Section 3: library functions
CURLOPT_HTTPPROXYTUNNEL – tunnel through HTTP proxy Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTPPROXYTUNNEL, long tunnel); DescriptionSet the parameter to 1 to make libcurl tunnel all operations through the HTTP proxy. There is a big difference between using a proxy and to tunnel through it. If you don’t know what this means, you probably don’t want this…
CURLOPT_HTTPPOST – specify the multipart formpost content Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTPPOST, struct curl_httppost *formpost);DescriptionTells libcurl you want a multipart/formdata HTTP POST to be made and you instruct what data to pass on to the server in the formpost argument. Pass a pointer to a linked list of curl_httppost structs as parameter. The easiest…
CURLOPT_HTTPHEADER – set custom HTTP headers Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTPHEADER, struct curl_slist *headers); DescriptionPass a pointer to a linked list of HTTP headers to pass to the server and/or proxy in your HTTP request. The same list can be used for both host and proxy requests! The linked list should be a fully…
CURLOPT_HTTPGET – ask for a HTTP GET request Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTPGET, long useget); DescriptionPass a long. If useget is 1, this forces the HTTP request to get back to using GET. Usable if a POST, HEAD, PUT, etc has been used previously using the same curl handle. When setting CURLOPT_HTTPGET(3) to 1,…
CURLOPT_HTTPAUTH – set HTTP server authentication methods to try Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTPAUTH, 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 speaking to the remote server. The available bits are listed below. If more than one bit is…
CURLOPT_HTTP200ALIASES – specify alternative matches for HTTP 200 OK Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTP200ALIASES, struct curl_slist *aliases);DescriptionPass a pointer to a linked list of aliases to be treated as valid HTTP 200 responses. Some servers respond with a custom header response line. For example, IceCast servers respond with "ICY 200 OK". By including this…
CURLOPT_HEADEROPT – set how to send HTTP headers Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HEADEROPT, long bitmask); DescriptionPass a long that is a bitmask of options of how to deal with headers. The two mutually exclusive options are: CURLHEADER_UNIFIED – keep working as before. This means CURLOPT_HTTPHEADER(3) headers will be used in requests both to servers…
CURLOPT_HEADERFUNCTION – callback that receives header data Synopsis#include <curl/curl.h> size_t header_callback(char *buffer, size_t size, size_t nitems, void *userdata); CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HEADERFUNCTION, header_callback); DescriptionPass a pointer to your callback function, which should match the prototype shown above. This function gets called by libcurl as soon as it has received header data. The header callback will be…
CURLOPT_HEADERDATA – pointer to pass to header callback Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HEADERDATA, void *pointer); DescriptionPass a pointer to be used to write the header part of the received data to. If CURLOPT_WRITEFUNCTION(3) or CURLOPT_HEADERFUNCTION(3) is used, pointer will be passed in to the respective callback. If neither of those options are set, pointer…
CURLOPT_HEADER – pass headers to the data stream Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HEADER, long onoff); DescriptionPass in onoff set to 1 to tell the library to include the header in the body output for requests with this handle. This option is relevant for protocols that actually have headers or other meta-data (like HTTP and…
CURLOPT_GSSAPI_DELEGATION – set allowed GSS-API delegation Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_GSSAPI_DELEGATION, long level); DescriptionSet the long parameter level to CURLGSSAPI_DELEGATION_FLAG to allow unconditional GSSAPI credential delegation. The delegation is disabled by default since 7.21.7. Set the parameter to CURLGSSAPI_DELEGATION_POLICY_FLAG to delegate only if the OK-AS-DELEGATE flag is set in the service ticket in case…
CURLOPT_FTP_USE_PRET – enable the PRET command Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_USE_PRET, long enable); DescriptionPass a long. If the value is 1, it tells curl to send a PRET command before PASV (and EPSV). Certain FTP servers, mainly drftpd, require this non-standard command for directory listings as well as up and downloads in PASV mode….
CURLOPT_FTP_USE_EPSV – enable/disable use of EPSV Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_USE_EPSV, long epsv); DescriptionPass epsv as a long. If the value is 1, it tells curl to use the EPSV command when doing passive FTP downloads (which it does by default). Using EPSV means that it will first attempt to use EPSV before using…
CURLOPT_FTP_USE_EPRT – enable/disable use of EPRT with FTP Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_USE_EPRT, long enabled); DescriptionPass a long. If the value is 1, it tells curl to use the EPRT command when doing active FTP downloads (which is enabled by CURLOPT_FTPPORT(3)). Using EPRT means that it will first attempt to use EPRT before using…
CURLOPT_FTP_SSL_CCC – switch off SSL again with FTP after auth Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_SSL_CCC, long how); DescriptionIf enabled, this option makes libcurl use CCC (Clear Command Channel). It shuts down the SSL/TLS layer after authenticating. The rest of the control channel communication will be unencrypted. This allows NAT routers to follow the FTP…
CURLOPT_FTP_SKIP_PASV_IP – ignore the IP address in the PASV response Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_SKIP_PASV_IP, long skip); DescriptionPass a long. If skip is set to 1, it instructs libcurl to not use the IP address the server suggests in its 227-response to libcurl’s PASV command when libcurl connects the data connection. Instead libcurl will…
CURLOPT_FTP_RESPONSE_TIMEOUT – time allowed to wait for FTP response Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_RESPONSE_TIMEOUT, long timeout); DescriptionPass a long. Causes libcurl to set a timeout period (in seconds) on the amount of time that the server is allowed to take in order to send a response message for a command before the session is…
CURLOPT_FTP_FILEMETHOD – select directory traversing method for FTP Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_FILEMETHOD, long method);DescriptionPass a long telling libcurl which method to use to reach a file on a FTP(S) server. This option exists because some server implementations aren’t compliant to what the standards say should work. The argument should be one of the…
CURLOPT_FTP_CREATE_MISSING_DIRS – create missing dirs for FTP and SFTP Synopsis#include <curl/curl.h> typedef enum { CURLFTP_CREATE_DIR_NONE, CURLFTP_CREATE_DIR, CURLFTP_CREATE_DIR_RETRY } curl_ftpcreatedir; CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_CREATE_MISSING_DIRS, long create);DescriptionPass a long telling libcurl to create the dir. If the value is CURLFTP_CREATE_DIR (1), libcurl will attempt to create any remote directory that it fails to "move" into. For FTP…
CURLOPT_FTP_ALTERNATIVE_TO_USER – command to use instead of USER with FTP Synopsis#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_ALTERNATIVE_TO_USER, char *cmd);DescriptionPass a char * as parameter, pointing to a string which will be used to authenticate if the usual FTP "USER user" and "PASS password" negotiation fails. This is currently only known to be required when connecting to…