lib/xstrtol.c

   1 /* A more useful interface to strtol.
   2
   3    Copyright (C) 1995-1996, 1998-2001, 2003-2007, 2009-2020 Free Software
   4    Foundation, Inc.
   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 3 of the License, or
   9    (at your option) 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, see <https://www.gnu.org/licenses/>.  */
  18
  19 /* Written by Jim Meyering. */
  20
  21 #ifndef __strtol
  22 # define __strtol strtol
  23 # define __strtol_t long int
  24 # define __xstrtol xstrtol
  25 # define STRTOL_T_MINIMUM LONG_MIN
  26 # define STRTOL_T_MAXIMUM LONG_MAX
  27 #endif
  28
  29 #include <config.h>
  30
  31 #include "xstrtol.h"
  32
  33 /* Some pre-ANSI implementations (e.g. SunOS 4)
  34    need stderr defined if assertion checking is enabled.  */
  35 #include <stdio.h>
  36
  37 #include <ctype.h>
  38 #include <errno.h>
  39 #include <limits.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42
  43 #include "assure.h"
  44
  45 #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
  46
  47 static strtol_error
  48 bkm_scale (__strtol_t *x, int scale_factor)
  49 {
  50   if (TYPE_SIGNED (__strtol_t) && *x < STRTOL_T_MINIMUM / scale_factor)
  51     {
  52       *x = STRTOL_T_MINIMUM;
  53       return LONGINT_OVERFLOW;
  54     }
  55   if (STRTOL_T_MAXIMUM / scale_factor < *x)
  56     {
  57       *x = STRTOL_T_MAXIMUM;
  58       return LONGINT_OVERFLOW;
  59     }
  60   *x *= scale_factor;
  61   return LONGINT_OK;
  62 }
  63
  64 static strtol_error
  65 bkm_scale_by_power (__strtol_t *x, int base, int power)
  66 {
  67   strtol_error err = LONGINT_OK;
  68   while (power--)
  69     err |= bkm_scale (x, base);
  70   return err;
  71 }
  72
  73 /* FIXME: comment.  */
  74
  75 strtol_error
  76 __xstrtol (const char *s, char **ptr, int strtol_base,
  77            __strtol_t *val, const char *valid_suffixes)
  78 {
  79   char *t_ptr;
  80   char **p;
  81   __strtol_t tmp;
  82   strtol_error err = LONGINT_OK;
  83
  84   assure (0 <= strtol_base && strtol_base <= 36);
  85
  86   p = (ptr ? ptr : &t_ptr);
  87
  88   errno = 0;
  89
  90   if (! TYPE_SIGNED (__strtol_t))
  91     {
  92       const char *q = s;
  93       unsigned char ch = *q;
  94       while (isspace (ch))
  95         ch = *++q;
  96       if (ch == '-')
  97         return LONGINT_INVALID;
  98     }
  99
 100   tmp = __strtol (s, p, strtol_base);
 101
 102   if (*p == s)
 103     {
 104       /* If there is no number but there is a valid suffix, assume the
 105          number is 1.  The string is invalid otherwise.  */
 106       if (valid_suffixes && **p && strchr (valid_suffixes, **p))
 107         tmp = 1;
 108       else
 109         return LONGINT_INVALID;
 110     }
 111   else if (errno != 0)
 112     {
 113       if (errno != ERANGE)
 114         return LONGINT_INVALID;
 115       err = LONGINT_OVERFLOW;
 116     }
 117
 118   /* Let valid_suffixes == NULL mean "allow any suffix".  */
 119   /* FIXME: update all callers except the ones that allow suffixes
 120      after the number, changing last parameter NULL to "".  */
 121   if (!valid_suffixes)
 122     {
 123       *val = tmp;
 124       return err;
 125     }
 126
 127   if (**p != '\0')
 128     {
 129       int base = 1024;
 130       int suffixes = 1;
 131       strtol_error overflow;
 132
 133       if (!strchr (valid_suffixes, **p))
 134         {
 135           *val = tmp;
 136           return err | LONGINT_INVALID_SUFFIX_CHAR;
 137         }
 138
 139       switch (**p)
 140         {
 141         case 'E': case 'G': case 'g': case 'k': case 'K': case 'M': case 'm':
 142         case 'P': case 'T': case 't': case 'Y': case 'Z':
 143
 144           /* The "valid suffix" '0' is a special flag meaning that
 145              an optional second suffix is allowed, which can change
 146              the base.  A suffix "B" (e.g. "100MB") stands for a power
 147              of 1000, whereas a suffix "iB" (e.g. "100MiB") stands for
 148              a power of 1024.  If no suffix (e.g. "100M"), assume
 149              power-of-1024.  */
 150
 151           if (strchr (valid_suffixes, '0'))
 152             switch (p[0][1])
 153               {
 154               case 'i':
 155                 if (p[0][2] == 'B')
 156                   suffixes += 2;
 157                 break;
 158
 159               case 'B':
 160               case 'D': /* 'D' is obsolescent */
 161                 base = 1000;
 162                 suffixes++;
 163                 break;
 164               }
 165         }
 166
 167       switch (**p)
 168         {
 169         case 'b':
 170           overflow = bkm_scale (&tmp, 512);
 171           break;
 172
 173         case 'B':
 174           /* This obsolescent first suffix is distinct from the 'B'
 175              second suffix above.  E.g., 'tar -L 1000B' means change
 176              the tape after writing 1000 KiB of data.  */
 177           overflow = bkm_scale (&tmp, 1024);
 178           break;
 179
 180         case 'c':
 181           overflow = LONGINT_OK;
 182           break;
 183
 184         case 'E': /* exa or exbi */
 185           overflow = bkm_scale_by_power (&tmp, base, 6);
 186           break;
 187
 188         case 'G': /* giga or gibi */
 189         case 'g': /* 'g' is undocumented; for compatibility only */
 190           overflow = bkm_scale_by_power (&tmp, base, 3);
 191           break;
 192
 193         case 'k': /* kilo */
 194         case 'K': /* kibi */
 195           overflow = bkm_scale_by_power (&tmp, base, 1);
 196           break;
 197
 198         case 'M': /* mega or mebi */
 199         case 'm': /* 'm' is undocumented; for compatibility only */
 200           overflow = bkm_scale_by_power (&tmp, base, 2);
 201           break;
 202
 203         case 'P': /* peta or pebi */
 204           overflow = bkm_scale_by_power (&tmp, base, 5);
 205           break;
 206
 207         case 'T': /* tera or tebi */
 208         case 't': /* 't' is undocumented; for compatibility only */
 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 or 2**80 */
 217           overflow = bkm_scale_by_power (&tmp, base, 8);
 218           break;
 219
 220         case 'Z': /* zetta or 2**70 */
 221           overflow = bkm_scale_by_power (&tmp, base, 7);
 222           break;
 223
 224         default:
 225           *val = tmp;
 226           return err | LONGINT_INVALID_SUFFIX_CHAR;
 227         }
 228
 229       err |= overflow;
 230       *p += suffixes;
 231       if (**p)
 232         err |= LONGINT_INVALID_SUFFIX_CHAR;
 233     }
 234
 235   *val = tmp;
 236   return err;
 237 }