1 /* sprintf_alloc.c -- like sprintf with memory allocation
2
3 Copyright (C) 2010 Ubiq Technologies <graham.gower@gmail.com>
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
8 any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14 */
15
16 #include <stdarg.h>
17
18 #include "sprintf_alloc.h"
19 #include "libbb/libbb.h"
20
sprintf_alloc(char ** str,const char * fmt,...)21 void sprintf_alloc(char **str, const char *fmt, ...)
22 {
23 va_list ap;
24 int n;
25 unsigned int size = 0;
26
27 *str = NULL;
28
29 for (;;) {
30 va_start(ap, fmt);
31 n = vsnprintf(*str, size, fmt, ap);
32 va_end(ap);
33
34 if (n < 0) {
35 fprintf(stderr, "%s: encountered an output or encoding"
36 " error during vsnprintf.\n", __FUNCTION__);
37 exit(EXIT_FAILURE);
38 }
39
40 if (n < size)
41 break;
42
43 /* Truncated, try again with more space. */
44 size = n + 1;
45 *str = xrealloc(*str, size);
46 }
47 }
48