blob: ca30f94012eead46adb2e3161e0f31149018746a [file] [log] [blame]
/* $OpenBSD: vsnprintf.c,v 1.12 2006/01/06 18:53:04 millert Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include "local.h"
int
vsnprintf(char *str, size_t n, const char *fmt, __va_list ap)
{
int ret;
char dummy;
FILE f;
struct __sfileext fext;
_FILEEXT_SETUP(&f, &fext);
/* While snprintf(3) specifies size_t stdio uses an int internally */
if (n > INT_MAX)
n = INT_MAX;
/* Stdio internals do not deal correctly with zero length buffer */
if (n == 0) {
str = &dummy;
n = 1;
}
f._file = -1;
f._flags = __SWR | __SSTR;
f._bf._base = f._p = (unsigned char *)str;
f._bf._size = f._w = n - 1;
ret = __vfprintf(&f, fmt, ap);
*f._p = '\0';
return (ret);
}