---
name: "CURLOPT_CONNECT_ONLY"
section: "3"
platform: "macos"
package: "curl"
version: "166.0.0.0.1"
release: "macOS 26.5"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLOPT_CONNECT_ONLY"
---

# CURLOPT\_CONNECT\_ONLY(3)

stop when connected to target server

## NAME

CURLOPT\_CONNECT\_ONLY - stop when connected to target server

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CONNECT_ONLY, long only);
```

## DESCRIPTION

Pass a long. If the parameter equals 1, it tells the library to perform all the required proxy authentication and connection setup, but no data transfer, and then return.

The option can be used to simply test a connection to a server, but is more useful when used with the *[CURLINFO\_ACTIVESOCKET(3)](/CURLINFO_ACTIVESOCKET/3.md)* option to *[curl\_easy\_getinfo(3)](/curl_easy_getinfo/3.md)* as the library can set up the connection and then the application can obtain the most recently used socket for special data transfers.

Since 7.86.0, this option can be set to '2' and if HTTP or WebSocket are used, libcurl performs the request and reads all response headers before handing over control to the application.

Transfers marked connect only do not reuse any existing connections and connections marked connect only are not allowed to get reused.

If the connect only transfer is done using the multi interface, the particular easy handle must remain added to the multi handle for as long as the application wants to use it. Once it has been removed with *[curl\_multi\_remove\_handle(3)](/curl_multi_remove_handle/3.md)*, *[curl\_easy\_send(3)](/curl_easy_send/3.md)* and *[curl\_easy\_recv(3)](/curl_easy_recv/3.md)* do not function.

## DEFAULT

0

## PROTOCOLS

HTTP, SMTP, POP3 and IMAP. For WS and WSS starting in 7.86.0.

## EXAMPLE

```
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode ret;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 1L);
    ret = curl_easy_perform(curl);
    if(ret == CURLE_OK) {
      /* only connected! */
    }
  }
}
```

## AVAILABILITY

Added in 7.15.2

## RETURN VALUE

Returns CURLE\_OK if the option is supported, and CURLE\_UNKNOWN\_OPTION if not.

## SEE ALSO

[**CURLOPT\_HTTPPROXYTUNNEL**(3)](/CURLOPT_HTTPPROXYTUNNEL/3.md), [**CURLOPT\_VERBOSE**(3)](/CURLOPT_VERBOSE/3.md), [**curl\_easy\_recv**(3)](/curl_easy_recv/3.md), [**curl\_easy\_send**(3)](/curl_easy_send/3.md)