lib/xstrtol.c

   1 /* A more useful interface to strtol.
   2    Copyright 1995, 1996, 1998, 1999 Free Software Foundation, Inc.
   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, 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
  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 Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Written by Jim Meyering. */
  19
  20 #if HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #ifndef __strtol
  25 # define __strtol strtol
  26 # define __strtol_t long int
  27 # define __xstrtol xstrtol
  28 #endif
  29
  30 /* Some pre-ANSI implementations (e.g. SunOS 4)
  31    need stderr defined if assertion checking is enabled.  */
  32 #include <stdio.h>
  33
  34 #if STDC_HEADERS
  35 # include <stdlib.h>
  36 #endif
  37
  38 #if HAVE_STRING_H
  39 # include <string.h>
  40 #else
  41 # include <strings.h>
  42 # ifndef strchr
  43 #  define strchr index
  44 # endif
  45 #endif
  46
  47 #include <assert.h>
  48 #include <ctype.h>
  49
  50 #include <errno.h>
  51 #ifndef errno
  52 extern int errno;
  53 #endif
  54
  55 #if HAVE_LIMITS_H
  56 # include <limits.h>
  57 #endif
  58
  59 #ifndef CHAR_BIT
  60 # define CHAR_BIT 8
  61 #endif
  62
  63 /* The extra casts work around common compiler bugs.  */
  64 #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
  65 /* The outer cast is needed to work around a bug in Cray C 5.0.3.0.
  66    It is necessary at least when t == time_t.  */
  67 #define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \
  68                               ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0))
  69 #define TYPE_MAXIMUM(t) (~ (t) 0 - TYPE_MINIMUM (t))
  70
  71 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
  72 # define IN_CTYPE_DOMAIN(c) 1
  73 #else
  74 # define IN_CTYPE_DOMAIN(c) isascii(c)
  75 #endif
  76
  77 #define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))
  78
  79 #include "xstrtol.h"
  80
  81 __strtol_t __strtol ();
  82
  83 static int
  84 bkm_scale (__strtol_t *x, int scale_factor)
  85 {
  86   __strtol_t product = *x * scale_factor;
  87   if (*x != product / scale_factor)
  88     return 1;
  89   *x = product;
  90   return 0;
  91 }
  92
  93 static int
  94 bkm_scale_by_power (__strtol_t *x, int base, int power)
  95 {
  96   while (power--)
  97     if (bkm_scale (x, base))
  98       return 1;
  99
 100   return 0;
 101 }
 102
 103 /* FIXME: comment.  */
 104
 105 strtol_error
 106 __xstrtol (const char *s, char **ptr, int strtol_base,
 107            __strtol_t *val, const char *valid_suffixes)
 108 {
 109   char *t_ptr;
 110   char **p;
 111   __strtol_t tmp;
 112
 113   assert (0 <= strtol_base && strtol_base <= 36);
 114
 115   p = (ptr ? ptr : &t_ptr);
 116
 117   if (! TYPE_SIGNED (__strtol_t))
 118     {
 119       const char *q = s;
 120       while (ISSPACE ((unsigned char) *q))
 121         ++q;
 122       if (*q == '-')
 123         return LONGINT_INVALID;
 124     }
 125
 126   errno = 0;
 127   tmp = __strtol (s, p, strtol_base);
 128   if (errno != 0)
 129     return LONGINT_OVERFLOW;
 130   if (*p == s)
 131     return LONGINT_INVALID;
 132
 133   /* Let valid_suffixes == NULL mean `allow any suffix'.  */
 134   /* FIXME: update all callers except the ones that allow suffixes
 135      after the number, changing last parameter NULL to `""'.  */
 136   if (!valid_suffixes)
 137     {
 138       *val = tmp;
 139       return LONGINT_OK;
 140     }
 141
 142   if (**p != '\0')
 143     {
 144       int base = 1024;
 145       int suffixes = 1;
 146       int overflow;
 147
 148       if (!strchr (valid_suffixes, **p))
 149         {
 150           *val = tmp;
 151           return LONGINT_INVALID_SUFFIX_CHAR;
 152         }
 153
 154       if (strchr (valid_suffixes, '0'))
 155         {
 156           /* The ``valid suffix'' '0' is a special flag meaning that
 157              an optional second suffix is allowed, which can change
 158              the base, e.g. "100MD" for 100 megabytes decimal.  */
 159
 160           switch (p[0][1])
 161             {
 162             case 'B':
 163               suffixes++;
 164               break;
 165
 166             case 'D':
 167               base = 1000;
 168               suffixes++;
 169               break;
 170             }
 171         }
 172
 173       switch (**p)
 174         {
 175         case 'b':
 176           overflow = bkm_scale (&tmp, 512);
 177           break;
 178
 179         case 'B':
 180           overflow = bkm_scale (&tmp, 1024);
 181           break;
 182
 183         case 'c':
 184           overflow = 0;
 185           break;
 186
 187         case 'E': /* Exa */
 188           overflow = bkm_scale_by_power (&tmp, base, 6);
 189           break;
 190
 191         case 'G': /* Giga */
 192           overflow = bkm_scale_by_power (&tmp, base, 3);
 193           break;
 194
 195         case 'k': /* kilo */
 196           overflow = bkm_scale_by_power (&tmp, base, 1);
 197           break;
 198
 199         case 'M': /* Mega */
 200         case 'm': /* 'm' is undocumented; for backward compatibility only */
 201           overflow = bkm_scale_by_power (&tmp, base, 2);
 202           break;
 203
 204         case 'P': /* Peta */
 205           overflow = bkm_scale_by_power (&tmp, base, 5);
 206           break;
 207
 208         case 'T': /* Tera */
 209           overflow = bkm_scale_by_power (&tmp, base, 4);
 210           break;
 211
 212         case 'w':
 213           overflow = bkm_scale (&tmp, 2);
 214           break;
 215
 216         case 'Y': /* Yotta */
 217           overflow = bkm_scale_by_power (&tmp, base, 8);
 218           break;
 219
 220         case 'Z': /* Zetta */
 221           overflow = bkm_scale_by_power (&tmp, base, 7);
 222           break;
 223
 224         default:
 225           *val = tmp;
 226           return LONGINT_INVALID_SUFFIX_CHAR;
 227           break;
 228         }
 229
 230       if (overflow)
 231         return LONGINT_OVERFLOW;
 232
 233       (*p) += suffixes;
 234     }
 235
 236   *val = tmp;
 237   return LONGINT_OK;
 238 }
 239
 240 #ifdef TESTING_XSTRTO
 241
 242 # include <stdio.h>
 243 # include "error.h"
 244
 245 char *program_name;
 246
 247 int
 248 main (int argc, char** argv)
 249 {
 250   strtol_error s_err;
 251   int i;
 252
 253   program_name = argv[0];
 254   for (i=1; i<argc; i++)
 255     {
 256       char *p;
 257       __strtol_t val;
 258
 259       s_err = __xstrtol (argv[i], &p, 0, &val, "bckmw");
 260       if (s_err == LONGINT_OK)
 261         {
 262           printf ("%s->%lu (%s)\n", argv[i], val, p);
 263         }
 264       else
 265         {
 266           STRTOL_FATAL_ERROR (argv[i], "arg", s_err);
 267         }
 268     }
 269   exit (0);
 270 }
 271
 272 #endif /* TESTING_XSTRTO */