NAME

       CURLOPT_PROTOCOLS_STR - allowed protocols

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROTOCOLS_STR, char *spec);

DESCRIPTION

       Pass  a pointer to a string that holds a comma-separated list of case insensitive protocol
       names (URL schemes) to allow in the transfer.  This  option  allows  applications  to  use
       libcurl  built  to support a wide range of protocols but still limit specific transfers to
       only be allowed to use a subset of them. By default, libcurl accepts all protocols it  was
       built with support for. See also CURLOPT_REDIR_PROTOCOLS_STR(3).

       If  trying  to  set  a  non-existing protocol or if no matching protocol at all is set, it
       returns error.

       These are the available protocols:

       DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3,
       POP3S, RTMP, RTMPE, RTMPS, RTMPT, RTMPTE, RTMPTS, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS,
       TELNET, TFTP, WS, WSS

       You can set "ALL" as a short-cut to enable all protocols. Note that by  setting  all,  you
       may  enable protocols that were not supported the day you write this but are introduced in
       a future libcurl version.

       curl_version_info(3) can be used to get a list of all supported protocols in  the  current
       libcurl.  CURLINFO_SCHEME(3)  is  the recommended way to figure out the protocol used in a
       previous transfer.

       Using this option multiple times makes the last set string override the previous ones. Set
       it to NULL to restore to the internal default.

DEFAULT

       All protocols built-in

PROTOCOLS

       This functionality affects all supported protocols

EXAMPLE

       int main(int argc, char **argv)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           /* pass in the URL from an external source */
           curl_easy_setopt(curl, CURLOPT_URL, argv[1]);

           /* only allow HTTP, TFTP and SFTP */
           curl_easy_setopt(curl, CURLOPT_PROTOCOLS_STR, "http,tftp,sftp");

           /* Perform the request */
           curl_easy_perform(curl);
         }
       }

AVAILABILITY

       Added in curl 7.85.0

RETURN VALUE

       Returns  CURLE_UNKNOWN_OPTION if the option is not implemented, CURLE_UNSUPPORTED_PROTOCOL
       if a listed protocol is not  supported  or  disabled,  CURLE_BAD_FUNCTION_ARGUMENT  if  no
       protocol is listed else CURLE_OK.

SEE ALSO

       CURLINFO_SCHEME(3),      CURLOPT_DEFAULT_PROTOCOL(3),      CURLOPT_REDIR_PROTOCOLS_STR(3),
       CURLOPT_URL(3), curl_version_info(3)