1 /* vsprintf with automatic memory allocation.
2 Copyright (C) 2002-2004, 2012, 2015 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU Lesser General Public License as published by
6 the Free Software Foundation; either version 2.1 of the License, or
7 (at your option) any later version.
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 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 /* This feature is available in gcc versions 2.5 and later. */
28 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) || __STRICT_ANSI__
29 # define __attribute__(Spec) /* empty */
31 /* The __-protected variants of 'format' and 'printf' attributes
32 are accepted by gcc versions 2.6.4 (effectively 2.7) and later. */
33 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
34 # define __format__ format
35 # define __printf__ printf
43 /* Write formatted output to a string dynamically allocated with malloc().
44 You can pass a preallocated buffer for the result in RESULTBUF and its
45 size in *LENGTHP; otherwise you pass RESULTBUF = NULL.
46 If successful, return the address of the string (this may be = RESULTBUF
47 if no dynamic memory allocation was necessary) and set *LENGTHP to the
48 number of resulting bytes, excluding the trailing NUL. Upon error, set
49 errno and return NULL.
51 When dynamic memory allocation occurs, the preallocated buffer is left
52 alone (with possibly modified contents). This makes it possible to use
53 a statically allocated or stack-allocated buffer, like this:
56 size_t len = sizeof (buf);
57 char *output = vasnprintf (buf, &len, format, args);
59 ... error handling ...;
62 ... use the output string ...;
67 extern char * asnprintf (char *resultbuf, size_t *lengthp, const char *format, ...)
68 __attribute__ ((__format__ (__printf__, 3, 4)));
69 extern char * vasnprintf (char *resultbuf, size_t *lengthp, const char *format, va_list args)
70 __attribute__ ((__format__ (__printf__, 3, 0)));
76 #endif /* _VASNPRINTF_H */