied
228 with nmemb. Do not assume that the header line is zero termi‐
229 nated! The pointer named stream is the one you set with the CUR‐
230 LOPT_WRITEHEADER option. The callback function must return the
231 number of bytes actually taken care of, or return -1 to signal
232 error to the library (it will cause it to abort the transfer
233 with a CURLE_WRITE_ERROR return code).
234 Since 7.14.1: When a server sends a chunked encoded transfer, it
236 may contain a trailer. That trailer is identical to a HTTP
237 header and if such a trailer is received it is passed to the
238 application using this callback as well. There are several ways
239 to detect it being a trailer and not an ordinary header: 1) it
240 comes after the response-body. 2) it comes after the final
241 header line (CR LF) 3) a Trailer: header among the response-
242 headers mention what header to expect in the trailer.
243 CURLOPT_WRITEHEADER
245 (This option is also known as CURLOPT_HEADERDATA) Pass a pointer
246 to be used to write the header part of the received data to. If
247 you don't use your own callback to take care of the writing,
248 this must be a valid FILE *. See also the CURLOPT_HEADERFUNCTION
249 option above on how to set a custom get-all-headers callback.
250 CURLOPT_DEBUGFUNCTION
252 Function pointer that should match the following prototype: int
253 curl_debug_callback (CURL *, curl_infotype, char *, size_t, void
254 *); CURLOPT_DEBUGFUNCTION replaces the standard debug function
255 used when CURLOPT_VERBOSE is in effect. This callback receives
256 debug information, as specified with the curl_infotype argument.
257 This function must return 0. The data pointed to by the char *
258 passed to this function WILL NOT be zero terminated, but will be
259 exactly of the size as told by the size_t argument.
260 Available curl_infotype values:
262 CURLINFO_TEXT
264 The data is informational text.
265 CURLINFO_HEADER_IN
267 The data is header (or header-like) data received from
268 the peer.
269 CURLINFO_HEADER_OUT
271 The data is header (or header-like) data sent to the
272 peer.
273 CURLINFO_DATA_IN
275 The data is protocol data received from the peer.
276 CURLINFO_DATA_OUT
278 The data is protocol data sent to the peer.
279 CURLOPT_DEBUGDATA
281 Pass a pointer to whatever you want passed in to your CUR‐
282 LOPT_DEBUGFUNCTION in the last void * argument. This pointer is
283 not used by libcurl, it is only passed to the callback.
284 CURLOPT_SSL_CTX_FUNCTION
286 Function pointer that should match the following prototype:
287 CURLcode sslctxfun(CURL *curl, void *sslctx, void *parm); This
288 function gets called by libcurl just before the initialization
289 of an SSL connection after having processed all other SSL
290 related options to give a last chance to an application to mod‐
291 ify the behaviour of openssl's ssl initialization. The sslctx
292 parameter is actually a pointer to an openssl SSL_CTX. If an
293 error is returned no attempt to establish a connection is made
294 and the perform operation will return the error code from this
295 callback function. Set the parm argument with the CUR‐
296 LOPT_SSL_CTX_DATA option. This option was introduced in 7.11.0.
297 This function will get called on all new connections made to a
299 server, during the SSL negotiation. The SSL_CTX pointer will be
300 a new one every time.
301 To use this properly, a non-trivial amount of knowledge of the
303 openssl libraries is necessary. Using this function allows for
304 example to use openssl callbacks to add additional validation
305 code for certificates, and even to change the actual URI of an
306 HTTPS request (example used in the lib509 test case). See also
307 the example section for a replacement of the key, certificate
308 and trust file settings.
309 CURLOPT_SSL_CTX_DATA
311 Data pointer to pass to the ssl context callback set by the
312 option CURLOPT_SSL_CTX_FUNCTION, this is the pointer you'll get
313 as third parameter, otherwise NULL. (Added in 7.11.0)
314 CURLOPT_CONV_TO_NETWORK_FUNCTION
316 CURLOPT_CONV_FROM_NETWORK_FUNCTION
318 CURLOPT_CONV_FROM_UTF8_FUNCTION
320 Function pointers that should match the following prototype:
321 CURLcode function(char *ptr, size_t length);
322 These three options apply to non-ASCII platforms only. They are
324 available only if CURL_DOES_CONVERSIONS was defined when libcurl
325 was built. When this is the case, curl_version_info(3) will
326 return the CURL_VERSION_CONV feature bit set.
327 The data to be converted is in a buffer pointed to by the ptr
329 parameter. The amount of data to convert is indicated by the
330 length parameter. The converted data overlays the input data in
331 the buffer pointed to by the ptr parameter. CURLE_OK should be
332 returned upon successful conversion. A CURLcode return value
333 defined by curl.h, such as CURLE_CONV_FAILED, should be returned
334 if an error was encountered.
335 CURLOPT_CONV_TO_NETWORK_FUNCTION and CURLOPT_CONV_FROM_NET‐
337 WORK_FUNCTION convert between the host encoding and the network
338 encoding. They are used when commands or ASCII data are
339 sent/received over the network.
340 CURLOPT_CONV_FROM_UTF8_FUNCTION is called to convert from UTF8
342 into the host encoding. It is required only for SSL processing.
343 If you set a callback pointer to NULL, or don't set it at all,
345 the built-in libcurl iconv functions will be used. If
346 HAVE_ICONV was not defined when libcurl was built, and no call‐
347 back has been established, conversion will return the
348 CURLE_CONV_REQD error code.
349 If HAVE_ICONV is defined, CURL_ICONV_CODESET_OF_HOST must also
351 be defined. For example:
352 #define CURL_ICONV_CODESET_OF_HOST "IBM-1047"
354 The iconv code in libcurl will default the network and UTF8
356 codeset names as follows:
357 #define CURL_ICONV_CODESET_OF_NETWORK "ISO8859-1"
359 #define CURL_ICONV_CODESET_FOR_UTF8 "UTF-8"
361 You will need to override these definitions if they are differ‐
363 ent on your system.
364
366 CURLOPT_ERRORBUFFER
367 Pass a char * to a buffer that the libcurl may store human read‐
368 able error messages in. This may be more helpful than just the
369 return code from curl_easy_perform. The buffer must be at least
370 CURL_ERROR_SIZE big.
371 Use CURLOPT_VERBOSE and CURLOPT_DEBUGFUNCTION to better
373 debug/trace why errors happen.
374 If the library does not return an error, the buffer may not have
376 been touched. Do not rely on the contents in those cases.
377 CURLOPT_STDERR
380 Pass a FILE * as parameter. Tell libcurl to use this stream
381 instead of stderr when showing the progress meter and displaying
382 CURLOPT_VERBOSE data.
383 CURLOPT_FAILONERROR
385 A non-zero parameter tells the library to fail silently if the
386 HTTP code returned is equal to or larger than 400. The default
387 action would be to return the page normally, ignoring that code.
388 This method is not fail-safe and there are occasions where non-
390 successful response codes will slip through, especially when
391 authentication is involved (response codes 401 and 407).
392 You might get some amounts of headers transferred before this
394 situation is detected, like for when a "100-continue" is
395 received as a response to a POST/PUT and a 401 or 407 is
396 received immediately afterwards.
397
399 CURLOPT_URL
400 The actual URL to deal with. The parameter should be a char * to
401 a zero terminated string. The string must remain present until
402 curl no longer needs it, as it doesn't copy the string.
403 If the given URL lacks the protocol part ("http://" or "ftp://"
405 etc), it will attempt to guess which protocol to use based on
406 the given host name. If the given protocol of the set URL is not
407 supported, libcurl will return on error (CURLE_UNSUPPORTED_PRO‐
408 TOCOL) when you call curl_easy_perform(3) or curl_multi_per‐
409 form(3). Use curl_version_info(3) for detailed info on which
410 protocols that are supported.
411 The string given to CURLOPT_URL must be url-encoded and follow‐
413 ing the RFC 2396 (http://curl.haxx.se/rfc/rfc2396.txt).
414 CURLOPT_URL is the only option that must be set before
416 curl_easy_perform(3) is called.
417 CURLOPT_PROXY
419 Set HTTP proxy to use. The parameter should be a char * to a
420 zero terminated string holding the host name or dotted IP
421 address. To specify port number in this string, append :[port]
422 to the end of the host name. The proxy string may be prefixed
423 with [protocol]:// since any such prefix will be ignored. The
424 proxy's port number may optionally be specified with the sepa‐
425 rate option CURLOPT_PROXYPORT.
426 When you tell the library to use an HTTP proxy, libcurl will
428 transparently convert operations to HTTP even if you specify an
429 FTP URL etc. This may have an impact on what other features of
430 the library you can use, such as CURLOPT_QUOTE and similar FTP
431 specifics that don't work unless you tunnel through the HTTP
432 proxy. Such tunneling is activated with CURLOPT_HTTPPROXYTUNNEL.
433 libcurl respects the environment variables http_proxy,
435 ftp_proxy, all_proxy etc, if any of those is set. The CUR‐
436 LOPT_PROXY option does however override any possibly set envi‐
437 ronment variables.
438 Setting the proxy string to "" (an empty string) will explicitly
440 disable the use of a proxy, even if there is an environment
441 variable set for it.
442 Since 7.14.1, the proxy host string given in environment vari‐
444 ables can be specified the exact same way as the proxy can be
445 set with CURLOPT_PROXY, include protocol prefix (http://) and
446 embedded user + password.
447 CURLOPT_PROXYPORT
449 Pass a long with this option to set the proxy port to connect to
450 unless it is specified in the proxy string CURLOPT_PROXY.
451 CURLOPT_PROXYTYPE
453 Pass a long with this option to set type of the proxy. Available
454 options for this are CURLPROXY_HTTP, CURLPROXY_SOCKS4 (added in
455 7.15.2) CURLPROXY_SOCKS5. The HTTP type is default. (Added in
456 7.10)
457 CURLOPT_HTTPPROXYTUNNEL
459 Set the parameter to non-zero to get the library to tunnel all
460 operations through a given HTTP proxy. There is a big difference
461 between using a proxy and to tunnel through it. If you don't
462 know what this means, you probably don't want this tunneling
463 option.
464 CURLOPT_INTERFACE
466 Pass a char * as parameter. This set the interface name to use
467 as outgoing network interface. The name can be an interface
468 name, an IP address or a host name.
469 CURLOPT_LOCALPORT
471 Pass a long. This sets the local port number of the socket used
472 for connection. This can be used in combination with CUR‐
473 LOPT_INTERFACE and you are recommended to use CURLOPT_LOCALPOR‐
474 TRANGE as well when this is set. Note that port numbers are only
475 valid 1 - 65535. (Added in 7.15.2)
476 CURLOPT_LOCALPORTRANGE
478 Pass a long. This is the number of attempts libcurl should do to
479 find a working local port number. It starts with the given CUR‐
480 LOPT_LOCALPORT and adds one to the number for each retry. Set‐
481 ting this value to 1 or below will make libcurl do only one try
482 for exact port number. Note that port numbers by nature is a
483 scarce resource that will be busy at times so setting this value
484 to something too low might cause unnecessary connection setup
485 failures. (Added in 7.15.2)
486 CURLOPT_DNS_CACHE_TIMEOUT
488 Pass a long, this sets the timeout in seconds. Name resolves
489 will be kept in memory for this number of seconds. Set to zero
490 (0) to completely disable caching, or set to -1 to make the
491 cached entries remain forever. By default, libcurl caches this
492 info for 60 seconds.
493 CURLOPT_DNS_USE_GLOBAL_CACHE
495 Pass a long. If the value is non-zero, it tells curl to use a
496 global DNS cache that will survive between easy handle creations
497 and deletions. This is not thread-safe and this will use a
498 global variable.
499 WARNING: this option is considered obsolete. Stop using it.
501 Switch over to using the share interface instead! See CUR‐
502 LOPT_SHARE and curl_share_init(3).
503 CURLOPT_BUFFERSIZE
505 Pass a long specifying your preferred size (in bytes) for the
506 receive buffer in libcurl. The main point of this would be that
507 the write callback gets called more often and with smaller
508 chunks. This is just treated as a request, not an order. You
509 cannot be guaranteed to actually get the given size. (Added in
510 7.10)
511 This size is by default set as big as possible
513 (CURL_MAX_WRITE_SIZE), so it only makes sense to use this option
514 if you want it smaller.
515 CURLOPT_PORT
517 Pass a long specifying what remote port number to connect to,
518 instead of the one specified in the URL or the default port for
519 the used protocol.
520 CURLOPT_TCP_NODELAY
522 Pass a long specifying whether the TCP_NODELAY option should be
523 set or cleared (1 = set, 0 = clear). The option is cleared by
524 default. This will have no effect after the connection has been
525 established.
526 Setting this option will disable TCP's Nagle algorithm. The pur‐
528 pose of this algorithm is to try to minimize the number of small
529 packets on the network (where "small packets" means TCP segments
530 less than the Maximum Segment Size (MSS) for the network).
531 Maximizing the amount of data sent per TCP segment is good
533 because it amortizes the overhead of the send. However, in some
534 cases (most notably telnet or rlogin) small segments may need to
535 be sent without delay. This is less efficient than sending
536 larger amounts of data at a time, and can contribute to conges‐
537 tion on the network if overdone.
538
540 CURLOPT_NETRC
541 This parameter controls the preference of libcurl between using
542 user names and passwords from your ~/.netrc file, relative to
543 user names and passwords in the URL supplied with CURLOPT_URL.
544 libcurl uses a user name (and supplied or prompted password)
546 supplied with CURLOPT_USERPWD in preference to any of the
547 options controlled by this parameter.
548 Pass a long, set to one of the values described below.
550 CURL_NETRC_OPTIONAL
552 The use of your ~/.netrc file is optional, and informa‐
553 tion in the URL is to be preferred. The file will be
554 scanned with the host and user name (to find the password
555 only) or with the host only, to find the first user name
556 and password after that machine, which ever information
557 is not specified in the URL.
558 Undefined values of the option will have this effect.
560 CURL_NETRC_IGNORED
562 The library will ignore the file and use only the infor‐
563 mation in the URL.
564 This is the default.
566 CURL_NETRC_REQUIRED
568 This value tells the library that use of the file is
569 required, to ignore the information in the URL, and to
570 search the file with the host only.
571 Only machine name, user name and password are taken into account (init
572 macros and similar things aren't supported).
573 libcurl does not verify that the file has the correct properties set
575 (as the standard Unix ftp client does). It should only be readable by
576 user.
577 CURLOPT_NETRC_FILE
579 Pass a char * as parameter, pointing to a zero terminated string
580 containing the full path name to the file you want libcurl to
581 use as .netrc file. If this option is omitted, and CURLOPT_NETRC
582 is set, libcurl will attempt to find the a .netrc file in the
583 current user's home directory. (Added in 7.10.9)
584 CURLOPT_USERPWD
586 Pass a char * as parameter, which should be [user name]:[pass‐
587 word] to use for the connection. Use CURLOPT_HTTPAUTH to decide
588 authentication method.
589 When using NTLM, you can set domain by prepending it to the user
591 name and separating the domain and name with a forward (/) or
592 backward slash (\). Like this: "domain/user:password" or
593 "domain\user:password". Some HTTP servers (on Windows) support
594 this style even for Basic authentication.
595 When using HTTP and CURLOPT_FOLLOWLOCATION, libcurl might per‐
597 form several requests to possibly different hosts. libcurl will
598 only send this user and password information to hosts using the
599 initial host name (unless CURLOPT_UNRESTRICTED_AUTH is set), so
600 if libcurl follows locations to other hosts it will not send the
601 user and password to those. This is enforced to prevent acciden‐
602 tal information leakage.
603 CURLOPT_PROXYUSERPWD
605 Pass a char * as parameter, which should be [user name]:[pass‐
606 word] to use for the connection to the HTTP proxy. Use CUR‐
607 LOPT_PROXYAUTH to decide authentication method.
608 CURLOPT_HTTPAUTH
610 Pass a long as parameter, which is set to a bitmask, to tell
611 libcurl what authentication method(s) you want it to use. The
612 available bits are listed below. If more than one bit is set,
613 libcurl will first query the site to see what authentication
614 methods it supports and then pick the best one you allow it to
615 use. For some methods, this will induce an extra network round-
616 trip. Set the actual name and password with the CURLOPT_USERPWD
617 option. (Added in 7.10.6)
618 CURLAUTH_BASIC
620 HTTP Basic authentication. This is the default choice,
621 and the only method that is in wide-spread use and sup‐
622 ported virtually everywhere. This is sending the user
623 name and password over the network in plain text, easily
624 captured by others.
625 CURLAUTH_DIGEST
627 HTTP Digest authentication. Digest authentication is
628 defined in RFC2617 and is a more secure way to do authen‐
629 tication over public networks than the regular old-fash‐
630 ioned Basic method.
631 CURLAUTH_GSSNEGOTIATE
633 HTTP GSS-Negotiate authentication. The GSS-Negotiate
634 (also known as plain "Negotiate") method was designed by
635 Microsoft and is used in their web applications. It is
636 primarily meant as a support for Kerberos5 authentication
637 but may be also used along with another authentication
638 methods. For more information see IETF draft draft-
639 brezak-spnego-http-04.txt.
640 You need to build libcurl with a suitable GSS-API library
642 for this to work.
643 CURLAUTH_NTLM
645 HTTP NTLM authentication. A proprietary protocol invented
646 and used by Microsoft. It uses a challenge-response and
647 hash concept similar to Digest, to prevent the password
648 from being eavesdropped.
649 You need to build libcurl with OpenSSL support for this
651 option to work, or build libcurl on Windows.
652 CURLAUTH_ANY
654 This is a convenience macro that sets all bits and thus
655 makes libcurl pick any it finds suitable. libcurl will
656 automatically select the one it finds most secure.
657 CURLAUTH_ANYSAFE
659 This is a convenience macro that sets all bits except
660 Basic and thus makes libcurl pick any it finds suitable.
661 libcurl will automatically select the one it finds most
662 secure.
663 CURLOPT_PROXYAUTH
665 Pass a long as parameter, which is set to a bitmask, to tell
666 libcurl what authentication method(s) you want it to use for
667 your proxy authentication. If more than one bit is set, libcurl
668 will first query the site to see what authentication methods it
669 supports and then pick the best one you allow it to use. For
670 some methods, this will induce an extra network round-trip. Set
671 the actual name and password with the CURLOPT_PROXYUSERPWD
672 option. The bitmask can be constructed by or'ing together the
673 bits listed above for the CURLOPT_HTTPAUTH option. As of this
674 writing, only Basic, Digest and NTLM work. (Added in 7.10.7)
675
677 CURLOPT_AUTOREFERER
678 Pass a non-zero parameter to enable this. When enabled, libcurl
679 will automatically set the Referer: field in requests where it
680 follows a Location: redirect.
681 CURLOPT_ENCODING
683 Sets the contents of the Accept-Encoding: header sent in an HTTP
684 request, and enables decoding of a response when a Content-
685 Encoding: header is received. Three encodings are supported:
686 identity, which does nothing, deflate which requests the server
687 to compress its response using the zlib algorithm, and gzip
688 which requests the gzip algorithm. If a zero-length string is
689 set, then an Accept-Encoding: header containing all supported
690 encodings is sent.
691 This is a request, not an order; the server may or may not do
693 it. This option must be set (to any non-NULL value) or else any
694 unsolicited encoding done by the server is ignored. See the spe‐
695 cial file lib/README.encoding for details.
696 CURLOPT_FOLLOWLOCATION
698 A non-zero parameter tells the library to follow any Location:
699 header that the server sends as part of an HTTP header.
700 This means that the library will re-send the same request on the
702 new location and follow new Location: headers all the way until
703 no more such headers are returned. CURLOPT_MAXREDIRS can be used
704 to limit the number of redirects libcurl will follow.
705 CURLOPT_UNRESTRICTED_AUTH
707 A non-zero parameter tells the library it can continue to send
708 authentication (user+password) when following locations, even
709 when hostname changed. This option is meaningful only when set‐
710 ting CURLOPT_FOLLOWLOCATION.
711 CURLOPT_MAXREDIRS
713 Pass a long. The set number will be the redirection limit. If
714 that many redirections have been followed, the next redirect
715 will cause an error (CURLE_TOO_MANY_REDIRECTS). This option only
716 makes sense if the CURLOPT_FOLLOWLOCATION is used at the same
717 time. Added in 7.15.1: Setting the limit to 0 will make libcurl
718 refuse any redirect. Set it to -1 for an infinite number of
719 redirects (which is the default)
720 CURLOPT_PUT
722 A non-zero parameter tells the library to use HTTP PUT to trans‐
723 fer data. The data should be set with CURLOPT_READDATA and CUR‐
724 LOPT_INFILESIZE.
725 This option is deprecated and starting with version 7.12.1 you
727 should instead use CURLOPT_UPLOAD.
728 CURLOPT_POST
730 A non-zero parameter tells the library to do a regular HTTP
731 post. This will also make the library use the a "Content-Type:
732 application/x-www-form-urlencoded" header. (This is by far the
733 most commonly used POST method).
734 Use the CURLOPT_POSTFIELDS option to specify what data to post
736 and CURLOPT_POSTFIELDSIZE to set the data size.
737 Optionally, you can provide data to POST using the CURLOPT_READ‐
739 FUNCTION and CURLOPT_READDATA options but then you must make
740 sure to not set CURLOPT_POSTFIELDS to anything but NULL. When
741 providing data with a callback, you must transmit it using chun‐
742 ked transfer-encoding or you must set the size of the data with
743 the CURLOPT_POSTFIELDSIZE option.
744 You can override the default POST Content-Type: header by set‐
746 ting your own with CURLOPT_HTTPHEADER.
747 Using POST with HTTP 1.1 implies the use of a "Expect: 100-con‐
749 tinue" header. You can disable this header with CURLOPT_HTTP‐
750 HEADER as usual.
751 If you use POST to a HTTP 1.1 server, you can send data without
753 knowing the size before starting the POST if you use chunked
754 encoding. You enable this by adding a header like "Transfer-
755 Encoding: chunked" with CURLOPT_HTTPHEADER. With HTTP 1.0 or
756 without chunked transfer, you must specify the size in the
757 request.
758 When setting CURLOPT_POST to a non-zero value, it will automati‐
760 cally set CURLOPT_NOBODY to 0 (since 7.14.1).
761 If you issue a POST request and then want to make a HEAD or GET
763 using the same re-used handle, you must explicitly set the new
764 request type using CURLOPT_NOBODY or CURLOPT_HTTPGET or similar.
765 CURLOPT_POSTFIELDS
767 Pass a char * as parameter, which should be the full data to
768 post in an HTTP POST operation. You must make sure that the data
769 is formatted the way you want the server to receive it. libcurl
770 will not convert or encode it for you. Most web servers will
771 assume this data to be url-encoded. Take note.
772 This POST is a normal application/x-www-form-urlencoded kind
774 (and libcurl will set that Content-Type by default when this
775 option is used), which is the most commonly used one by HTML
776 forms. See also the CURLOPT_POST. Using CURLOPT_POSTFIELDS
777 implies CURLOPT_POST.
778 Using POST with HTTP 1.1 implies the use of a "Expect: 100-con‐
780 tinue" header. You can disable this header with CURLOPT_HTTP‐
781 HEADER as usual.
782 To make multipart/formdata posts (aka rfc1867-posts), check out
784 the CURLOPT_HTTPPOST option.
785 CURLOPT_POSTFIELDSIZE
787 If you want to post data to the server without letting libcurl
788 do a strlen() to measure the data size, this option must be
789 used. When this option is used you can post fully binary data,
790 which otherwise is likely to fail. If this size is set to -1,
791 the library will use strlen() to get the size.
792 CURLOPT_POSTFIELDSIZE_LARGE
794 Pass a curl_off_t as parameter. Use this to set the size of the
795 CURLOPT_POSTFIELDS data to prevent libcurl from doing strlen()
796 on the data to figure out the size. This is the large file ver‐
797 sion of the CURLOPT_POSTFIELDSIZE option. (Added in 7.11.1)
798 CURLOPT_HTTPPOST
800 Tells libcurl you want a multipart/formdata HTTP POST to be made
801 and you instruct what data to pass on to the server. Pass a
802 pointer to a linked list of curl_httppost structs as parameter.
803 . The easiest way to create such a list, is to use curl_for‐
804 madd(3) as documented. The data in this list must remain intact
805 until you close this curl handle again with
806 curl_easy_cleanup(3).
807 Using POST with HTTP 1.1 implies the use of a "Expect: 100-con‐
809 tinue" header. You can disable this header with CURLOPT_HTTP‐
810 HEADER as usual.
811 When setting CURLOPT_HTTPPOST, it will automatically set CUR‐
813 LOPT_NOBODY to 0 (since 7.14.1).
814 CURLOPT_REFERER
816 Pass a pointer to a zero terminated string as parameter. It will
817 be used to set the Referer: header in the http request sent to
818 the remote server. This can be used to fool servers or scripts.
819 You can also set any custom header with CURLOPT_HTTPHEADER.
820 CURLOPT_USERAGENT
822 Pass a pointer to a zero terminated string as parameter. It will
823 be used to set the User-Agent: header in the http request sent
824 to the remote server. This can be used to fool servers or
825 scripts. You can also set any custom header with CURLOPT_HTTP‐
826 HEADER.
827 CURLOPT_HTTPHEADER
829 Pass a pointer to a linked list of HTTP headers to pass to the
830 server in your HTTP request. The linked list should be a fully
831 valid list of struct curl_slist structs properly filled in. Use
832 curl_slist_append(3) to create the list and
833 curl_slist_free_all(3) to clean up an entire list. If you add a
834 header that is otherwise generated and used by libcurl inter‐
835 nally, your added one will be used instead. If you add a header
836 with no contents as in 'Accept:' (no data on the right side of
837 the colon), the internally used header will get disabled. Thus,
838 using this option you can add new headers, replace internal
839 headers and remove internal headers. To add a header with no
840 contents, make the contents be two quotes: "". The headers
841 included in the linked list must not be CRLF-terminated, because
842 curl adds CRLF after each header item. Failure to comply with
843 this will result in strange bugs because the server will most
844 likely ignore part of the headers you specified.
845 The first line in a request (containing the method, usually a
847 GET or POST) is not a header and cannot be replaced using this
848 option. Only the lines following the request-line are headers.
849 Adding this method line in this list of headers will only cause
850 your request to send an invalid header.
851 Pass a NULL to this to reset back to no custom headers.
853 The most commonly replaced headers have "shortcuts" in the
855 options CURLOPT_COOKIE, CURLOPT_USERAGENT and CURLOPT_REFERER.
856 CURLOPT_HTTP200ALIASES
858 Pass a pointer to a linked list of aliases to be treated as
859 valid HTTP 200 responses. Some servers respond with a custom
860 header response line. For example, IceCast servers respond with
861 "ICY 200 OK". By including this string in your list of aliases,
862 the response will be treated as a valid HTTP header line such as
863 "HTTP/1.0 200 OK". (Added in 7.10.3)
864 The linked list should be a fully valid list of struct
866 curl_slist structs, and be properly filled in. Use
867 curl_slist_append(3) to create the list and
868 curl_slist_free_all(3) to clean up an entire list.
869 The alias itself is not parsed for any version strings. Before
871 libcurl 7.16.3, Libcurl used the value set by option CUR‐
872 LOPT_HTTP_VERSION, but starting with 7.16.3 the protocol is
873 assumed to match HTTP 1.0 when an alias matched.
874 CURLOPT_COOKIE
876 Pass a pointer to a zero terminated string as parameter. It will
877 be used to set a cookie in the http request. The format of the
878 string should be NAME=CONTENTS, where NAME is the cookie name
879 and CONTENTS is what the cookie should contain.
880 If you need to set multiple cookies, you need to set them all
882 using a single option and thus you need to concatenate them all
883 in one single string. Set multiple cookies in one string like
884 this: "name1=content1; name2=content2;" etc.
885 Using this option multiple times will only make the latest
887 string override the previously ones.
888 CURLOPT_COOKIEFILE
890 Pass a pointer to a zero terminated string as parameter. It
891 should contain the name of your file holding cookie data to
892 read. The cookie data may be in Netscape / Mozilla cookie data
893 format or just regular HTTP-style headers dumped to a file.
894 Given an empty or non-existing file or by passing the empty
896 string (""), this option will enable cookies for this curl han‐
897 dle, making it understand and parse received cookies and then
898 use matching cookies in future request.
899 If you use this option multiple times, you just add more files
901 to read. Subsequent files will add more cookies.
902 CURLOPT_COOKIEJAR
904 Pass a file name as char *, zero terminated. This will make
905 libcurl write all internally known cookies to the specified file
906 when curl_easy_cleanup(3) is called. If no cookies are known, no
907 file will be created. Specify "-" to instead have the cookies
908 written to stdout. Using this option also enables cookies for
909 this session, so if you for example follow a location it will
910 make matching cookies get sent accordingly.
911 If the cookie jar file can't be created or written to (when the
913 curl_easy_cleanup(3) is called), libcurl will not and cannot
914 report an error for this. Using CURLOPT_VERBOSE or CUR‐
915 LOPT_DEBUGFUNCTION will get a warning to display, but that is
916 the only visible feedback you get about this possibly lethal
917 situation.
918 CURLOPT_COOKIESESSION
920 Pass a long set to non-zero to mark this as a new cookie "ses‐
921 sion". It will force libcurl to ignore all cookies it is about
922 to load that are "session cookies" from the previous session. By
923 default, libcurl always stores and loads all cookies, indepen‐
924 dent if they are session cookies are not. Session cookies are
925 cookies without expiry date and they are meant to be alive and
926 existing for this "session" only.
927 CURLOPT_COOKIELIST
929 Pass a char * to a cookie string. Cookie can be either in Net‐
930 scape / Mozilla format or just regular HTTP-style header (Set-
931 Cookie: ...) format. If cURL cookie engine was not enabled it
932 will enable its cookie engine. Passing a magic string "ALL"
933 will erase all cookies known by cURL. (Added in 7.14.1) Passing
934 the special string "SESS" will only erase all session cookies
935 known by cURL. (Added in 7.15.4)
936 CURLOPT_HTTPGET
938 Pass a long. If the long is non-zero, this forces the HTTP
939 request to get back to GET. usable if a POST, HEAD, PUT or a
940 custom request have been used previously using the same curl
941 handle.
942 When setting CURLOPT_HTTPGET to a non-zero value, it will auto‐
944 matically set CURLOPT_NOBODY to 0 (since 7.14.1).
945 CURLOPT_HTTP_VERSION
947 Pass a long, set to one of the values described below. They
948 force libcurl to use the specific HTTP versions. This is not
949 sensible to do unless you have a good reason.
950 CURL_HTTP_VERSION_NONE
952 We don't care about what version the library uses.
953 libcurl will use whatever it thinks fit.
954 CURL_HTTP_VERSION_1_0
956 Enforce HTTP 1.0 requests.
957 CURL_HTTP_VERSION_1_1
959 Enforce HTTP 1.1 requests.
960 CURLOPT_IGNORE_CONTENT_LENGTH
962 Ignore the Content-Length header. This is useful for Apache 1.x
963 (and similar servers) which will report incorrect content length
964 for files over 2 gigabytes. If this option is used, curl will
965 not be able to accurately report progress, and will simply stop
966 the download when the server ends the connection. (added in
967 7.14.1)
968 CURLOPT_HTTP_CONTENT_DECODING
970 Pass a long to tell libcurl how to act on content decoding. If
971 set to zero, content decoding will be disabled. If set to 1 it
972 is enabled. Note however that libcurl has no default content
973 decoding but requires you to use CURLOPT_ENCODING for that.
974 (added in 7.16.2)
975 CURLOPT_HTTP_TRANSFER_DECODING
977 Pass a long to tell libcurl how to act on transfer decoding. If
978 set to zero, transfer decoding will be disabled, if set to 1 it
979 is enabled (default). libcurl does chunked transfer decoding by
980 default unless this option is set to zero. (added in 7.16.2)
981
983 CURLOPT_FTPPORT
984 Pass a pointer to a zero terminated string as parameter. It will
985 be used to get the IP address to use for the ftp PORT instruc‐
986 tion. The PORT instruction tells the remote server to connect to
987 our specified IP address. The string may be a plain IP address,
988 a host name, an network interface name (under Unix) or just a
989 '-' letter to let the library use your systems default IP
990 address. Default FTP operations are passive, and thus won't use
991 PORT.
992 You disable PORT again and go back to using the passive version
994 by setting this option to NULL.
995 CURLOPT_QUOTE
997 Pass a pointer to a linked list of FTP or SFTP commands to pass
998 to the server prior to your ftp request. This will be done
999 before any other commands are issued (even before the CWD com‐
1000 mand for FTP). The linked list should be a fully valid list of
1001 'struct curl_slist' structs properly filled in with text
1002 strings. Use curl_slist_append(3) to append strings (commands)
1003 to the list, and clear the entire list afterwards with
1004 curl_slist_free_all(3). Disable this operation again by setting
1005 a NULL to this option.
1006 CURLOPT_POSTQUOTE
1008 Pass a pointer to a linked list of FTP or SFTP commands to pass
1009 to the server after your ftp transfer request. The linked list
1010 should be a fully valid list of struct curl_slist structs prop‐
1011 erly filled in as described for CURLOPT_QUOTE. Disable this
1012 operation again by setting a NULL to this option.
1013 CURLOPT_PREQUOTE
1015 Pass a pointer to a linked list of FTP commands to pass to the
1016 server after the transfer type is set. The linked list should be
1017 a fully valid list of struct curl_slist structs properly filled
1018 in as described for CURLOPT_QUOTE. Disable this operation again
1019 by setting a NULL to this option. Before version 7.15.6, if you
1020 also set CURLOPT_NOBODY non-zero, this option didn't work.
1021 CURLOPT_FTPLISTONLY
1023 A non-zero parameter tells the library to just list the names of
1024 an ftp directory, instead of doing a full directory listing that
1025 would include file sizes, dates etc.
1026 This causes an FTP NLST command to be sent. Beware that some
1028 FTP servers list only files in their response to NLST; they
1029 might not include subdirectories and symbolic links.
1030 CURLOPT_FTPAPPEND
1032 A non-zero parameter tells the library to append to the remote
1033 file instead of overwrite it. This is only useful when uploading
1034 to an ftp site.
1035 CURLOPT_FTP_USE_EPRT
1037 Pass a long. If the value is non-zero, it tells curl to use the
1038 EPRT (and LPRT) command when doing active FTP downloads (which
1039 is enabled by CURLOPT_FTPPORT). Using EPRT means that it will
1040 first attempt to use EPRT and then LPRT before using PORT, but
1041 if you pass FALSE (zero) to this option, it will not try using
1042 EPRT or LPRT, only plain PORT. (Added in 7.10.5)
1043 If the server is an IPv6 host, this option will have no effect
1045 as of 7.12.3.
1046 CURLOPT_FTP_USE_EPSV
1048 Pass a long. If the value is non-zero, it tells curl to use the
1049 EPSV command when doing passive FTP downloads (which it always
1050 does by default). Using EPSV means that it will first attempt to
1051 use EPSV before using PASV, but if you pass FALSE (zero) to this
1052 option, it will not try using EPSV, only plain PASV.
1053 If the server is an IPv6 host, this option will have no effect
1055 as of 7.12.3.
1056 CURLOPT_FTP_CREATE_MISSING_DIRS
1058 Pass a long. If the value is non-zero, curl will attempt to cre‐
1059 ate any remote directory that it fails to CWD into. CWD is the
1060 command that changes working directory. (Added in 7.10.7)
1061 This setting also applies to SFTP-connections. curl will attempt
1063 to create the remote directory if it can't obtain a handle to
1064 the target-location. The creation will fail if a file of the
1065 same name as the directory to create already exists or lack of
1066 permissions prevents creation. (Added in 7.16.3)
1067 CURLOPT_FTP_RESPONSE_TIMEOUT
1069 Pass a long. Causes curl to set a timeout period (in seconds)
1070 on the amount of time that the server is allowed to take in
1071 order to generate a response message for a command before the
1072 session is considered hung. While curl is waiting for a
1073 response, this value overrides CURLOPT_TIMEOUT. It is recom‐
1074 mended that if used in conjunction with CURLOPT_TIMEOUT, you set
1075 CURLOPT_FTP_RESPONSE_TIMEOUT to a value smaller than CUR‐
1076 LOPT_TIMEOUT. (Added in 7.10.8)
1077 CURLOPT_FTP_ALTERNATIVE_TO_USER
1079 Pass a char * as parameter, pointing to a string which will be
1080 used to authenticate if the usual FTP "USER user" and "PASS
1081 password" negotiation fails. This is currently only known to be
1082 required when connecting to Tumbleweed's Secure Transport FTPS
1083 server using client certificates for authentication. (Added in
1084 7.15.5)
1085 CURLOPT_FTP_SKIP_PASV_IP
1087 Pass a long. If set to a non-zero value, it instructs libcurl to
1088 not use the IP address the server suggests in its 227-response
1089 to libcurl's PASV command when libcurl connects the data connec‐
1090 tion. Instead libcurl will re-use the same IP address it already
1091 uses for the control connection. But it will use the port number
1092 from the 227-response. (Added in 7.14.2)
1093 This option has no effect if PORT, EPRT or EPSV is used instead
1095 of PASV.
1096 CURLOPT_FTP_SSL
1098 Pass a long using one of the values from below, to make libcurl
1099 use your desired level of SSL for the ftp transfer. (Added in
1100 7.11.0)
1101 CURLFTPSSL_NONE
1103 Don't attempt to use SSL.
1104 CURLFTPSSL_TRY
1106 Try using SSL, proceed as normal otherwise.
1107 CURLFTPSSL_CONTROL
1109 Require SSL for the control connection or fail with
1110 CURLE_FTP_SSL_FAILED.
1111 CURLFTPSSL_ALL
1113 Require SSL for all communication or fail with
1114 CURLE_FTP_SSL_FAILED.
1115 CURLOPT_FTPSSLAUTH
1117 Pass a long using one of the values from below, to alter how
1118 libcurl issues "AUTH TLS" or "AUTH SSL" when FTP over SSL is
1119 activated (see CURLOPT_FTP_SSL). (Added in 7.12.2)
1120 CURLFTPAUTH_DEFAULT
1122 Allow libcurl to decide
1123 CURLFTPAUTH_SSL
1125 Try "AUTH SSL" first, and only if that fails try "AUTH
1126 TLS"
1127 CURLFTPAUTH_TLS
1129 Try "AUTH TLS" first, and only if that fails try "AUTH
1130 SSL"
1131 CURLOPT_FTP_SSL_CCC
1133 If enabled, this option makes libcurl use CCC (Clear Command
1134 Channel). It shuts down the SSL/TLS layer after authenticating.
1135 The rest of the control channel communication will be unen‐
1136 crypted. This allows NAT routers to follow the FTP transaction.
1137 Pass a long using one of the values below. (Added in 7.16.1)
1138 CURLFTPSSL_CCC_NONE
1140 Don't attempt to use CCC.
1141 CURLFTPSSL_CCC_PASSIVE
1143 Do not initiate the shutdown, but wait for the server to
1144 do it. Do not send a reply.
1145 CURLFTPSSL_CCC_ACTIVE
1147 Initiate the shutdown and wait for a reply.
1148 CURLOPT_FTP_ACCOUNT
1150 Pass a pointer to a zero-terminated string (or NULL to disable).
1151 When an FTP server asks for "account data" after user name and
1152 password has been provided, this data is sent off using the ACCT
1153 command. (Added in 7.13.0)
1154 CURLOPT_FTP_FILEMETHOD
1156 Pass a long that should have one of the following values. This
1157 option controls what method libcurl should use to reach a file
1158 on a FTP(S) server. The argument should be one of the following
1159 alternatives:
1160 CURLFTPMETHOD_MULTICWD
1162 libcurl does a single CWD operation for each path part in
1163 the given URL. For deep hierarchies this means very many
1164 commands. This is how RFC1738 says it should be done.
1165 This is the default but the slowest behavior.
1166 CURLFTPMETHOD_NOCWD
1168 libcurl does no CWD at all. libcurl will do SIZE, RETR,
1169 STOR etc and give a full path to the server for all these
1170 commands. This is the fastest behavior.
1171 CURLFTPMETHOD_SINGLECWD
1173 libcurl does one CWD with the full target directory and
1174 then operates on the file "normally" (like in the multi‐
1175 cwd case). This is somewhat more standards compliant than
1176 'nocwd' but without the full penalty of 'multicwd'.
1177
1179 CURLOPT_TRANSFERTEXT
1180 A non-zero parameter tells the library to use ASCII mode for ftp
1181 transfers, instead of the default binary transfer. For win32
1182 systems it does not set the stdout to binary mode. This option
1183 can be usable when transferring text data between systems with
1184 different views on certain characters, such as newlines or simi‐
1185 lar.
1186 libcurl does not do a complete ASCII conversion when doing ASCII
1188 transfers over FTP. This is a known limitation/flaw that nobody
1189 has rectified. libcurl simply sets the mode to ascii and per‐
1190 forms a standard transfer.
1191 CURLOPT_CRLF
1193 Convert Unix newlines to CRLF newlines on transfers.
1194 CURLOPT_RANGE
1196 Pass a char * as parameter, which should contain the specified
1197 range you want. It should be in the format "X-Y", where X or Y
1198 may be left out. HTTP transfers also support several intervals,
1199 separated with commas as in "X-Y,N-M". Using this kind of multi‐
1200 ple intervals will cause the HTTP server to send the response
1201 document in pieces (using standard MIME separation techniques).
1202 Pass a NULL to this option to disable the use of ranges.
1203 CURLOPT_RESUME_FROM
1205 Pass a long as parameter. It contains the offset in number of
1206 bytes that you want the transfer to start from. Set this option
1207 to 0 to make the transfer start from the beginning (effectively
1208 disabling resume). For FTP, set this option to -1 to make the
1209 transfer start from the end of the target file (useful to con‐
1210 tinue an interrupted upload).
1211 CURLOPT_RESUME_FROM_LARGE
1213 Pass a curl_off_t as parameter. It contains the offset in number
1214 of bytes that you want the transfer to start from. (Added in
1215 7.11.0)
1216 CURLOPT_CUSTOMREQUEST
1218 Pass a pointer to a zero terminated string as parameter. It will
1219 be user instead of GET or HEAD when doing an HTTP request, or
1220 instead of LIST or NLST when doing an ftp directory listing.
1221 This is useful for doing DELETE or other more or less obscure
1222 HTTP requests. Don't do this at will, make sure your server sup‐
1223 ports the command first.
1224 Restore to the internal default by setting this to NULL.
1226 Many people have wrongly used this option to replace the entire
1228 request with their own, including multiple headers and POST con‐
1229 tents. While that might work in many cases, it will cause
1230 libcurl to send invalid requests and it could possibly confuse
1231 the remote server badly. Use CURLOPT_POST and CURLOPT_POSTFIELDS
1232 to set POST data. Use CURLOPT_HTTPHEADER to replace or extend
1233 the set of headers sent by libcurl. Use CURLOPT_HTTP_VERSION to
1234 change HTTP version.
1235 CURLOPT_FILETIME
1237 Pass a long. If it is a non-zero value, libcurl will attempt to
1238 get the modification date of the remote document in this opera‐
1239 tion. This requires that the remote server sends the time or
1240 replies to a time querying command. The curl_easy_getinfo(3)
1241 function with the CURLINFO_FILETIME argument can be used after a
1242 transfer to extract the received time (if any).
1243 CURLOPT_NOBODY
1245 A non-zero parameter tells the library to not include the body-
1246 part in the output. This is only relevant for protocols that
1247 have separate header and body parts. On HTTP(S) servers, this
1248 will make libcurl do a HEAD request.
1249 To change request to GET, you should use CURLOPT_HTTPGET. Change
1251 request to POST with CURLOPT_POST etc.
1252 CURLOPT_INFILESIZE
1254 When uploading a file to a remote site, this option should be
1255 used to tell libcurl what the expected size of the infile is.
1256 This value should be passed as a long. See also CURLOPT_INFILE‐
1257 SIZE_LARGE.
1258 For uploading using SCP, this option or CURLOPT_INFILESIZE_LARGE
1260 is mandatory.
1261 Note that this option does not limit how much data libcurl will
1263 actually send, as that is controlled entirely by what the read
1264 callback returns.
1265 CURLOPT_INFILESIZE_LARGE
1267 When uploading a file to a remote site, this option should be
1268 used to tell libcurl what the expected size of the infile is.
1269 This value should be passed as a curl_off_t. (Added in 7.11.0)
1270 For uploading using SCP, this option or CURLOPT_INFILESIZE is
1272 mandatory.
1273 Note that this option does not limit how much data libcurl will
1275 actually send, as that is controlled entirely by what the read
1276 callback returns.
1277 CURLOPT_UPLOAD
1279 A non-zero parameter tells the library to prepare for an upload.
1280 The CURLOPT_READDATA and CURLOPT_INFILESIZE or CURLOPT_INFILE‐
1281 SIZE_LARGE options are also interesting for uploads. If the pro‐
1282 tocol is HTTP, uploading means using the PUT request unless you
1283 tell libcurl otherwise.
1284 Using PUT with HTTP 1.1 implies the use of a "Expect: 100-con‐
1286 tinue" header. You can disable this header with CURLOPT_HTTP‐
1287 HEADER as usual.
1288 If you use PUT to a HTTP 1.1 server, you can upload data without
1290 knowing the size before starting the transfer if you use chunked
1291 encoding. You enable this by adding a header like "Transfer-
1292 Encoding: chunked" with CURLOPT_HTTPHEADER. With HTTP 1.0 or
1293 without chunked transfer, you must specify the size.
1294 CURLOPT_MAXFILESIZE
1296 Pass a long as parameter. This allows you to specify the maximum
1297 size (in bytes) of a file to download. If the file requested is
1298 larger than this value, the transfer will not start and
1299 CURLE_FILESIZE_EXCEEDED will be returned.
1300 The file size is not always known prior to download, and for
1302 such files this option has no effect even if the file transfer
1303 ends up being larger than this given limit. This concerns both
1304 FTP and HTTP transfers.
1305 CURLOPT_MAXFILESIZE_LARGE
1307 Pass a curl_off_t as parameter. This allows you to specify the
1308 maximum size (in bytes) of a file to download. If the file
1309 requested is larger than this value, the transfer will not start
1310 and CURLE_FILESIZE_EXCEEDED will be returned. (Added in 7.11.0)
1311 The file size is not always known prior to download, and for
1313 such files this option has no effect even if the file transfer
1314 ends up being larger than this given limit. This concerns both
1315 FTP and HTTP transfers.
1316 CURLOPT_TIMECONDITION
1318 Pass a long as parameter. This defines how the CURLOPT_TIMEVALUE
1319 time value is treated. You can set this parameter to CURL_TIME‐
1320 COND_IFMODSINCE or CURL_TIMECOND_IFUNMODSINCE. This feature
1321 applies to HTTP and FTP.
1322 The last modification time of a file is not always known and in
1324 such instances this feature will have no effect even if the
1325 given time condition would have not been met.
1326 CURLOPT_TIMEVALUE
1328 Pass a long as parameter. This should be the time in seconds
1329 since 1 jan 1970, and the time will be used in a condition as
1330 specified with CURLOPT_TIMECONDITION.
1331
1333 CURLOPT_TIMEOUT
1334 Pass a long as parameter containing the maximum time in seconds
1335 that you allow the libcurl transfer operation to take. Normally,
1336 name lookups can take a considerable time and limiting opera‐
1337 tions to less than a few minutes risk aborting perfectly normal
1338 operations. This option will cause curl to use the SIGALRM to
1339 enable time-outing system calls.
1340 In unix-like systems, this might cause signals to be used unless
1342 CURLOPT_NOSIGNAL is set.
1343 CURLOPT_TIMEOUT_MS
1345 Like CURLOPT_TIMEOUT but takes number of milliseconds instead.
1346 If libcurl is built to use the standard system name resolver,
1347 that part will still use full-second resolution for timeouts.
1348 (Added in 7.16.2)
1349 CURLOPT_LOW_SPEED_LIMIT
1351 Pass a long as parameter. It contains the transfer speed in
1352 bytes per second that the transfer should be below during CUR‐
1353 LOPT_LOW_SPEED_TIME seconds for the library to consider it too
1354 slow and abort.
1355 CURLOPT_LOW_SPEED_TIME
1357 Pass a long as parameter. It contains the time in seconds that
1358 the transfer should be below the CURLOPT_LOW_SPEED_LIMIT for the
1359 library to consider it too slow and abort.
1360 CURLOPT_MAX_SEND_SPEED_LARGE
1362 Pass a curl_off_t as parameter. If an upload exceeds this speed
1363 on cumulative average during the transfer, the transfer will
1364 pause to keep the average rate less than or equal to the parame‐
1365 ter value. Defaults to unlimited speed. (Added in 7.15.5)
1366 CURLOPT_MAX_RECV_SPEED_LARGE
1368 Pass a curl_off_t as parameter. If a download exceeds this
1369 speed on cumulative average during the transfer, the transfer
1370 will pause to keep the average rate less than or equal to the
1371 parameter value. Defaults to unlimited speed. (Added in 7.15.5)
1372 CURLOPT_MAXCONNECTS
1374 Pass a long. The set number will be the persistent connection
1375 cache size. The set amount will be the maximum amount of simul‐
1376 taneously open connections that libcurl may cache in this easy
1377 handle. Default is 5, and there isn't much point in changing
1378 this value unless you are perfectly aware of how this work and
1379 changes libcurl's behaviour. This concerns connection using any
1380 of the protocols that support persistent connections.
1381 When reaching the maximum limit, curl closes the oldest one in
1383 the cache to prevent the number of open connections to increase.
1384 If you already have performed transfers with this curl handle,
1386 setting a smaller MAXCONNECTS than before may cause open connec‐
1387 tions to get closed unnecessarily.
1388 Note that if you add this easy handle to a multi handle, this
1390 setting is not being acknowledged, but you must instead use
1391 curl_multi_setopt(3) and the CURLMOPT_MAXCONNECTS option.
1392 CURLOPT_CLOSEPOLICY
1394 (Obsolete) This option does nothing.
1395 CURLOPT_FRESH_CONNECT
1397 Pass a long. Set to non-zero to make the next transfer use a new
1398 (fresh) connection by force. If the connection cache is full
1399 before this connection, one of the existing connections will be
1400 closed as according to the selected or default policy. This
1401 option should be used with caution and only if you understand
1402 what it does. Set this to 0 to have libcurl attempt re-using an
1403 existing connection (default behavior).
1404 CURLOPT_FORBID_REUSE
1406 Pass a long. Set to non-zero to make the next transfer explic‐
1407 itly close the connection when done. Normally, libcurl keep all
1408 connections alive when done with one transfer in case there
1409 comes a succeeding one that can re-use them. This option should
1410 be used with caution and only if you understand what it does.
1411 Set to 0 to have libcurl keep the connection open for possibly
1412 later re-use (default behavior).
1413 CURLOPT_CONNECTTIMEOUT
1415 Pass a long. It should contain the maximum time in seconds that
1416 you allow the connection to the server to take. This only lim‐
1417 its the connection phase, once it has connected, this option is
1418 of no more use. Set to zero to disable connection timeout (it
1419 will then only timeout on the system's internal timeouts). See
1420 also the CURLOPT_TIMEOUT option.
1421 In unix-like systems, this might cause signals to be used unless
1423 CURLOPT_NOSIGNAL is set.
1424 CURLOPT_CONNECTTIMEOUT_MS
1426 Like CURLOPT_CONNECTTIMEOUT but takes number of milliseconds
1427 instead. If libcurl is built to use the standard system name
1428 resolver, that part will still use full-second resolution for
1429 timeouts. (Added in 7.16.2)
1430 CURLOPT_IPRESOLVE
1432 Allows an application to select what kind of IP addresses to use
1433 when resolving host names. This is only interesting when using
1434 host names that resolve addresses using more than one version of
1435 IP. The allowed values are:
1436 CURL_IPRESOLVE_WHATEVER
1438 Default, resolves addresses to all IP versions that your
1439 system allows.
1440 CURL_IPRESOLVE_V4
1442 Resolve to ipv4 addresses.
1443 CURL_IPRESOLVE_V6
1445 Resolve to ipv6 addresses.
1446 CURLOPT_CONNECT_ONLY
1448 Pass a long. A non-zero parameter tells the library to perform
1449 any required proxy authentication and connection setup, but no
1450 data transfer.
1451 This option is useful with the CURLINFO_LASTSOCKET option to
1453 curl_easy_getinfo(3). The library can set up the connection and
1454 then the application can obtain the most recently used socket
1455 for special data transfers. (Added in 7.15.2)
1456
1458 CURLOPT_SSLCERT
1459 Pass a pointer to a zero terminated string as parameter. The
1460 string should be the file name of your certificate. The default
1461 format is "PEM" and can be changed with CURLOPT_SSLCERTTYPE.
1462 With NSS this is the nickname of the certificate you wish to
1464 authenticate with.
1465 CURLOPT_SSLCERTTYPE
1467 Pass a pointer to a zero terminated string as parameter. The
1468 string should be the format of your certificate. Supported for‐
1469 mats are "PEM" and "DER". (Added in 7.9.3)
1470 CURLOPT_SSLCERTPASSWD
1472 Pass a pointer to a zero terminated string as parameter. It will
1473 be used as the password required to use the CURLOPT_SSLCERT cer‐
1474 tificate.
1475 This option is replaced by CURLOPT_SSLKEYPASSWD and should only
1477 be used for backward compatibility. You never needed a pass
1478 phrase to load a certificate but you need one to load your pri‐
1479 vate key.
1480 CURLOPT_SSLKEY
1482 Pass a pointer to a zero terminated string as parameter. The
1483 string should be the file name of your private key. The default
1484 format is "PEM" and can be changed with CURLOPT_SSLKEYTYPE.
1485 CURLOPT_SSLKEYTYPE
1487 Pass a pointer to a zero terminated string as parameter. The
1488 string should be the format of your private key. Supported for‐
1489 mats are "PEM", "DER" and "ENG".
1490 The format "ENG" enables you to load the private key from a
1492 crypto engine. In this case CURLOPT_SSLKEY is used as an identi‐
1493 fier passed to the engine. You have to set the crypto engine
1494 with CURLOPT_SSLENGINE. "DER" format key file currently does
1495 not work because of a bug in OpenSSL.
1496 CURLOPT_SSLKEYPASSWD
1498 Pass a pointer to a zero terminated string as parameter. It will
1499 be used as the password required to use the CURLOPT_SSLKEY or
1500 CURLOPT_SSH_PRIVATE_KEYFILE private key.
1501 CURLOPT_SSLENGINE
1503 Pass a pointer to a zero terminated string as parameter. It will
1504 be used as the identifier for the crypto engine you want to use
1505 for your private key.
1506 If the crypto device cannot be loaded, CURLE_SSL_ENGINE_NOTFOUND
1508 is returned.
1509 CURLOPT_SSLENGINE_DEFAULT
1511 Sets the actual crypto engine as the default for (asymmetric)
1512 crypto operations.
1513 If the crypto device cannot be set, CURLE_SSL_ENGINE_SETFAILED
1515 is returned.
1516 CURLOPT_SSLVERSION
1518 Pass a long as parameter to control what version of SSL/TLS to
1519 attempt to use. The available options are:
1520 CURL_SSLVERSION_DEFAULT
1522 The default action. When libcurl built with OpenSSL or
1523 NSS, this will attempt to figure out the remote SSL pro‐
1524 tocol version. Unfortunately there are a lot of ancient
1525 and broken servers in use which cannot handle this tech‐
1526 nique and will fail to connect. When libcurl is built
1527 with GnuTLS, this will mean SSLv3.
1528 CURL_SSLVERSION_TLSv1
1530 Force TLSv1
1531 CURL_SSLVERSION_SSLv2
1533 Force SSLv2
1534 CURL_SSLVERSION_SSLv3
1536 Force SSLv3
1537 CURLOPT_SSL_VERIFYPEER
1539 Pass a long as parameter.
1540 This option determines whether curl verifies the authenticity of
1542 the peer's certificate. A nonzero value means curl verifies;
1543 zero means it doesn't. The default is nonzero, but before 7.10,
1544 it was zero.
1545 When negotiating an SSL connection, the server sends a certifi‐
1547 cate indicating its identity. Curl verifies whether the cer‐
1548 tificate is authentic, i.e. that you can trust that the server
1549 is who the certificate says it is. This trust is based on a
1550 chain of digital signatures, rooted in certification authority
1551 (CA) certificates you supply. As of 7.10, curl installs a
1552 default bundle of CA certificates and you can specify alternate
1553 certificates with the CURLOPT_CAINFO option or the CURLOPT_CAP‐
1554 ATH option.
1555 When CURLOPT_SSL_VERIFYPEER is nonzero, and the verification
1557 fails to prove that the certificate is authentic, the connection
1558 fails. When the option is zero, the connection succeeds regard‐
1559 less.
1560 Authenticating the certificate is not by itself very useful.
1562 You typically want to ensure that the server, as authentically
1563 identified by its certificate, is the server you mean to be
1564 talking to. Use CURLOPT_SSL_VERIFYHOST to control that.
1565 CURLOPT_CAINFO
1567 Pass a char * to a zero terminated string naming a file holding
1568 one or more certificates to verify the peer with. This makes
1569 sense only when used in combination with the CURLOPT_SSL_VERI‐
1570 FYPEER option. If CURLOPT_SSL_VERIFYPEER is zero, CUR‐
1571 LOPT_CAINFO need not even indicate an accessible file.
1572 Note that option is by default set to the system path where
1574 libcurl's cacert bundle is assumed to be stored, as established
1575 at build time.
1576 When built against NSS this is the directory that the NSS cer‐
1578 tificate database resides in.
1579 CURLOPT_CAPATH
1581 Pass a char * to a zero terminated string naming a directory
1582 holding multiple CA certificates to verify the peer with. The
1583 certificate directory must be prepared using the openssl
1584 c_rehash utility. This makes sense only when used in combination
1585 with the CURLOPT_SSL_VERIFYPEER option. If CURLOPT_SSL_VERI‐
1586 FYPEER is zero, CURLOPT_CAPATH need not even indicate an acces‐
1587 sible path. The CURLOPT_CAPATH function apparently does not
1588 work in Windows due to some limitation in openssl. This option
1589 is OpenSSL-specific and does nothing if libcurl is built to use
1590 GnuTLS.
1591 CURLOPT_RANDOM_FILE
1593 Pass a char * to a zero terminated file name. The file will be
1594 used to read from to seed the random engine for SSL. The more
1595 random the specified file is, the more secure the SSL connection
1596 will become.
1597 CURLOPT_EGDSOCKET
1599 Pass a char * to the zero terminated path name to the Entropy
1600 Gathering Daemon socket. It will be used to seed the random
1601 engine for SSL.
1602 CURLOPT_SSL_VERIFYHOST
1604 Pass a long as parameter.
1605 This option determines whether libcurl verifies that the server
1607 cert is for the server it is known as.
1608 When negotiating an SSL connection, the server sends a certifi‐
1610 cate indicating its identity.
1611 When CURLOPT_SSL_VERIFYHOST is 2, that certificate must indicate
1613 that the server is the server to which you meant to connect, or
1614 the connection fails.
1615 Curl considers the server the intended one when the Common Name
1617 field or a Subject Alternate Name field in the certificate
1618 matches the host name in the URL to which you told Curl to con‐
1619 nect.
1620 When the value is 1, the certificate must contain a Common Name
1622 field, but it doesn't matter what name it says. (This is not
1623 ordinarily a useful setting).
1624 When the value is 0, the connection succeeds regardless of the
1626 names in the certificate.
1627 The default, since 7.10, is 2.
1629 The checking this option controls is of the identity that the
1631 server claims. The server could be lying. To control lying,
1632 see CURLOPT_SSL_VERIFYPEER.
1633 CURLOPT_SSL_CIPHER_LIST
1635 Pass a char *, pointing to a zero terminated string holding the
1636 list of ciphers to use for the SSL connection. The list must be
1637 syntactically correct, it consists of one or more cipher strings
1638 separated by colons. Commas or spaces are also acceptable sepa‐
1639 rators but colons are normally used, , - and + can be used as
1640 operators.
1641 For OpenSSL and GnuTLS valid examples of cipher lists include
1643 'RC4-SHA', ´SHA1+DES´, 'TLSv1' and 'DEFAULT'. The default list
1644 is normally set when you compile OpenSSL.
1645 You'll find more details about cipher lists on this URL:
1647 http://www.openssl.org/docs/apps/ciphers.html
1648 For NSS valid examples of cipher lists include
1650 'rsa_rc4_128_md5', ´rsa_aes_128_sha´, etc. With NSS you don't
1651 add/remove ciphers. If one uses this option then all known
1652 ciphers are disabled and only those passed in are enabled.
1653 You'll find more details about the NSS cipher lists on this URL:
1655 http://directory.fedora.redhat.com/docs/mod_nss.html#Directives
1656 CURLOPT_SSL_SESSIONID_CACHE
1659 Pass a long set to 0 to disable libcurl's use of SSL session-ID
1660 caching. Set this to 1 to enable it. By default all transfers
1661 are done using the cache. Note that while nothing ever should
1662 get hurt by attempting to reuse SSL session-IDs, there seem to
1663 be broken SSL implementations in the wild that may require you
1664 to disable this in order for you to succeed. (Added in 7.16.0)
1665 CURLOPT_KRBLEVEL
1667 Pass a char * as parameter. Set the kerberos security level for
1668 FTP; this also enables kerberos awareness. This is a string,
1669 'clear', 'safe', of these, 'private' will be used. Set the
1670 string to NULL to disable kerberos support for FTP.
1671 (This option was known as CURLOPT_KRB4LEVEL up to 7.16.3)
1673
1675 CURLOPT_SSH_AUTH_TYPES
1676 Pass a long set to a bitmask consisting of one or more of
1677 CURLSSH_AUTH_PUBLICKEY, CURLSSH_AUTH_PASSWORD,
1678 CURLSSH_AUTH_HOST, CURLSSH_AUTH_KEYBOARD. Set CURLSSH_AUTH_ANY
1679 to let libcurl pick one.
1680 CURLOPT_SSH_PUBLIC_KEYFILE
1682 Pass a char * pointing to a file name for your public key. If
1683 not used, libcurl defaults to using ~/.ssh/id_dsa.pub.
1684 CURLOPT_SSH_PRIVATE_KEYFILE
1686 Pass a char * pointing to a file name for your private key. If
1687 not used, libcurl defaults to using ~/.ssh/id_dsa. If the file
1688 is password-protected, set the password with CURLOPT_SSLKEY‐
1689 PASSWD.
1690
1692 CURLOPT_PRIVATE
1693 Pass a char * as parameter, pointing to data that should be
1694 associated with this curl handle. The pointer can subsequently
1695 be retrieved using curl_easy_getinfo(3) with the CURLINFO_PRI‐
1696 VATE option. libcurl itself does nothing with this data. (Added
1697 in 7.10.3)
1698 CURLOPT_SHARE
1700 Pass a share handle as a parameter. The share handle must have
1701 been created by a previous call to curl_share_init(3). Setting
1702 this option, will make this curl handle use the data from the
1703 shared handle instead of keeping the data to itself. This
1704 enables several curl handles to share data. If the curl handles
1705 are used simultaneously, you MUST use the locking methods in the
1706 share handle. See curl_share_setopt(3) for details.
1707 CURLOPT_NEW_FILE_PERMS
1709 Pass a long as a parameter, containing the value of the permis‐
1710 sions that will be assigned to newly created files on the remote
1711 server. The default value is 0644, but any valid value can be
1712 used. The only protocols that can use this are sftp://, scp://
1713 and file://. (Added in 7.16.4)
1714 CURLOPT_NEW_DIRECTORY_PERMS
1716 Pass a long as a parameter, containing the value of the permis‐
1717 sions that will be assigned to newly created directories on the
1718 remote server. The default value is 0755, but any valid value
1719 can be used. The only protocols that can use this are sftp://,
1720 scp:// and file://. (Added in 7.16.4)
1721
1723 CURLOPT_TELNETOPTIONS
1724 Provide a pointer to a curl_slist with variables to pass to the
1725 telnet negotiations. The variables should be in the format
1726 <option=value>. libcurl supports the options 'TTYPE', 'XDISPLOC'
1727 and 'NEW_ENV'. See the TELNET standard for details.
1728
1730 CURLE_OK (zero) means that the option was set properly, non-zero means
1731 an error occurred as <curl/curl.h> defines. See the libcurl-errors(3)
1732 man page for the full list with descriptions.
1733 If you try to set an option that libcurl doesn't know about, perhaps
1735 because the library is too old to support it or the option was removed
1736 in a recent version, this function will return CURLE_FAILED_INIT.
1737
1739 curl_easy_init(3), curl_easy_cleanup(3), curl_easy_reset(3),
1740libcurl 7.16.2 22 Feb 2007 curl_easy_setopt(3)