.\" generated by cd2nroff 0.1 from CURLOPT_PROTOCOLS_STR.md
.TH CURLOPT_PROTOCOLS_STR 3 "2024-11-18" 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.
.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)