Blame view

ffmpeg-4.2.2/compat/msvcrt/snprintf.c 2.08 KB
aac5773f   hucm   功能基本完成,接口待打磨
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
  /*
   * C99-compatible snprintf() and vsnprintf() implementations
   * Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include <stdio.h>
  #include <stdarg.h>
  #include <limits.h>
  #include <string.h>
  
  #include "compat/va_copy.h"
  #include "libavutil/error.h"
  
  #if defined(__MINGW32__)
  #define EOVERFLOW EFBIG
  #endif
  
  int avpriv_snprintf(char *s, size_t n, const char *fmt, ...)
  {
      va_list ap;
      int ret;
  
      va_start(ap, fmt);
      ret = avpriv_vsnprintf(s, n, fmt, ap);
      va_end(ap);
  
      return ret;
  }
  
  int avpriv_vsnprintf(char *s, size_t n, const char *fmt,
                       va_list ap)
  {
      int ret;
      va_list ap_copy;
  
      if (n == 0)
          return _vscprintf(fmt, ap);
      else if (n > INT_MAX)
          return AVERROR(EOVERFLOW);
  
      /* we use n - 1 here because if the buffer is not big enough, the MS
       * runtime libraries don't add a terminating zero at the end. MSDN
       * recommends to provide _snprintf/_vsnprintf() a buffer size that
       * is one less than the actual buffer, and zero it before calling
       * _snprintf/_vsnprintf() to workaround this problem.
       * See http://msdn.microsoft.com/en-us/library/1kt27hek(v=vs.80).aspx */
      memset(s, 0, n);
      va_copy(ap_copy, ap);
      ret = _vsnprintf(s, n - 1, fmt, ap_copy);
      va_end(ap_copy);
      if (ret == -1)
          ret = _vscprintf(fmt, ap);
  
      return ret;
  }