CURLINFO\_PROTOCOL(3) Library Functions Manual CURLINFO\_PROTOCOL(3)

# [NAME](#NAME)

CURLINFO\_PROTOCOL - URL scheme used in transfer

# [SYNOPSIS](#SYNOPSIS)

```
#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_PROTOCOL, long *p);
```

# [DESCRIPTION](#DESCRIPTION)

This option is deprecated. We strongly recommend using [*CURLINFO\_SCHEME(3)*](/man/os/curl/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_SMTP, CURLPROTO_SMTPS,
CURLPROTO_TELNET, CURLPROTO_TFTP, CURLPROTO_MQTT
```

# [PROTOCOLS](#PROTOCOLS)

This functionality affects all supported protocols

# [EXAMPLE](#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)

Deprecated since 7.85.0.

# [AVAILABILITY](#AVAILABILITY)

Added in curl 7.52.0

# [RETURN VALUE](#RETURN_VALUE)

[*curl\_easy\_getinfo(3)*](/man/os/curl/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)*](/man/os/curl/libcurl-errors.3).

# [SEE ALSO](#SEE_ALSO)

[**CURLINFO\_RESPONSE\_CODE**(3)](/man/os/curl/CURLINFO_RESPONSE_CODE.3), [**curl\_easy\_getinfo**(3)](/man/os/curl/curl_easy_getinfo.3), [**curl\_easy\_setopt**(3)](/man/os/curl/curl_easy_setopt.3)

2026-10-31 libcurl

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Document: CURLINFO_PROTOCOL(3) from curl 8.23.0-r3 (Chainguard OS)
Source: https://github.com/curl/curl.git