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* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
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* furnished to do so, under the terms of the COPYING file.
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* SPDX-License-Identifier: curl
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CURLOPT_PROTOCOLS_STR - allowed protocols

#include <curl/curl.h>

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

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. All protocols built-in All

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);
}

Added in 7.85.0 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. CURLOPT_REDIR_PROTOCOLS_STR "(3), " CURLOPT_URL "(3), " curl_version_info "(3), " CURLINFO_SCHEME "(3), "