.\" generated by cd2nroff 0.1 from CURLOPT_PROTOCOLS_STR.md
.TH CURLOPT_PROTOCOLS_STR 3 "2024-12-25" libcurl
.SH NAME
CURLOPT_PROTOCOLS_STR \- allowed protocols
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROTOCOLS_STR, char *spec);
.fi
.SH 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 \fICURLOPT_REDIR_PROTOCOLS_STR(3)\fP.

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.

\fIcurl_version_info(3)\fP can be used to get a list of all supported protocols in
the current libcurl. \fICURLINFO_SCHEME(3)\fP 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.
.SH DEFAULT
All protocols built\-in
.SH PROTOCOLS
This functionality affects all supported protocols
.SH EXAMPLE
.nf
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);
  }
}
.fi
.SH AVAILABILITY
Added in curl 7.85.0
.SH 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.
.SH SEE ALSO
.BR CURLINFO_SCHEME (3),
.BR CURLOPT_DEFAULT_PROTOCOL (3),
.BR CURLOPT_REDIR_PROTOCOLS_STR (3),
.BR CURLOPT_URL (3),
.BR curl_version_info (3)