bsd-asprintf.c revision 323129 
1/*
2 * Copyright (c) 2004 Darren Tucker.
3 *
4 * Based originally on asprintf.c from OpenBSD:
5 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20#include "includes.h"
21
22#ifndef HAVE_VASPRINTF
23
24#include <errno.h>
25#include <stdarg.h>
26#include <stdlib.h>
27
28#define INIT_SZ	128
29
30int
31vasprintf(char **str, const char *fmt, va_list ap)
32{
33	int ret = -1;
34	va_list ap2;
35	char *string, *newstr;
36	size_t len;
37
38	VA_COPY(ap2, ap);
39	if ((string = malloc(INIT_SZ)) == NULL)
40		goto fail;
41
42	ret = vsnprintf(string, INIT_SZ, fmt, ap2);
43	if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */
44		*str = string;
45	} else if (ret == INT_MAX || ret < 0) { /* Bad length */
46		free(string);
47		goto fail;
48	} else {	/* bigger than initial, realloc allowing for nul */
49		len = (size_t)ret + 1;
50		if ((newstr = realloc(string, len)) == NULL) {
51			free(string);
52			goto fail;
53		} else {
54			va_end(ap2);
55			VA_COPY(ap2, ap);
56			ret = vsnprintf(newstr, len, fmt, ap2);
57			if (ret >= 0 && (size_t)ret < len) {
58				*str = newstr;
59			} else { /* failed with realloc'ed string, give up */
60				free(newstr);
61				goto fail;
62			}
63		}
64	}
65	va_end(ap2);
66	return (ret);
67
68fail:
69	*str = NULL;
70	errno = ENOMEM;
71	va_end(ap2);
72	return (-1);
73}
74#endif
75
76#ifndef HAVE_ASPRINTF
77int asprintf(char **str, const char *fmt, ...)
78{
79	va_list ap;
80	int ret;
81
82	*str = NULL;
83	va_start(ap, fmt);
84	ret = vasprintf(str, fmt, ap);
85	va_end(ap);
86
87	return ret;
88}
89#endif
90