bsd-asprintf.c revision 323121 
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
43vasprintf(char **str, const char *fmt, va_list ap)
44{
45	int ret = -1;
46	va_list ap2;
47	char *string, *newstr;
48	size_t len;
49
50	VA_COPY(ap2, ap);
51	if ((string = malloc(INIT_SZ)) == NULL)
52		goto fail;
53
54	ret = vsnprintf(string, INIT_SZ, fmt, ap2);
55	if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */
56		*str = string;
57	} else if (ret == INT_MAX || ret < 0) { /* Bad length */
58		free(string);
59		goto fail;
60	} else {	/* bigger than initial, realloc allowing for nul */
61		len = (size_t)ret + 1;
62		if ((newstr = realloc(string, len)) == NULL) {
63			free(string);
64			goto fail;
65		} else {
66			va_end(ap2);
67			VA_COPY(ap2, ap);
68			ret = vsnprintf(newstr, len, fmt, ap2);
69			if (ret >= 0 && (size_t)ret < len) {
70				*str = newstr;
71			} else { /* failed with realloc'ed string, give up */
72				free(newstr);
73				goto fail;
74			}
75		}
76	}
77	va_end(ap2);
78	return (ret);
79
80fail:
81	*str = NULL;
82	errno = ENOMEM;
83	va_end(ap2);
84	return (-1);
85}
86#endif
87
88#ifndef HAVE_ASPRINTF
89int asprintf(char **str, const char *fmt, ...)
90{
91	va_list ap;
92	int ret;
93
94	*str = NULL;
95	va_start(ap, fmt);
96	ret = vasprintf(str, fmt, ap);
97	va_end(ap);
98
99	return ret;
100}
101#endif
102