xref: /freebsd-src/contrib/mandoc/compat_vasprintf.c (revision 61d06d6bd19dafe8ea971dd43e8328fa1b473456)
1*61d06d6bSBaptiste Daroussin #include "config.h"
2*61d06d6bSBaptiste Daroussin 
3*61d06d6bSBaptiste Daroussin #if HAVE_VASPRINTF
4*61d06d6bSBaptiste Daroussin 
5*61d06d6bSBaptiste Daroussin int dummy;
6*61d06d6bSBaptiste Daroussin 
7*61d06d6bSBaptiste Daroussin #else
8*61d06d6bSBaptiste Daroussin 
9*61d06d6bSBaptiste Daroussin /*	$Id: compat_vasprintf.c,v 1.3 2015/10/06 18:32:19 schwarze Exp $	*/
10*61d06d6bSBaptiste Daroussin /*
11*61d06d6bSBaptiste Daroussin  * Copyright (c) 2015 Ingo Schwarze <schwarze@openbsd.org>
12*61d06d6bSBaptiste Daroussin  *
13*61d06d6bSBaptiste Daroussin  * Permission to use, copy, modify, and distribute this software for any
14*61d06d6bSBaptiste Daroussin  * purpose with or without fee is hereby granted, provided that the above
15*61d06d6bSBaptiste Daroussin  * copyright notice and this permission notice appear in all copies.
16*61d06d6bSBaptiste Daroussin  *
17*61d06d6bSBaptiste Daroussin  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
18*61d06d6bSBaptiste Daroussin  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
19*61d06d6bSBaptiste Daroussin  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
20*61d06d6bSBaptiste Daroussin  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
21*61d06d6bSBaptiste Daroussin  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
22*61d06d6bSBaptiste Daroussin  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
23*61d06d6bSBaptiste Daroussin  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
24*61d06d6bSBaptiste Daroussin  *
25*61d06d6bSBaptiste Daroussin  * This fallback implementation is not efficient:
26*61d06d6bSBaptiste Daroussin  * It does the formatting twice.
27*61d06d6bSBaptiste Daroussin  * Short of fiddling with the unknown internals of the system's
28*61d06d6bSBaptiste Daroussin  * printf(3) or completely reimplementing printf(3), i can't think
29*61d06d6bSBaptiste Daroussin  * of another portable solution.
30*61d06d6bSBaptiste Daroussin  */
31*61d06d6bSBaptiste Daroussin 
32*61d06d6bSBaptiste Daroussin #include <stdarg.h>
33*61d06d6bSBaptiste Daroussin #include <stdio.h>
34*61d06d6bSBaptiste Daroussin #include <stdlib.h>
35*61d06d6bSBaptiste Daroussin 
36*61d06d6bSBaptiste Daroussin int
37*61d06d6bSBaptiste Daroussin vasprintf(char **ret, const char *format, va_list ap)
38*61d06d6bSBaptiste Daroussin {
39*61d06d6bSBaptiste Daroussin 	char	 buf[2];
40*61d06d6bSBaptiste Daroussin 	va_list	 ap2;
41*61d06d6bSBaptiste Daroussin 	int	 sz;
42*61d06d6bSBaptiste Daroussin 
43*61d06d6bSBaptiste Daroussin 	va_copy(ap2, ap);
44*61d06d6bSBaptiste Daroussin 	sz = vsnprintf(buf, sizeof(buf), format, ap2);
45*61d06d6bSBaptiste Daroussin 	va_end(ap2);
46*61d06d6bSBaptiste Daroussin 
47*61d06d6bSBaptiste Daroussin 	if (sz != -1 && (*ret = malloc(sz + 1)) != NULL) {
48*61d06d6bSBaptiste Daroussin 		if (vsnprintf(*ret, sz + 1, format, ap) == sz)
49*61d06d6bSBaptiste Daroussin 			return sz;
50*61d06d6bSBaptiste Daroussin 		free(*ret);
51*61d06d6bSBaptiste Daroussin 	}
52*61d06d6bSBaptiste Daroussin 	*ret = NULL;
53*61d06d6bSBaptiste Daroussin 	return -1;
54*61d06d6bSBaptiste Daroussin }
55*61d06d6bSBaptiste Daroussin 
56*61d06d6bSBaptiste Daroussin #endif
57