bsd-asprintf.c revision 181110 
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#ifndef VA_COPY
29# ifdef HAVE_VA_COPY
30#  define VA_COPY(dest, src) va_copy(dest, src)
31# else
32#  ifdef HAVE___VA_COPY
33#   define VA_COPY(dest, src) __va_copy(dest, src)
34#  else
35#   define VA_COPY(dest, src) (dest) = (src)
36#  endif
37# endif
38#endif
39
40#define INIT_SZ	128
41
42int vasprintf(char **str, const char *fmt, va_list ap)
43{
44	int ret = -1;
45	va_list ap2;
46	char *string, *newstr;
47	size_t len;
48
49	VA_COPY(ap2, ap);
50	if ((string = malloc(INIT_SZ)) == NULL)
51		goto fail;
52
53	ret = vsnprintf(string, INIT_SZ, fmt, ap2);
54	if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */
55		*str = string;
56	} else if (ret == INT_MAX) { /* shouldn't happen */
57		goto fail;
58	} else {	/* bigger than initial, realloc allowing for nul */
59		len = (size_t)ret + 1;
60		if ((newstr = realloc(string, len)) == NULL) {
61			free(string);
62			goto fail;
63		} else {
64			va_end(ap2);
65			VA_COPY(ap2, ap);
66			ret = vsnprintf(newstr, len, fmt, ap2);
67			if (ret >= 0 && (size_t)ret < len) {
68				*str = newstr;
69			} else { /* failed with realloc'ed string, give up */
70				free(newstr);
71				goto fail;
72			}
73		}
74	}
75	va_end(ap2);
76	return (ret);
77
78fail:
79	*str = NULL;
80	errno = ENOMEM;
81	va_end(ap2);
82	return (-1);
83}
84#endif
85
86#ifndef HAVE_ASPRINTF
87int asprintf(char **str, const char *fmt, ...)
88{
89	va_list ap;
90	int ret;
91
92	*str = NULL;
93	va_start(ap, fmt);
94	ret = vasprintf(str, fmt, ap);
95	va_end(ap);
96
97	return ret;
98}
99#endif
100