1 /* sprintf_alloc.c -- like sprintf with memory allocation
5 Copyright (C) 2001 University of Southern California
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
21 #include "sprintf_alloc.h"
22 #include "libbb/libbb.h"
24 int sprintf_alloc(char **str, const char *fmt, ...)
30 fprintf(stderr, "Null string pointer passed to sprintf_alloc\n");
34 fprintf(stderr, "Null fmt string passed to sprintf_alloc\n");
38 /* On x86_64 systems, any strings over 100 were segfaulting.
39 It seems that the ap needs to be reinitalized before every
40 use of the v*printf() functions. I pulled the functionality out
41 of vsprintf_alloc and combined it all here instead.
45 /* ripped more or less straight out of PRINTF(3) */
47 *str = xcalloc(1, size);
51 n = vsnprintf (*str, size, fmt, ap);
53 /* If that worked, return the size. */
54 if (n > -1 && n < size)
56 /* Else try again with more space. */
57 if (n > -1) /* glibc 2.1 */
58 size = n+1; /* precisely what is needed */
60 size *= 2; /* twice the old size */
61 *str = xrealloc(*str, size);
64 return -1; /* Just to be correct - it probably won't get here */