---
name: "CURLINFO_OS_ERRNO"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLINFO_OS_ERRNO"
---

# CURLINFO\_OS\_ERRNO(3)

errno number from last connect failure

## NAME

CURLINFO\_OS\_ERRNO - errno number from last connect failure

## SYNOPSIS

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

## DESCRIPTION

Pass a pointer to a long to receive the errno variable from a connect failure. Note that the value is only set on failure, it is not reset upon a successful operation. The number is OS and system specific.

libcurl network-related errors that may have a saved errno are: CURLE\_COULDNT\_CONNECT, CURLE\_FAILED\_INIT, CURLE\_INTERFACE\_FAILED, CURLE\_OPERATION\_TIMEDOUT, CURLE\_RECV\_ERROR, CURLE\_SEND\_ERROR.

Since 8.8.0 libcurl clears the easy handle's saved errno before performing the transfer. Prior versions did not clear the saved errno, which means if a saved errno is retrieved it could be from a previous transfer on the same handle.

## 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 error;
      result = curl_easy_getinfo(curl, CURLINFO_OS_ERRNO, &error);
      if(!result && error) {
        printf("Errno: %ld\n", error);
      }
    }
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

Added in curl 7.12.2

## RETURN VALUE

*[curl\_easy\_getinfo(3)](/curl_easy_getinfo/3.md)* returns a CURLcode indicating success or error.

CURLE\_OK (0) means everything was OK, non-zero means an error occurred, see *[libcurl-errors(3)](/libcurl-errors/3.md)*.

## SEE ALSO

[**curl\_easy\_getinfo**(3)](/curl_easy_getinfo/3.md), [**curl\_easy\_setopt**(3)](/curl_easy_setopt/3.md)