Blame view

3rdparty/curl/share/man/man3/CURLOPT_ERRORBUFFER.3 3.42 KB
a86c63ca   Hu Chunming   提交三方库文件
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
  .\" **************************************************************************
  .\" *                                  _   _ ____  _
  .\" *  Project                     ___| | | |  _ \| |
  .\" *                             / __| | | | |_) | |
  .\" *                            | (__| |_| |  _ <| |___
  .\" *                             \___|\___/|_| \_\_____|
  .\" *
  .\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
  .\" *
  .\" * This software is licensed as described in the file COPYING, which
  .\" * you should have received as part of this distribution. The terms
  .\" * are also available at https://curl.se/docs/copyright.html.
  .\" *
  .\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
  .\" * copies of the Software, and permit persons to whom the Software is
  .\" * furnished to do so, under the terms of the COPYING file.
  .\" *
  .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  .\" * KIND, either express or implied.
  .\" *
  .\" **************************************************************************
  .\"
  .TH CURLOPT_ERRORBUFFER 3 "November 04, 2020" "libcurl 7.77.0" "curl_easy_setopt options"
  
  .SH NAME
  CURLOPT_ERRORBUFFER \- set error buffer for error messages
  .SH SYNOPSIS
  #include <curl/curl.h>
  
  CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ERRORBUFFER, char *buf);
  .SH DESCRIPTION
  Pass a char * to a buffer that libcurl \fBmay\fP store human readable error
  messages on failures or problems. This may be more helpful than just the
  return code from \fIcurl_easy_perform(3)\fP and related functions. The buffer
  \fBmust be at least CURL_ERROR_SIZE bytes big\fP.
  
  You must keep the associated buffer available until libcurl no longer needs
  it. Failing to do so will cause very odd behavior or even crashes. libcurl
  will need it until you call \fIcurl_easy_cleanup(3)\fP or you set the same
  option again to use a different pointer.
  
  Do not rely on the contents of the buffer unless an error code was returned.
  Since 7.60.0 libcurl will initialize the contents of the error buffer to an
  empty string before performing the transfer. For earlier versions if an error
  code was returned but there was no error detail then the buffer is untouched.
  
  Consider \fICURLOPT_VERBOSE(3)\fP and \fICURLOPT_DEBUGFUNCTION(3)\fP to better
  debug and trace why errors happen.
  .SH DEFAULT
  NULL
  .SH PROTOCOLS
  All
  .SH EXAMPLE
  .nf
  curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    char errbuf[CURL_ERROR_SIZE];
  
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
  
    /* provide a buffer to store errors in */
    curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errbuf);
  
    /* set the error buffer as empty before performing a request */
    errbuf[0] = 0;
  
    /* perform the request */
    res = curl_easy_perform(curl);
  
    /* if the request did not complete correctly, show the error
    information. if no detailed error information was written to errbuf
    show the more generic information from curl_easy_strerror instead.
    */
    if(res != CURLE_OK) {
      size_t len = strlen(errbuf);
      fprintf(stderr, "\\nlibcurl: (%d) ", res);
      if(len)
        fprintf(stderr, "%s%s", errbuf,
                ((errbuf[len - 1] != '\\n') ? "\\n" : ""));
      else
        fprintf(stderr, "%s\\n", curl_easy_strerror(res));
    }
  }
  .fi
  .SH AVAILABILITY
  Always
  .SH RETURN VALUE
  Returns CURLE_OK
  .SH "SEE ALSO"
  .BR CURLOPT_DEBUGFUNCTION "(3), " CURLOPT_VERBOSE "(3), "
  .BR curl_easy_strerror "(3), " curl_multi_strerror "(3), "
  .BR curl_share_strerror "(3) "