NetBSD/lib/libc/stdio/asprintf.c

86 lines
2.6 KiB
C

/* $NetBSD: asprintf.c,v 1.19 2012/03/15 18:22:30 christos Exp $ */
/*
* Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
* All rights reserved.
*
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``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 AUTHOR 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 <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: asprintf.c,v 1.19 2012/03/15 18:22:30 christos Exp $");
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <assert.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include "reentrant.h"
#include "local.h"
#ifdef __weak_alias
__weak_alias(asprintf, _asprintf)
#endif
int
asprintf(char **str, char const *fmt, ...)
{
int ret;
va_list ap;
FILE f;
struct __sfileext fext;
unsigned char *_base;
_DIAGASSERT(str != NULL);
_FILEEXT_SETUP(&f, &fext);
f._file = -1;
f._flags = __SWR | __SSTR | __SALC;
f._bf._base = f._p = malloc((size_t)128);
if (f._bf._base == NULL)
goto err;
f._bf._size = f._w = 127; /* Leave room for the NUL */
va_start(ap, fmt);
ret = __vfprintf_unlocked(&f, fmt, ap);
va_end(ap);
if (ret < 0)
goto err;
*f._p = '\0';
_base = realloc(f._bf._base, (size_t)ret + 1);
if (_base == NULL)
goto err;
*str = (char *)_base;
return ret;
err:
if (f._bf._base)
free(f._bf._base);
*str = NULL;
errno = ENOMEM;
return -1;
}