lib/libc/stdio/vsnprintf.c

   1 /*      $NetBSD: vsnprintf.c,v 1.27 2013/05/17 12:55:57 joerg Exp $     */
   2
   3 /*-
   4  * Copyright (c) 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Chris Torek.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/cdefs.h>
  36 #if defined(LIBC_SCCS) && !defined(lint)
  37 #if 0
  38 static char sccsid[] = "@(#)vsnprintf.c 8.1 (Berkeley) 6/4/93";
  39 #else
  40 __RCSID("$NetBSD: vsnprintf.c,v 1.27 2013/05/17 12:55:57 joerg Exp $");
  41 #endif
  42 #endif /* LIBC_SCCS and not lint */
  43
  44 #include "namespace.h"
  45
  46 #include <assert.h>
  47 #include <errno.h>
  48 #include <locale.h>
  49 #include <stdio.h>
  50 #include "reentrant.h"
  51 #include "setlocale_local.h"
  52 #include "local.h"
  53
  54 #if defined(_FORTIFY_SOURCE) && !defined(__lint__)
  55 #undef vsnprintf
  56 #define vsnprintf _vsnprintf
  57 #undef snprintf
  58 #define snprintf _snprintf
  59 #endif
  60
  61 #ifdef __weak_alias
  62 __weak_alias(vsnprintf,_vsnprintf)
  63 __weak_alias(vsnprintf_l,_vsnprintf_l)
  64 __weak_alias(snprintf,_snprintf)
  65 __weak_alias(snprintf_l,_snprintf_l)
  66 #endif
  67
  68 int
  69 vsnprintf_l(char *str, size_t n, locale_t loc, const char *fmt, va_list ap)
  70 {
  71         int ret;
  72         FILE f;
  73         struct __sfileext fext;
  74         unsigned char dummy[1];
  75
  76         _DIAGASSERT(n == 0 || str != NULL);
  77         _DIAGASSERT(fmt != NULL);
  78
  79         if ((int)n < 0) {
  80                 errno = EINVAL;
  81                 return -1;
  82         }
  83
  84         _FILEEXT_SETUP(&f, &fext);
  85         f._file = -1;
  86         f._flags = __SWR | __SSTR;
  87         if (n == 0) {
  88                 f._bf._base = f._p = dummy;
  89                 f._bf._size = f._w = 0;
  90         } else {
  91                 f._bf._base = f._p = (unsigned char *)str;
  92                 _DIAGASSERT(__type_fit(int, n - 1));
  93                 f._bf._size = f._w = (int)(n - 1);
  94         }
  95         ret = __vfprintf_unlocked_l(&f, loc, fmt, ap);
  96         *f._p = 0;
  97         return ret;
  98 }
  99
 100 int
 101 vsnprintf(char *str, size_t n, const char *fmt, va_list ap)
 102 {
 103         return vsnprintf_l(str, n, _current_locale(), fmt, ap);
 104 }
 105
 106 int
 107 snprintf(char *str, size_t n, const char *fmt, ...)
 108 {
 109         va_list ap;
 110         int ret;
 111
 112         va_start(ap, fmt);
 113         ret = vsnprintf(str, n, fmt, ap);
 114         va_end(ap);
 115         return ret;
 116 }
 117
 118 int
 119 snprintf_l(char *str, size_t n, locale_t loc, const char *fmt, ...)
 120 {
 121         va_list ap;
 122         int ret;
 123
 124         va_start(ap, fmt);
 125         ret = vsnprintf_l(str, n, loc, fmt, ap);
 126         va_end(ap);
 127         return ret;
 128 }