curl/docs/libcurl/opts/CURLOPT_PROTOCOLS_STR.3

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.TH CURLOPT_PROTOCOLS_STR 3 "11 Jun 2022" libcurl 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
All
.SH EXAMPLE
.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_STR, "http,tftp,sftp");

  /* Perform the request */
  curl_easy_perform(curl);
}
.fi
.SH AVAILABILITY
Added in 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 CURLOPT_REDIR_PROTOCOLS_STR "(3), " CURLOPT_URL "(3), "
.BR curl_version_info "(3), " CURLINFO_SCHEME "(3), "