Section 3: library functions
CURLOPT_CAPATH – specify directory holding CA certificates Synopsis #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CAPATH, char *capath); Description 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….
CURLOPT_CAINFO – path to Certificate Authority (CA) bundle Synopsis #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CAINFO, char *path); Description Pass a char * to a zero terminated string naming a file holding one or more certificates to verify the peer with. If CURLOPT_SSL_VERIFYPEER(3) is zero and you avoid verifying the server’s certificate, CURLOPT_CAINFO(3) need not even…
CURLOPT_BUFFERSIZE – set preferred receive buffer size Synopsis #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_BUFFERSIZE, long size); Description 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…
CURLOPT_AUTOREFERER – automatically update the referer header Synopsis #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_AUTOREFERER, long autorefer); Description Pass a parameter set to 1 to enable this. When enabled, libcurl will automatically set the Referer: header field in HTTP requests where it follows a Location: redirect. Default 0, disabled Protocols HTTP Example TODO Availability Along with…
CURLOPT_APPEND – enable appending to the remote file Synopsis #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_APPEND, long append); Description 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. Default 0 Protocols FTP Example TODO Availability This option…
CURLOPT_ADDRESS_SCOPE – set scope for local IPv6 addresses Synopsis #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ADDRESS_SCOPE, long scope); Description Pass a long specifying the scope_id value to use when connecting to IPv6 link-local or site-local addresses. Default 0 Protocols All, when using IPv6 Example TODO Availability Added in 7.19.0 Return Value Returns CURLE_OK if the option…
CURLOPT_ACCEPT_ENCODING – enables automatic decompression of HTTP downloads Synopsis #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ACCEPT_ENCODING, char *enc); Description Pass a char * argument specifying what encoding you’d like. 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…
CURLOPT_ACCEPTTIMEOUT_MS – timeout waiting for FTP server to connect back Synopsis #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ACCEPTTIMEOUT_MS, long ms); Description 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. Default If no timeout is set, the internal…
CURLMOPT_TIMERFUNCTION – set callback to receive timeout values Synopsis #include <curl/curl.h> int timer_callback(CURLM *multi, /* multi handle */ long timeout_ms, /* see above */ void *userp); /* private callback pointer */ CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_TIMERFUNCTION, timer_callback); Description Pass a pointer to your callback function, which should match the prototype shown above. This callback function will…
CURLMOPT_TIMERDATA – custom pointer to pass to timer callback Synopsis #include <curl/curl.h> CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_TIMERDATA, void *pointer); Description A data pointer to pass to the timer callback set with the CURLMOPT_TIMERFUNCTION(3) option. This pointer will not be touched by libcurl but will only be passed in to the timer callbacks’s userp argument. Default NULL…
CURLMOPT_SOCKETFUNCTION – callback informed about what to wait for Synopsis #include <curl/curl.h> int socket_callback(CURL *easy, /* easy handle */ curl_socket_t s, /* socket */ int what, /* see above */ void *userp, /* private callback pointer */ void *socketp); /* private socket pointer */ CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETFUNCTION, socket_callback); Description Pass a pointer to your…
CURLMOPT_SOCKETDATA – custom pointer passed to the socket callback Synopsis #include <curl/curl.h> CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETDATA, void *pointer); Description A data pointer to pass to the socket callback set with the CURLMOPT_SOCKETFUNCTION(3) option. This pointer will not be touched by libcurl but will only be passed in to the socket callbacks’s userp argument. Default NULL…
CURLMOPT_PIPELINING_SITE_BL – pipelining host blacklist Synopsis #include <curl/curl.h> CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_PIPELINING_SITE_BL, char **hosts); Description Pass a hosts array of char *, ending with a NULL entry. This is a list of sites that are blacklisted from pipelining, i.e sites that are known to not support HTTP pipelining. The array is copied by libcurl. Pass…
CURLMOPT_PIPELINING_SERVER_BL – pipelining server blacklist Synopsis #include <curl/curl.h> CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_PIPELINING_SERVER_BL, char **servers); Description Pass a servers array of char *, ending with a NULL entry. This is a list of server types prefixes (in the Server: HTTP header) that are blacklisted from pipelining, i.e server types that are known to not support HTTP…
CURLMOPT_PIPELINING – enable/disable HTTP pipelining Synopsis #include <curl/curl.h> CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_PIPELINING, bool onoff); Description Set the onoff parameter to 1 to make libcurl use HTTP pipelining for HTTP transfers done using this multi handle, as far as possible. This means that if you add a second request that can use an already existing connection,…
CURLMOPT_MAX_TOTAL_CONNECTIONS – max simultaneously open connections Synopsis #include <curl/curl.h> CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_MAX_TOTAL_CONNECTIONS, long amount); Description Pass a long for the amount. The set number will be used as the maximum number of simultaneously open connections in total using this multi handle. For each new session, libcurl will open a new connection up to the…
CURLMOPT_MAX_PIPELINE_LENGTH – maximum number of requests in a pipeline Synopsis #include <curl/curl.h> CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_MAX_PIPELINE_LENGTH, long max); Description Pass a long. The set max number will be used as the maximum amount of outstanding requests in a pipelined connection. Only used if pipelining is enabled. When this limit is reached, libcurl will use another…
CURLMOPT_MAX_HOST_CONNECTIONS – set max number of connections to a single host Synopsis #include <curl/curl.h> CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_MAX_HOST_CONNECTIONS, long max); Description Pass a long to indicate max. The set number will be used as the maximum amount of simultaneously open connections to a single host. For each new session to a host, libcurl will open…
CURLMOPT_MAXCONNECTS – set size of connection cache Synopsis #include <curl/curl.h> CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_MAXCONNECTS, long max); Description Pass a long indicating the max. The set number will be used as the maximum amount of simultaneously open connections that libcurl may keep in its connection cache after completed use. By default libcurl will enlarge the size…
CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE – size threshold for pipelining penalty Synopsis #include <curl/curl.h> CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE, long size); Description Pass a long with a size in bytes. If a pipelined connection is currently processing a request with a Content-Length larger than this CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE(3), that pipeline will then not be considered for additional requests, even if it is…