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CURLOPT_PROXY(3)                    libcurl                   CURLOPT_PROXY(3)

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)

ibcurl 8.1.2                    April 27, 2023                CURLOPT_PROXY(3)