xref: /curl/docs/libcurl/opts/CURLINFO_OS_ERRNO.md (revision 5a488251)
1---
2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
3SPDX-License-Identifier: curl
4Title: CURLINFO_OS_ERRNO
5Section: 3
6Source: libcurl
7See-also:
8  - curl_easy_getinfo (3)
9  - curl_easy_setopt (3)
10Protocol:
11  - All
12Added-in: 7.12.2
13---
14
15# NAME
16
17CURLINFO_OS_ERRNO - get errno number from last connect failure
18
19# SYNOPSIS
20
21~~~c
22#include <curl/curl.h>
23
24CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_OS_ERRNO, long *errnop);
25~~~
26
27# DESCRIPTION
28
29Pass a pointer to a long to receive the errno variable from a connect failure.
30Note that the value is only set on failure, it is not reset upon a successful
31operation. The number is OS and system specific.
32
33libcurl network-related errors that may have a saved errno are:
34CURLE_COULDNT_CONNECT, CURLE_FAILED_INIT, CURLE_INTERFACE_FAILED,
35CURLE_OPERATION_TIMEDOUT, CURLE_RECV_ERROR, CURLE_SEND_ERROR.
36
37Since 8.8.0 libcurl clears the easy handle's saved errno before performing the
38transfer. Prior versions did not clear the saved errno, which means if a saved
39errno is retrieved it could be from a previous transfer on the same handle.
40
41# %PROTOCOLS%
42
43# EXAMPLE
44
45~~~c
46int main(void)
47{
48  CURL *curl = curl_easy_init();
49  if(curl) {
50    CURLcode res;
51    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
52    res = curl_easy_perform(curl);
53    if(res != CURLE_OK) {
54      long error;
55      res = curl_easy_getinfo(curl, CURLINFO_OS_ERRNO, &error);
56      if(!res && error) {
57        printf("Errno: %ld\n", error);
58      }
59    }
60    curl_easy_cleanup(curl);
61  }
62}
63~~~
64
65# %AVAILABILITY%
66
67# RETURN VALUE
68
69Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
70