1 /* vsprintf with automatic memory allocation.
2 Copyright (C) 2002-2004, 2007-2011 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 General Public License as published by
6 the Free Software Foundation; either version 3, or (at your option)
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.
14 You should have received a copy of the GNU General Public License along
15 with this program; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
27 /* The __attribute__ feature is available in gcc versions 2.5 and later.
28 The __-protected variants of the attributes 'format' and 'printf' are
29 accepted by gcc versions 2.6.4 (effectively 2.7) and later.
30 We enable _GL_ATTRIBUTE_FORMAT only if these are supported too, because
31 gnulib and libintl do '#define printf __printf__' when they override
32 the 'printf' function. */
33 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
34 # define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec))
36 # define _GL_ATTRIBUTE_FORMAT(spec) /* empty */
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 #if REPLACE_VASNPRINTF
68 # define asnprintf rpl_asnprintf
69 # define vasnprintf rpl_vasnprintf
71 extern char * asnprintf (char *resultbuf, size_t *lengthp, const char *format, ...)
72 _GL_ATTRIBUTE_FORMAT ((__printf__, 3, 4));
73 extern char * vasnprintf (char *resultbuf, size_t *lengthp, const char *format, va_list args)
74 _GL_ATTRIBUTE_FORMAT ((__printf__, 3, 0));
80 #endif /* _VASNPRINTF_H */