opts: added examples

docs/libcurl/opts/CURLOPT_PROTOCOLS.3

@@ -32,14 +32,57 @@ Pass a long that holds a bitmask of CURLPROTO_* defines. If used, this bitmask
 limits what protocols libcurl may use in the transfer. This allows you to have
 a 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 will
-accept all protocols it supports. See also
+accept all protocols it supports (\fICURLPROTO_ALL\fP). See also
 \fICURLOPT_REDIR_PROTOCOLS(3)\fP.
+
+These are the available protocol defines:
+.nf
+CURLPROTO_DICT
+CURLPROTO_FILE
+CURLPROTO_FTP
+CURLPROTO_FTPS
+CURLPROTO_GOPHER
+CURLPROTO_HTTP
+CURLPROTO_HTTPS
+CURLPROTO_IMAP
+CURLPROTO_IMAPS
+CURLPROTO_LDAP
+CURLPROTO_LDAPS
+CURLPROTO_POP3
+CURLPROTO_POP3S
+CURLPROTO_RTMP
+CURLPROTO_RTMPE
+CURLPROTO_RTMPS
+CURLPROTO_RTMPT
+CURLPROTO_RTMPTE
+CURLPROTO_RTMPTS
+CURLPROTO_RTSP
+CURLPROTO_SCP
+CURLPROTO_SFTP
+CURLPROTO_SMTP
+CURLPROTO_SMTPS
+CURLPROTO_TELNET
+CURLPROTO_TFTP
+.fi
 .SH DEFAULT
 All protocols built-in
 .SH PROTOCOLS
 All
 .SH EXAMPLE
-TODO
+.nf
+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,
+                   CURLPROTO_HTTP | CURLPROTO_TFTP | CURLPROTO_SFTP);
+
+  /* Perform the request */
+  curl_easy_perform(curl);
+}
+.fi
 .SH AVAILABILITY
 Added in 7.19.4
 .SH RETURN VALUE