Dogcows Code - chaz/tar/blob - lib/xstrtol.c

   1 /* A more useful interface to strtol.
   2    Copyright (C) 1995, 1996, 1998-2000 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 #ifndef strtol
  82 long int strtol ();
  83 #endif
  84
  85 #ifndef strtoul
  86 unsigned long int strtoul ();
  87 #endif
  88
  89 #ifndef strtoumax
  90 uintmax_t strtoumax ();
  91 #endif
  92
  93 static int
  94 bkm_scale (__strtol_t *x, int scale_factor)
  95 {
  96   __strtol_t product = *x * scale_factor;
  97   if (*x != product / scale_factor)
  98     return 1;
  99   *x = product;
 100   return 0;
 101 }
 102
 103 static int
 104 bkm_scale_by_power (__strtol_t *x, int base, int power)
 105 {
 106   while (power--)
 107     if (bkm_scale (x, base))
 108       return 1;
 109
 110   return 0;
 111 }
 112
 113 /* FIXME: comment.  */
 114
 115 strtol_error
 116 __xstrtol (const char *s, char **ptr, int strtol_base,
 117            __strtol_t *val, const char *valid_suffixes)
 118 {
 119   char *t_ptr;
 120   char **p;
 121   __strtol_t tmp;
 122
 123   assert (0 <= strtol_base && strtol_base <= 36);
 124
 125   p = (ptr ? ptr : &t_ptr);
 126
 127   if (! TYPE_SIGNED (__strtol_t))
 128     {
 129       const char *q = s;
 130       while (ISSPACE ((unsigned char) *q))
 131         ++q;
 132       if (*q == '-')
 133         return LONGINT_INVALID;
 134     }
 135
 136   errno = 0;
 137   tmp = __strtol (s, p, strtol_base);
 138   if (errno != 0)
 139     return LONGINT_OVERFLOW;
 140   if (*p == s)
 141     return LONGINT_INVALID;
 142
 143   /* Let valid_suffixes == NULL mean `allow any suffix'.  */
 144   /* FIXME: update all callers except the ones that allow suffixes
 145      after the number, changing last parameter NULL to `""'.  */
 146   if (!valid_suffixes)
 147     {
 148       *val = tmp;
 149       return LONGINT_OK;
 150     }
 151
 152   if (**p != '\0')
 153     {
 154       int base = 1024;
 155       int suffixes = 1;
 156       int overflow;
 157
 158       if (!strchr (valid_suffixes, **p))
 159         {
 160           *val = tmp;
 161           return LONGINT_INVALID_SUFFIX_CHAR;
 162         }
 163
 164       if (strchr (valid_suffixes, '0'))
 165         {
 166           /* The ``valid suffix'' '0' is a special flag meaning that
 167              an optional second suffix is allowed, which can change
 168              the base, e.g. "100MD" for 100 megabytes decimal.  */
 169
 170           switch (p[0][1])
 171             {
 172             case 'B':
 173               suffixes++;
 174               break;
 175
 176             case 'D':
 177               base = 1000;
 178               suffixes++;
 179               break;
 180             }
 181         }
 182
 183       switch (**p)
 184         {
 185         case 'b':
 186           overflow = bkm_scale (&tmp, 512);
 187           break;
 188
 189         case 'B':
 190           overflow = bkm_scale (&tmp, 1024);
 191           break;
 192
 193         case 'c':
 194           overflow = 0;
 195           break;
 196
 197         case 'E': /* Exa */
 198           overflow = bkm_scale_by_power (&tmp, base, 6);
 199           break;
 200
 201         case 'G': /* Giga */
 202         case 'g': /* 'g' is undocumented; for compatibility only */
 203           overflow = bkm_scale_by_power (&tmp, base, 3);
 204           break;
 205
 206         case 'k': /* kilo */
 207           overflow = bkm_scale_by_power (&tmp, base, 1);
 208           break;
 209
 210         case 'M': /* Mega */
 211         case 'm': /* 'm' is undocumented; for compatibility only */
 212           overflow = bkm_scale_by_power (&tmp, base, 2);
 213           break;
 214
 215         case 'P': /* Peta */
 216           overflow = bkm_scale_by_power (&tmp, base, 5);
 217           break;
 218
 219         case 'T': /* Tera */
 220         case 't': /* 't' is undocumented; for compatibility only */
 221           overflow = bkm_scale_by_power (&tmp, base, 4);
 222           break;
 223
 224         case 'w':
 225           overflow = bkm_scale (&tmp, 2);
 226           break;
 227
 228         case 'Y': /* Yotta */
 229           overflow = bkm_scale_by_power (&tmp, base, 8);
 230           break;
 231
 232         case 'Z': /* Zetta */
 233           overflow = bkm_scale_by_power (&tmp, base, 7);
 234           break;
 235
 236         default:
 237           *val = tmp;
 238           return LONGINT_INVALID_SUFFIX_CHAR;
 239           break;
 240         }
 241
 242       if (overflow)
 243         return LONGINT_OVERFLOW;
 244
 245       (*p) += suffixes;
 246     }
 247
 248   *val = tmp;
 249   return LONGINT_OK;
 250 }
 251
 252 #ifdef TESTING_XSTRTO
 253
 254 # include <stdio.h>
 255 # include "error.h"
 256
 257 char *program_name;
 258
 259 int
 260 main (int argc, char** argv)
 261 {
 262   strtol_error s_err;
 263   int i;
 264
 265   program_name = argv[0];
 266   for (i=1; i<argc; i++)
 267     {
 268       char *p;
 269       __strtol_t val;
 270
 271       s_err = __xstrtol (argv[i], &p, 0, &val, "bckmw");
 272       if (s_err == LONGINT_OK)
 273         {
 274           printf ("%s->%lu (%s)\n", argv[i], val, p);
 275         }
 276       else
 277         {
 278           STRTOL_FATAL_ERROR (argv[i], "arg", s_err);
 279         }
 280     }
 281   exit (0);
 282 }
 283
 284 #endif /* TESTING_XSTRTO */