Section 3: library functions
CURLOPT_WRITEFUNCTION – set callback for writing received data Synopsis#include <curl/curl.h> size_t write_callback(char *ptr, size_t size, size_t nmemb, void *userdata); CURLcode curl_easy_setopt(CURL *handle, CURLOPT_WRITEFUNCTION, write_callback);DescriptionPass a pointer to your callback function, which should match the prototype shown above. This callback function gets called by libcurl as soon as there is data received that needs to be…
CURLOPT_WRITEDATA – custom pointer passed to the write callback Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_WRITEDATA, void *pointer); DescriptionA data pointer to pass to the write callback. If you use the CURLOPT_WRITEFUNCTION(3) option, this is the pointer you’ll get in that callback’s 4th argument. If you don’t use a write callback, you must make pointer a…
CURLOPT_WILDCARDMATCH – enable directory wildcard transfers Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_WILDCARDMATCH, long onoff); DescriptionSet onoff to 1 if you want to transfer multiple files according to a file name pattern. The pattern can be specified as part of the CURLOPT_URL(3) option, using an fnmatch-like pattern (Shell Pattern Matching) in the last part of URL…
CURLOPT_VERBOSE – set verbose mode on/off Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_VERBOSE, long onoff); DescriptionSet the onoff parameter to 1 to make the library display a lot of verbose information about its operations on this handle. Very useful for libcurl and/or protocol debugging and understanding. The verbose information will be sent to stderr, or the…
CURLOPT_USE_SSL – request using SSL / TLS for the transfer Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_USE_SSL, long level); DescriptionPass a long using one of the values from below, to make libcurl use your desired level of SSL for the transfer. These are all protocols that start out plain text and get "upgraded" to SSL using…
CURLOPT_USERPWD – user name and password to use in authentication Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_USERPWD, char *userpwd); DescriptionPass a char * as parameter, pointing to a zero terminated login details string for the connection. The format of which is: [user name]:[password]. When using Kerberos V5 authentication with a Windows based server, you should specify…
CURLOPT_USERNAME – user name to use in authentication Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_USERNAME, char *username);DescriptionPass a char * as parameter, which should be pointing to the zero terminated user name to use for the transfer. CURLOPT_USERNAME(3) sets the user name to be used in protocol authentication. You should not use this option together with…
CURLOPT_USERAGENT – set HTTP user-agent header Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_USERAGENT, char *ua); DescriptionPass 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…
CURLOPT_URL – provide the URL to use in the request Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_URL, char *URL); DescriptionPass in a pointer to the URL to work 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…
CURLOPT_UPLOAD – enable data upload Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UPLOAD, long upload); DescriptionThe long parameter upload set to 1 tells the library to prepare for and perform an upload. The CURLOPT_READDATA(3) and CURLOPT_INFILESIZE(3) or CURLOPT_INFILESIZE_LARGE(3) options are also interesting for uploads. If the protocol is HTTP, uploading means using the PUT request unless you…
CURLOPT_UNRESTRICTED_AUTH – send credentials to other hosts too Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UNRESTRICTED_AUTH, long goahead);DescriptionA long parameter set to 1 tells libcurl it can continue to send authentication (user+password) credentials when following locations, even when hostname changed. This option is meaningful only when setting CURLOPT_FOLLOWLOCATION(3). Default0 ProtocolsHTTP ExampleTODO AvailabilityAlong with HTTP Return ValueReturns CURLE_OK…
CURLOPT_UNIX_SOCKET_PATH – set Unix domain socket Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UNIX_SOCKET_PATH, char *path); DescriptionEnables the use of Unix domain sockets as connection endpoint and sets the path to path. If path is NULL, then Unix domain sockets are disabled. An empty string will result in an error at some point, it will not disable…
CURLOPT_TRANSFER_ENCODING – ask for HTTP Transfer Encoding Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TRANSFER_ENCODING, long enable); DescriptionPass a long set to 1 to enable or 0 to disable. 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…
CURLOPT_TRANSFERTEXT – request a text based transfer for FTP Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TRANSFERTEXT, long text); DescriptionA 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…
CURLOPT_TLSAUTH_USERNAME – user name to use for TLS authentication Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TLSAUTH_USERNAME, char *user); DescriptionPass a char * as parameter, which should point to the zero terminated username to use for the TLS authentication method specified with the CURLOPT_TLSAUTH_TYPE(3) option. Requires that the CURLOPT_TLSAUTH_PASSWORD(3) option also be set. DefaultNULL ProtocolsAll TLS-based protocols…
CURLOPT_TLSAUTH_TYPE – set TLS authentication methods Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TLSAUTH_TYPE, long bitmask); DescriptionPass 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. CURL_TLSAUTH_SRP TLS-SRP authentication. Secure Remote Password authentication for TLS is defined in RFC5054 and provides mutual…
CURLOPT_TLSAUTH_PASSWORD – password to use for TLS authentication Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TLSAUTH_PASSWORD, char *pwd); DescriptionPass a char * as parameter, which should point to the zero terminated password to use for the TLS authentication method specified with the CURLOPT_TLSAUTH_TYPE(3) option. Requires that the CURLOPT_TLSAUTH_USERNAME(3) option also be set. DefaultNULL ProtocolsAll TLS-based protocols ExampleTODO…
CURLOPT_TIMEVALUE – set time value for conditional Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TIMEVALUE, long val); DescriptionPass a long val as parameter. This should be the time counted as seconds since 1 Jan 1970, and the time will be used in a condition as specified with CURLOPT_TIMECONDITION(3). Default0 ProtocolsHTTP, FTP, RTSP, and FILE ExampleTODO AvailabilityAlways Return…
CURLOPT_TIMEOUT_MS – set maximum time the request is allowed to take Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TIMEOUT_MS, long timeout); DescriptionPass a long as parameter containing timeout – the maximum time in milliseconds that you allow the libcurl transfer operation to take. Normally, name lookups can take a considerable time and limiting operations to less than…
CURLOPT_TIMEOUT – set maximum time the request is allowed to take Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TIMEOUT, long timeout); DescriptionPass a long as parameter containing timeout – 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…