lib/vasprintf.c

   1 /* Like vsprintf but provides a pointer to malloc'd storage, which must
   2    be freed by the caller.
   3    Copyright (C) 1994, 2003 Free Software Foundation, Inc.
   4    Copyright (C) 2002 Simon Josefsson
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 #include "internal.h"
  21
  22 static int
  23 int_vasprintf (char **result, char *format, va_list * args)
  24 {
  25   char *p = format;
  26   /* Add one to make sure that it is never zero, which might cause malloc
  27      to return NULL.  */
  28   int total_width = strlen (format) + 1;
  29   va_list ap;
  30
  31   memcpy (&ap, args, sizeof (va_list));
  32
  33   while (*p != '\0')
  34     {
  35       if (*p++ == '%')
  36         {
  37           while (strchr ("-+ #0", *p))
  38             ++p;
  39           if (*p == '*')
  40             {
  41               ++p;
  42               total_width += abs (va_arg (ap, int));
  43             }
  44           else
  45             total_width += strtoul (p, &p, 10);
  46           if (*p == '.')
  47             {
  48               ++p;
  49               if (*p == '*')
  50                 {
  51                   ++p;
  52                   total_width += abs (va_arg (ap, int));
  53                 }
  54               else
  55                 total_width += strtoul (p, (char **) &p, 10);
  56             }
  57           while (strchr ("hlL", *p))
  58             ++p;
  59           /* Should be big enough for any format specifier except %s.  */
  60           total_width += 30;
  61           switch (*p)
  62             {
  63             case 'd':
  64             case 'i':
  65             case 'o':
  66             case 'u':
  67             case 'x':
  68             case 'X':
  69             case 'c':
  70               (void) va_arg (ap, int);
  71               break;
  72             case 'f':
  73             case 'e':
  74             case 'E':
  75             case 'g':
  76             case 'G':
  77               (void) va_arg (ap, double);
  78               break;
  79             case 's':
  80               total_width += strlen (va_arg (ap, char *));
  81               break;
  82             case 'p':
  83             case 'n':
  84               (void) va_arg (ap, char *);
  85               break;
  86             }
  87         }
  88     }
  89   *result = malloc (total_width);
  90   if (*result != NULL)
  91     return vsprintf (*result, format, *args);
  92   else
  93     return 0;
  94 }
  95
  96 static int
  97 _shishi_vasprintf (char **result, char *format, va_list args)
  98 {
  99   return int_vasprintf (result, format, &args);
 100 }
 101
 102 int
 103 shishi_asprintf (char **result, char *format, ...)
 104 {
 105   va_list args;
 106   int done;
 107
 108   va_start (args, format);
 109   done = _shishi_vasprintf (result, format, args);
 110   va_end (args);
 111
 112   return done;
 113 }