1 /* vsprintf with automatic memory allocation. 2 Copyright (C) 2002-2004, 2007-2012 Free Software Foundation, Inc. 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 3, 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 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License along 15 with this program; if not, see <http://www.gnu.org/licenses/>. */ 16 17 #ifndef _VASNPRINTF_H 18 #define _VASNPRINTF_H 19 20 /* Get va_list. */ 21 #include <stdarg.h> 22 23 /* Get size_t. */ 24 #include <stddef.h> 25 26 /* The __attribute__ feature is available in gcc versions 2.5 and later. 27 The __-protected variants of the attributes 'format' and 'printf' are 28 accepted by gcc versions 2.6.4 (effectively 2.7) and later. 29 We enable _GL_ATTRIBUTE_FORMAT only if these are supported too, because 30 gnulib and libintl do '#define printf __printf__' when they override 31 the 'printf' function. */ 32 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7) 33 # define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec)) 34 #else 35 # define _GL_ATTRIBUTE_FORMAT(spec) /* empty */ 36 #endif 37 38 #ifdef __cplusplus 39 extern "C" { 40 #endif 41 42 /* Write formatted output to a string dynamically allocated with malloc(). 43 You can pass a preallocated buffer for the result in RESULTBUF and its 44 size in *LENGTHP; otherwise you pass RESULTBUF = NULL. 45 If successful, return the address of the string (this may be = RESULTBUF 46 if no dynamic memory allocation was necessary) and set *LENGTHP to the 47 number of resulting bytes, excluding the trailing NUL. Upon error, set 48 errno and return NULL. 49 50 When dynamic memory allocation occurs, the preallocated buffer is left 51 alone (with possibly modified contents). This makes it possible to use 52 a statically allocated or stack-allocated buffer, like this: 53 54 char buf[100]; 55 size_t len = sizeof (buf); 56 char *output = vasnprintf (buf, &len, format, args); 57 if (output == NULL) 58 ... error handling ...; 59 else 60 { 61 ... use the output string ...; 62 if (output != buf) 63 free (output); 64 } 65 */ 66 #if REPLACE_VASNPRINTF 67 # define asnprintf rpl_asnprintf 68 # define vasnprintf rpl_vasnprintf 69 #endif 70 extern char * asnprintf (char *resultbuf, size_t *lengthp, const char *format, ...) 71 _GL_ATTRIBUTE_FORMAT ((__printf__, 3, 4)); 72 extern char * vasnprintf (char *resultbuf, size_t *lengthp, const char *format, va_list args) 73 _GL_ATTRIBUTE_FORMAT ((__printf__, 3, 0)); 74 75 #ifdef __cplusplus 76 } 77 #endif 78 79 #endif /* _VASNPRINTF_H */ 80