intl/vasnprintf.h

   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
  42 extern "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   */
  69 extern char * asnprintf (char *resultbuf, size_t *lengthp, const char *format, ...)
  70        __attribute__ ((__format__ (__printf__, 3, 4)));
  71 extern 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 */