1/* vsprintf with automatic memory allocation. 2 Copyright (C) 2002-2004 Free Software Foundation, Inc. 3 4 This program is free software; you can redistribute it and/or modify it 5 under the terms of the GNU Library General Public License as published 6 by the Free Software Foundation; either version 2, or (at your option) 7 any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 Library General Public License for more details. 13 14 You should have received a copy of the GNU Library General Public 15 License along with this program; if not, write to the Free Software 16 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 17 USA. */ 18 19#ifndef _VASNPRINTF_H 20#define _VASNPRINTF_H 21 22/* Get va_list. */ 23#include <stdarg.h> 24 25/* Get size_t. */ 26#include <stddef.h> 27 28#ifndef __attribute__ 29/* This feature is available in gcc versions 2.5 and later. */ 30# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) || __STRICT_ANSI__ 31# define __attribute__(Spec) /* empty */ 32# endif 33/* The __-protected variants of `format' and `printf' attributes 34 are accepted by gcc versions 2.6.4 (effectively 2.7) and later. */ 35# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7) 36# define __format__ format 37# define __printf__ printf 38# endif 39#endif 40 41#ifdef __cplusplus 42extern "C" { 43#endif 44 45/* Write formatted output to a string dynamically allocated with malloc(). 46 You can pass a preallocated buffer for the result in RESULTBUF and its 47 size in *LENGTHP; otherwise you pass RESULTBUF = NULL. 48 If successful, return the address of the string (this may be = RESULTBUF 49 if no dynamic memory allocation was necessary) and set *LENGTHP to the 50 number of resulting bytes, excluding the trailing NUL. Upon error, set 51 errno and return NULL. 52 53 When dynamic memory allocation occurs, the preallocated buffer is left 54 alone (with possibly modified contents). This makes it possible to use 55 a statically allocated or stack-allocated buffer, like this: 56 57 char buf[100]; 58 size_t len = sizeof (buf); 59 char *output = vasnprintf (buf, &len, format, args); 60 if (output == NULL) 61 ... error handling ...; 62 else 63 { 64 ... use the output string ...; 65 if (output != buf) 66 free (output); 67 } 68 */ 69extern char * asnprintf (char *resultbuf, size_t *lengthp, const char *format, ...) 70 __attribute__ ((__format__ (__printf__, 3, 4))); 71extern char * vasnprintf (char *resultbuf, size_t *lengthp, const char *format, va_list args) 72 __attribute__ ((__format__ (__printf__, 3, 0))); 73 74#ifdef __cplusplus 75} 76#endif 77 78#endif /* _VASNPRINTF_H */ 79