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vsnprintf.c revision 1.29 
      1 /*	$NetBSD: vsnprintf.c,v 1.29 2017/01/12 18:16:52 christos 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 1.29 2017/01/12 18:16:52 christos 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 __SSP_FORTIFY_LEVEL != 0
     55 # undef vsnprintf
     56 # define vsnprintf _vsnprintf
     57 # undef snprintf
     58 # define snprintf _snprintf
     59 int      snprintf(char * __restrict, size_t, const char * __restrict, ...)
     60     __printflike(3, 4);
     61 int      vsnprintf(char * __restrict, size_t, const char * __restrict,
     62     __va_list) __printflike(3, 0);
     63 #endif
     64 
     65 #ifdef __weak_alias
     66 __weak_alias(vsnprintf,_vsnprintf)
     67 __weak_alias(vsnprintf_l,_vsnprintf_l)
     68 __weak_alias(snprintf,_snprintf)
     69 __weak_alias(snprintf_l,_snprintf_l)
     70 #endif
     71 
     72 int
     73 vsnprintf_l(char *str, size_t n, locale_t loc, const char *fmt, va_list ap)
     74 {
     75 	int ret;
     76 	FILE f;
     77 	struct __sfileext fext;
     78 	unsigned char dummy[1];
     79 
     80 	_DIAGASSERT(n == 0 || str != NULL);
     81 	_DIAGASSERT(fmt != NULL);
     82 
     83 	if (n > INT_MAX) {
     84 		errno = EOVERFLOW;
     85 		return -1;
     86 	}
     87 
     88 	_FILEEXT_SETUP(&f, &fext);
     89 	f._file = -1;
     90 	f._flags = __SWR | __SSTR;
     91 	if (n == 0) {
     92 		f._bf._base = f._p = dummy;
     93 		f._bf._size = f._w = 0;
     94 	} else {
     95 		f._bf._base = f._p = (unsigned char *)str;
     96 		_DIAGASSERT(__type_fit(int, n - 1));
     97 		f._bf._size = f._w = (int)(n - 1);
     98 	}
     99 	ret = __vfprintf_unlocked_l(&f, loc, fmt, ap);
    100 	*f._p = 0;
    101 	return ret;
    102 }
    103 
    104 int
    105 vsnprintf(char *str, size_t n, const char *fmt, va_list ap)
    106 {
    107 	return vsnprintf_l(str, n, _current_locale(), fmt, ap);
    108 }
    109 
    110 int
    111 snprintf(char *str, size_t n, const char *fmt, ...)
    112 {
    113 	va_list ap;
    114 	int ret;
    115 
    116 	va_start(ap, fmt);
    117 	ret = vsnprintf(str, n, fmt, ap);
    118 	va_end(ap);
    119 	return ret;
    120 }
    121 
    122 int
    123 snprintf_l(char *str, size_t n, locale_t loc, const char *fmt, ...)
    124 {
    125 	va_list ap;
    126 	int ret;
    127 
    128 	va_start(ap, fmt);
    129 	ret = vsnprintf_l(str, n, loc, fmt, ap);
    130 	va_end(ap);
    131 	return ret;
    132 }
    133