lib/xstrtol.c

   1 /* A more useful interface to strtol.
   2
   3    Copyright (C) 1995-1996, 1998-2001, 2003-2007, 2009-2017 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 <http://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 #include "intprops.h"
  45
  46 /* xstrtoll.c and xstrtoull.c, which include this file, require that
  47    ULLONG_MAX, LLONG_MAX, LLONG_MIN are defined, but <limits.h> does not
  48    define them on all platforms.  */
  49 #ifndef ULLONG_MAX
  50 # define ULLONG_MAX TYPE_MAXIMUM (unsigned long long)
  51 #endif
  52 #ifndef LLONG_MAX
  53 # define LLONG_MAX TYPE_MAXIMUM (long long int)
  54 #endif
  55 #ifndef LLONG_MIN
  56 # define LLONG_MIN TYPE_MINIMUM (long long int)
  57 #endif
  58
  59 static strtol_error
  60 bkm_scale (__strtol_t *x, int scale_factor)
  61 {
  62   if (TYPE_SIGNED (__strtol_t) && *x < STRTOL_T_MINIMUM / scale_factor)
  63     {
  64       *x = STRTOL_T_MINIMUM;
  65       return LONGINT_OVERFLOW;
  66     }
  67   if (STRTOL_T_MAXIMUM / scale_factor < *x)
  68     {
  69       *x = STRTOL_T_MAXIMUM;
  70       return LONGINT_OVERFLOW;
  71     }
  72   *x *= scale_factor;
  73   return LONGINT_OK;
  74 }
  75
  76 static strtol_error
  77 bkm_scale_by_power (__strtol_t *x, int base, int power)
  78 {
  79   strtol_error err = LONGINT_OK;
  80   while (power--)
  81     err |= bkm_scale (x, base);
  82   return err;
  83 }
  84
  85 /* FIXME: comment.  */
  86
  87 strtol_error
  88 __xstrtol (const char *s, char **ptr, int strtol_base,
  89            __strtol_t *val, const char *valid_suffixes)
  90 {
  91   char *t_ptr;
  92   char **p;
  93   __strtol_t tmp;
  94   strtol_error err = LONGINT_OK;
  95
  96   assure (0 <= strtol_base && strtol_base <= 36);
  97
  98   p = (ptr ? ptr : &t_ptr);
  99
 100   errno = 0;
 101
 102   if (! TYPE_SIGNED (__strtol_t))
 103     {
 104       const char *q = s;
 105       unsigned char ch = *q;
 106       while (isspace (ch))
 107         ch = *++q;
 108       if (ch == '-')
 109         return LONGINT_INVALID;
 110     }
 111
 112   tmp = __strtol (s, p, strtol_base);
 113
 114   if (*p == s)
 115     {
 116       /* If there is no number but there is a valid suffix, assume the
 117          number is 1.  The string is invalid otherwise.  */
 118       if (valid_suffixes && **p && strchr (valid_suffixes, **p))
 119         tmp = 1;
 120       else
 121         return LONGINT_INVALID;
 122     }
 123   else if (errno != 0)
 124     {
 125       if (errno != ERANGE)
 126         return LONGINT_INVALID;
 127       err = LONGINT_OVERFLOW;
 128     }
 129
 130   /* Let valid_suffixes == NULL mean "allow any suffix".  */
 131   /* FIXME: update all callers except the ones that allow suffixes
 132      after the number, changing last parameter NULL to "".  */
 133   if (!valid_suffixes)
 134     {
 135       *val = tmp;
 136       return err;
 137     }
 138
 139   if (**p != '\0')
 140     {
 141       int base = 1024;
 142       int suffixes = 1;
 143       strtol_error overflow;
 144
 145       if (!strchr (valid_suffixes, **p))
 146         {
 147           *val = tmp;
 148           return err | LONGINT_INVALID_SUFFIX_CHAR;
 149         }
 150
 151       switch (**p)
 152         {
 153         case 'E': case 'G': case 'g': case 'k': case 'K': case 'M': case 'm':
 154         case 'P': case 'T': case 't': case 'Y': case 'Z':
 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.  A suffix "B" (e.g. "100MB") stands for a power
 159              of 1000, whereas a suffix "iB" (e.g. "100MiB") stands for
 160              a power of 1024.  If no suffix (e.g. "100M"), assume
 161              power-of-1024.  */
 162
 163           if (strchr (valid_suffixes, '0'))
 164             switch (p[0][1])
 165               {
 166               case 'i':
 167                 if (p[0][2] == 'B')
 168                   suffixes += 2;
 169                 break;
 170
 171               case 'B':
 172               case 'D': /* 'D' is obsolescent */
 173                 base = 1000;
 174                 suffixes++;
 175                 break;
 176               }
 177         }
 178
 179       switch (**p)
 180         {
 181         case 'b':
 182           overflow = bkm_scale (&tmp, 512);
 183           break;
 184
 185         case 'B':
 186           /* This obsolescent first suffix is distinct from the 'B'
 187              second suffix above.  E.g., 'tar -L 1000B' means change
 188              the tape after writing 1000 KiB of data.  */
 189           overflow = bkm_scale (&tmp, 1024);
 190           break;
 191
 192         case 'c':
 193           overflow = LONGINT_OK;
 194           break;
 195
 196         case 'E': /* exa or exbi */
 197           overflow = bkm_scale_by_power (&tmp, base, 6);
 198           break;
 199
 200         case 'G': /* giga or gibi */
 201         case 'g': /* 'g' is undocumented; for compatibility only */
 202           overflow = bkm_scale_by_power (&tmp, base, 3);
 203           break;
 204
 205         case 'k': /* kilo */
 206         case 'K': /* kibi */
 207           overflow = bkm_scale_by_power (&tmp, base, 1);
 208           break;
 209
 210         case 'M': /* mega or mebi */
 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 or pebi */
 216           overflow = bkm_scale_by_power (&tmp, base, 5);
 217           break;
 218
 219         case 'T': /* tera or tebi */
 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 or 2**80 */
 229           overflow = bkm_scale_by_power (&tmp, base, 8);
 230           break;
 231
 232         case 'Z': /* zetta or 2**70 */
 233           overflow = bkm_scale_by_power (&tmp, base, 7);
 234           break;
 235
 236         default:
 237           *val = tmp;
 238           return err | LONGINT_INVALID_SUFFIX_CHAR;
 239         }
 240
 241       err |= overflow;
 242       *p += suffixes;
 243       if (**p)
 244         err |= LONGINT_INVALID_SUFFIX_CHAR;
 245     }
 246
 247   *val = tmp;
 248   return err;
 249 }