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/* vsprintf with automatic memory allocation.
Copyright (C) 2002-2004, 2007-2010 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
/* Get va_list. */
#include <stdarg.h>
/* Get size_t. */
#include <stddef.h>
#ifndef __attribute__
/* The __attribute__ feature is available in gcc versions 2.5 and later.
The __-protected variants of the attributes 'format' and 'printf' are
accepted by gcc versions 2.6.4 (effectively 2.7) and later.
We enable __attribute__ only if these are supported too, because
gnulib and libintl do '#define printf __printf__' when they override
the 'printf' function. */
# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
# define __attribute__(Spec) /* empty */
# endif
#ifdef __cplusplus
extern "C" {
/* Write formatted output to a string dynamically allocated with malloc().
You can pass a preallocated buffer for the result in RESULTBUF and its
size in *LENGTHP; otherwise you pass RESULTBUF = NULL.
If successful, return the address of the string (this may be = RESULTBUF
if no dynamic memory allocation was necessary) and set *LENGTHP to the
number of resulting bytes, excluding the trailing NUL. Upon error, set
errno and return NULL.
When dynamic memory allocation occurs, the preallocated buffer is left
alone (with possibly modified contents). This makes it possible to use
a statically allocated or stack-allocated buffer, like this:
char buf[100];
size_t len = sizeof (buf);
char *output = vasnprintf (buf, &len, format, args);
if (output == NULL)
... error handling ...;
... use the output string ...;
if (output != buf)
free (output);
# define asnprintf rpl_asnprintf
# define vasnprintf rpl_vasnprintf
extern char * asnprintf (char *resultbuf, size_t *lengthp, const char *format, ...)
__attribute__ ((__format__ (__printf__, 3, 4)));
extern char * vasnprintf (char *resultbuf, size_t *lengthp, const char *format, va_list args)
__attribute__ ((__format__ (__printf__, 3, 0)));
#ifdef __cplusplus
#endif /* _VASNPRINTF_H */