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vasprintf.c revision 1.5 
      1 /*	$NetBSD: vasprintf.c,v 1.5 1999/09/16 11:45:31 lukem Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1997 Todd C. Miller <Todd.Miller (at) courtesan.com>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. The name of the author may not be used to endorse or promote products
     16  *    derived from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
     19  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
     20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
     21  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     24  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     26  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     27  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #include <sys/cdefs.h>
     31 #if defined(LIBC_SCCS) && !defined(lint)
     32 __RCSID("$NetBSD: vasprintf.c,v 1.5 1999/09/16 11:45:31 lukem Exp $");
     33 #endif /* LIBC_SCCS and not lint */
     34 
     35 #include <assert.h>
     36 #include <errno.h>
     37 #include <stdio.h>
     38 #include <stdlib.h>
     39 
     40 int
     41 vasprintf(str, fmt, ap)
     42 	char **str;
     43 	const char *fmt;
     44 	_BSD_VA_LIST_ ap;
     45 {
     46 	int ret;
     47 	FILE f;
     48 	unsigned char *_base;
     49 
     50 	_DIAGASSERT(str != NULL);
     51 	_DIAGASSERT(fmt != NULL);
     52 #ifdef _DIAGNOSTIC
     53 	if (str == NULL || fmt == NULL) {
     54 		errno = EFAULT;
     55 		return (-1);
     56 	}
     57 #endif
     58 
     59 	f._flags = __SWR | __SSTR | __SALC;
     60 	f._bf._base = f._p = (unsigned char *)malloc(128);
     61 	if (f._bf._base == NULL)
     62 		goto err;
     63 	f._bf._size = f._w = 127;		/* Leave room for the NUL */
     64 	ret = vfprintf(&f, fmt, ap);
     65 	if (ret == -1)
     66 		goto err;
     67 	*f._p = '\0';
     68 	_base = realloc(f._bf._base, (size_t)(ret + 1));
     69 	if (_base == NULL)
     70 		goto err;
     71 	*str = (char *)_base;
     72 	return (ret);
     73 
     74 err:
     75 	if (f._bf._base)
     76 		free(f._bf._base);
     77 	*str = NULL;
     78 	errno = ENOMEM;
     79 	return (-1);
     80 }
     81