CURLINFO_PROTOCOL(3) Introduction to Library Functions CURLINFO_PROTOCOL(3)
CURLINFO_PROTOCOL - URL scheme used in transfer
#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_PROTOCOL, long *p);
This option is deprecated. We strongly recommend using
CURLINFO_SCHEME(3) instead, because this option cannot return all
possible schemes. The scheme might also sometimes be referred to as
the protocol.
Pass a pointer to a long to receive the scheme used in the last
transfer. The returned value is set to one of these values:
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_SMB, CURLPROTO_SMBS, CURLPROTO_SMTP,
CURLPROTO_SMTPS, CURLPROTO_TELNET, CURLPROTO_TFTP, CURLPROTO_MQTT
This functionality affects all supported protocols
int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode result;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
result = curl_easy_perform(curl);
if(result == CURLE_OK) {
long scheme;
curl_easy_getinfo(curl, CURLINFO_PROTOCOL, &scheme);
}
curl_easy_cleanup(curl);
}
}
Deprecated since 7.85.0.
Added in curl 7.52.0
curl_easy_getinfo(3) returns a CURLcode indicating success or error.
CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3).
CURLINFO_RESPONSE_CODE(3), curl_easy_getinfo(3), curl_easy_setopt(3)
libcurl 2026-01-08 CURLINFO_PROTOCOL(3)
NAME
CURLINFO_PROTOCOL - URL scheme used in transfer
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_PROTOCOL, long *p);
DESCRIPTION
This option is deprecated. We strongly recommend using
CURLINFO_SCHEME(3) instead, because this option cannot return all
possible schemes. The scheme might also sometimes be referred to as
the protocol.
Pass a pointer to a long to receive the scheme used in the last
transfer. The returned value is set to one of these values:
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_SMB, CURLPROTO_SMBS, CURLPROTO_SMTP,
CURLPROTO_SMTPS, CURLPROTO_TELNET, CURLPROTO_TFTP, CURLPROTO_MQTT
PROTOCOLS
This functionality affects all supported protocols
EXAMPLE
int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode result;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
result = curl_easy_perform(curl);
if(result == CURLE_OK) {
long scheme;
curl_easy_getinfo(curl, CURLINFO_PROTOCOL, &scheme);
}
curl_easy_cleanup(curl);
}
}
DEPRECATED
Deprecated since 7.85.0.
AVAILABILITY
Added in curl 7.52.0
RETURN VALUE
curl_easy_getinfo(3) returns a CURLcode indicating success or error.
CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3).
SEE ALSO
CURLINFO_RESPONSE_CODE(3), curl_easy_getinfo(3), curl_easy_setopt(3)
libcurl 2026-01-08 CURLINFO_PROTOCOL(3)