lib/utils.c

   1 /* Dia -- an diagram creation/manipulation program
   2  * Copyright (C) 1998 Alexander Larsson
   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 2 of the License, or
   7  * (at your option) 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
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17  */
  18
  19 /* This file contains some code from glib.
  20   Here is the copyright notice:
  21
  22  * GLIB - Library of useful routines for C programming
  23  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
  24  */
  25
  26
  27 #include <config.h>
  28
  29 #include <stdlib.h>
  30 #include <stdio.h>
  31 #include <string.h>
  32
  33 #include <glib.h>
  34
  35 #include "utils.h"
  36
  37 int
  38 nearest_pow (int num)
  39 {
  40   int n = 1;
  41
  42   while (n < num)
  43     n <<= 1;
  44
  45   return n;
  46 }
  47
  48 int
  49 format_string_length_upper_bound (const char* fmt, va_list *args)
  50 { /* UTF8 ? */
  51   int len = 0;
  52   int short_int;
  53   int long_int;
  54   int done;
  55   char *tmp;
  56
  57   while (*fmt)
  58     {
  59       char c = *fmt++;
  60
  61       short_int = FALSE;
  62       long_int = FALSE;
  63
  64       if (c == '%')
  65         {
  66           done = FALSE;
  67           while (*fmt && !done)
  68             {
  69               switch (*fmt++)
  70                 {
  71                 case '*':
  72                   len += va_arg(*args, int);
  73                   break;
  74                 case '1':
  75                 case '2':
  76                 case '3':
  77                 case '4':
  78                 case '5':
  79                 case '6':
  80                 case '7':
  81                 case '8':
  82                 case '9':
  83                   fmt -= 1;
  84                   len += strtol (fmt, (char **)&fmt, 10);
  85                   break;
  86                 case 'h':
  87                   short_int = TRUE;
  88                   break;
  89                 case 'l':
  90                   long_int = TRUE;
  91                   break;
  92
  93                   /* I ignore 'q' and 'L', they're not portable anyway. */
  94
  95                 case 's':
  96                   tmp = va_arg(*args, char *);
  97                   if(tmp)
  98                     len += strlen (tmp);
  99                   else
 100                     len += strlen ("(null)");
 101                   done = TRUE;
 102                   break;
 103                 case 'd':
 104                 case 'i':
 105                 case 'o':
 106                 case 'u':
 107                 case 'x':
 108                 case 'X':
 109                   if (long_int)
 110                     (void)va_arg (*args, long);
 111                   else if (short_int)
 112                     (void)va_arg (*args, int);
 113                   else
 114                     (void)va_arg (*args, int);
 115                   len += 32;
 116                   done = TRUE;
 117                   break;
 118                 case 'D':
 119                 case 'O':
 120                 case 'U':
 121                   (void)va_arg (*args, long);
 122                   len += 32;
 123                   done = TRUE;
 124                   break;
 125                 case 'e':
 126                 case 'E':
 127                 case 'f':
 128                 case 'g':
 129                   (void)va_arg (*args, double);
 130                   len += 32;
 131                   done = TRUE;
 132                   break;
 133                 case 'c':
 134                   (void)va_arg (*args, int);
 135                   len += 1;
 136                   done = TRUE;
 137                   break;
 138                 case 'p':
 139                 case 'n':
 140                   (void)va_arg (*args, void*);
 141                   len += 32;
 142                   done = TRUE;
 143                   break;
 144                 case '%':
 145                   len += 1;
 146                   done = TRUE;
 147                   break;
 148                 default:
 149                   break;
 150                 }
 151             }
 152         }
 153       else
 154         len += 1;
 155     }
 156
 157   return len;
 158 }
 159
 160 #ifndef HAVE_SNPRINTF
 161 int
 162 snprintf ( char *str, size_t n, const char *format, ... )
 163 {
 164   static char *buf = NULL;
 165   static int alloc = 0;
 166   int len;
 167   va_list args, args2;
 168
 169   va_start (args, format);
 170   len = format_string_length_upper_bound (format, &args);
 171   va_end (args);
 172
 173   if (len >= alloc) {
 174       if (buf)
 175         g_free (buf);
 176
 177       alloc = nearest_pow (MAX(len + 1, 1024));
 178
 179       buf = g_new (char, alloc);
 180   }
 181
 182   va_start (args2, format);
 183   vsprintf (buf, format, args2);
 184   va_end (args2);
 185
 186   strncpy(str, buf, n);
 187   str[n-1] = 0;
 188
 189   return (len >= n)?-1:strlen(str);
 190 }
 191 #endif
 192
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