NAME

       CURLOPT_PROXY - proxy to use

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY, char *proxy);

DESCRIPTION

       Set the proxy to use for the upcoming request. The parameter should be a char * to a null-
       terminated string holding the host name or dotted numerical IP address. A  numerical  IPv6
       address must be written within [brackets].

       To  specify  port  number  in this string, append :[port] to the end of the host name. The
       proxy's  port  number   may   optionally   be   specified   with   the   separate   option
       CURLOPT_PROXYPORT(3).  If  not  specified,  libcurl  will  default  to using port 1080 for
       proxies.

       The proxy string may be prefixed with [scheme]:// to specify which kind of proxy is used.

              http://
                     HTTP Proxy. Default when no scheme or proxy type is specified.

              https://
                     HTTPS Proxy. (Added in 7.52.0 for OpenSSL, GnuTLS and NSS. Since 7.87.0,  it
                     also  works  for  BearSSL,  mbedTLS,  rustls, Schannel, Secure Transport and
                     wolfSSL.)

                     This  will  use  HTTP/1  by   default.   Setting   CURLOPT_PROXYTYPE(3)   to
                     CURLPROXY_HTTPS2 allows libcurl to negotiate using HTTP/2 with proxy.

              socks4://
                     SOCKS4 Proxy.

              socks4a://
                     SOCKS4a Proxy. Proxy resolves URL hostname.

              socks5://
                     SOCKS5 Proxy.

              socks5h://
                     SOCKS5 Proxy. Proxy resolves URL hostname.

       Without  a  scheme prefix, CURLOPT_PROXYTYPE(3) can be used to specify which kind of proxy
       the string identifies.

       When you tell the library to  use  an  HTTP  proxy,  libcurl  will  transparently  convert
       operations  to  HTTP  even  if you specify an FTP URL etc. This may have an impact on what
       other features of the library you can  use,  such  as  CURLOPT_QUOTE(3)  and  similar  FTP
       specifics  that  do  not  work unless you tunnel through the HTTP proxy. Such tunneling is
       activated with CURLOPT_HTTPPROXYTUNNEL(3).

       Setting the proxy string to "" (an empty string) will explicitly  disable  the  use  of  a
       proxy, even if there is an environment variable set for it.

       A  proxy  host  string  can  also  include  protocol  scheme (http://) and embedded user +
       password.

       Unix domain sockets are supported for socks proxies since 7.84.0. Set  localhost  for  the
       host part. e.g. socks5h://localhost/path/to/socket.sock

       The application does not have to keep the string around after setting this option.

       When a proxy is used, the active FTP mode as set with CUROPT_FTPPORT(3), cannot be used.

Environment variables

       libcurl  respects  the proxy environment variables named http_proxy, ftp_proxy, sftp_proxy
       etc. If set, libcurl will use the specified proxy for that URL scheme. So for  a  "FTP://"
       URL, the ftp_proxy is considered. all_proxy is used if no protocol specific proxy was set.

       If   no_proxy   (or  NO_PROXY)  is  set,  it  is  the  exact  equivalent  of  setting  the
       CURLOPT_NOPROXY(3) option.

       The CURLOPT_PROXY(3) and CURLOPT_NOPROXY(3) options override environment variables.

DEFAULT

       Default is NULL, meaning no proxy is used.

       When you set a host name to use, do not assume that there's  any  particular  single  port
       number used widely for proxies. Specify it!

PROTOCOLS

       All except file://. Note that some protocols do not work well over proxy.

EXAMPLE

       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/file.txt");
         curl_easy_setopt(curl, CURLOPT_PROXY, "http://proxy:80");
         curl_easy_perform(curl);
       }

AVAILABILITY

       Since 7.14.1 the proxy environment variable names can include the protocol scheme.

       Since 7.21.7 the proxy string supports the socks protocols as "schemes".

       Since 7.50.2, unsupported schemes in proxy strings cause libcurl to return error.

       curl built to use NSS cannot connect to an HTTPS server over a unix domain socket.

RETURN VALUE

       Returns   CURLE_OK   if   proxies   are   supported,   CURLE_UNKNOWN_OPTION   if  not,  or
       CURLE_OUT_OF_MEMORY if there was insufficient heap space.

SEE ALSO

       CURLOPT_PROXYPORT(3), CURLOPT_HTTPPROXYTUNNEL(3), CURLOPT_PROXYTYPE(3)