1/* vsnprintf.c
 2 *
 3 * $Id: vsnprintf.c,v 1.3 2008/07/28 23:24:20 keithmarshall Exp $
 4 *
 5 * Provides an implementation of the "vsnprintf" function, conforming
 6 * generally to C99 and SUSv3/POSIX specifications, with extensions
 7 * to support Microsoft's non-standard format specifications.  This
 8 * is included in libmingwex.a, replacing the redirection through
 9 * libmoldnames.a, to the MSVCRT standard "_vsnprintf" function; (the
10 * standard MSVCRT function remains available, and may  be invoked
11 * directly, using this fully qualified form of its name).
12 *
13 * Written by Keith Marshall <keithmarshall@users.sourceforge.net>
14 *
15 * This is free software.  You may redistribute and/or modify it as you
16 * see fit, without restriction of copyright.
17 *
18 * This software is provided "as is", in the hope that it may be useful,
19 * but WITHOUT WARRANTY OF ANY KIND, not even any implied warranty of
20 * MERCHANTABILITY, nor of FITNESS FOR ANY PARTICULAR PURPOSE.  At no
21 * time will the author accept any form of liability for any damages,
22 * however caused, resulting from the use of this software.
23 *
24 */
25
26#include <stdio.h>
27#include <stdarg.h>
28
29#include "mingw_pformat.h"
30
31int __cdecl __vsnprintf (APICHAR *, size_t, const APICHAR *fmt, va_list) __MINGW_NOTHROW;
32int __cdecl __vsnprintf(APICHAR *buf, size_t length, const APICHAR *fmt, va_list argv )
33{
34  register int retval;
35
36  if( length == (size_t)(0) )
37  {
38#if defined(__BUILD_WIDEAPI) && defined(__BUILD_WIDEAPI_ISO)
39    /* No buffer; for wide api ISO C95+ vswprintf() function
40     * simply returns negative value as required by ISO C95+.
41     */
42    return -1;
43#else
44    /*
45     * No buffer; simply compute and return the size required,
46     * without actually emitting any data.
47     */
48    return __pformat( 0, buf, 0, fmt, argv);
49#endif
50  }
51
52  /* If we get to here, then we have a buffer...
53   * Emit data up to the limit of buffer length less one,
54   * then add the requisite NUL terminator.
55   */
56  retval = __pformat( 0, buf, --length, fmt, argv );
57  buf[retval < (int) length ? retval : (int)length] = '\0';
58
59#if defined(__BUILD_WIDEAPI) && defined(__BUILD_WIDEAPI_ISO)
60  /* For wide api ISO C95+ vswprintf() when requested length
61   * is equal or larger than buffer length, returns negative
62   * value as required by ISO C95+.
63   */
64  if( retval >= (int) length )
65    retval = -1;
66#endif
67
68  return retval;
69}
70