lib/xstrtol.c

   1 /* A more useful interface to strtol.
   2
   3    Copyright (C) 1995-1996, 1998-2001, 2003-2007, 2009-2024 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 <stdckdint.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43
  44 #if XSTRTOL_INCLUDE_INTTYPES_H
  45 # include <inttypes.h>
  46 #endif
  47
  48 #include "assure.h"
  49 #include "intprops.h"
  50
  51 static strtol_error
  52 bkm_scale (__strtol_t *x, int scale_factor)
  53 {
  54   __strtol_t scaled;
  55   if (ckd_mul (&scaled, *x, scale_factor))
  56     {
  57       *x = *x < 0 ? TYPE_MINIMUM (__strtol_t) : TYPE_MAXIMUM (__strtol_t);
  58       return LONGINT_OVERFLOW;
  59     }
  60
  61   *x = scaled;
  62
  63   return LONGINT_OK;
  64 }
  65
  66 static strtol_error
  67 bkm_scale_by_power (__strtol_t *x, int base, int power)
  68 {
  69   strtol_error err = LONGINT_OK;
  70   while (power--)
  71     err |= bkm_scale (x, base);
  72   return err;
  73 }
  74
  75 /* FIXME: comment.  */
  76
  77 strtol_error
  78 __xstrtol (const char *s, char **ptr, int strtol_base,
  79            __strtol_t *val, const char *valid_suffixes)
  80 {
  81   char *t_ptr;
  82   char **p;
  83   __strtol_t tmp;
  84   strtol_error err = LONGINT_OK;
  85
  86   assure (0 <= strtol_base && strtol_base <= 36);
  87
  88   p = (ptr ? ptr : &t_ptr);
  89
  90   errno = 0;
  91
  92   if (! TYPE_SIGNED (__strtol_t))
  93     {
  94       const char *q = s;
  95       unsigned char ch = *q;
  96       while (isspace (ch))
  97         ch = *++q;
  98       if (ch == '-')
  99         return LONGINT_INVALID;
 100     }
 101
 102   tmp = __strtol (s, p, strtol_base);
 103
 104   if (*p == s)
 105     {
 106       /* If there is no number but there is a valid suffix, assume the
 107          number is 1.  The string is invalid otherwise.  */
 108       if (valid_suffixes && **p && strchr (valid_suffixes, **p))
 109         tmp = 1;
 110       else
 111         return LONGINT_INVALID;
 112     }
 113   else if (errno != 0)
 114     {
 115       if (errno != ERANGE)
 116         return LONGINT_INVALID;
 117       err = LONGINT_OVERFLOW;
 118     }
 119
 120   /* Let valid_suffixes == NULL mean "allow any suffix".  */
 121   /* FIXME: update all callers except the ones that allow suffixes
 122      after the number, changing last parameter NULL to "".  */
 123   if (!valid_suffixes)
 124     {
 125       *val = tmp;
 126       return err;
 127     }
 128
 129   if (**p != '\0')
 130     {
 131       int base = 1024;
 132       int suffixes = 1;
 133       strtol_error overflow;
 134
 135       if (!strchr (valid_suffixes, **p))
 136         {
 137           *val = tmp;
 138           return err | LONGINT_INVALID_SUFFIX_CHAR;
 139         }
 140
 141       switch (**p)
 142         {
 143         case 'E': case 'G': case 'g': case 'k': case 'K': case 'M': case 'm':
 144         case 'P': case 'Q': case 'R': case 'T': case 't': case 'Y': case 'Z':
 145
 146           /* The "valid suffix" '0' is a special flag meaning that
 147              an optional second suffix is allowed, which can change
 148              the base.  A suffix "B" (e.g. "100MB") stands for a power
 149              of 1000, whereas a suffix "iB" (e.g. "100MiB") stands for
 150              a power of 1024.  If no suffix (e.g. "100M"), assume
 151              power-of-1024.  */
 152
 153           if (strchr (valid_suffixes, '0'))
 154             switch (p[0][1])
 155               {
 156               case 'i':
 157                 if (p[0][2] == 'B')
 158                   suffixes += 2;
 159                 break;
 160
 161               case 'B':
 162               case 'D': /* 'D' is obsolescent */
 163                 base = 1000;
 164                 suffixes++;
 165                 break;
 166               }
 167         }
 168
 169       switch (**p)
 170         {
 171         case 'b':
 172           overflow = bkm_scale (&tmp, 512);
 173           break;
 174
 175         case 'B':
 176           /* This obsolescent first suffix is distinct from the 'B'
 177              second suffix above.  E.g., 'tar -L 1000B' means change
 178              the tape after writing 1000 KiB of data.  */
 179           overflow = bkm_scale (&tmp, 1024);
 180           break;
 181
 182         case 'c':
 183           overflow = LONGINT_OK;
 184           break;
 185
 186         case 'E': /* exa or exbi */
 187           overflow = bkm_scale_by_power (&tmp, base, 6);
 188           break;
 189
 190         case 'G': /* giga or gibi */
 191         case 'g': /* 'g' is undocumented; for compatibility only */
 192           overflow = bkm_scale_by_power (&tmp, base, 3);
 193           break;
 194
 195         case 'k': /* kilo */
 196         case 'K': /* kibi */
 197           overflow = bkm_scale_by_power (&tmp, base, 1);
 198           break;
 199
 200         case 'M': /* mega or mebi */
 201         case 'm': /* 'm' is undocumented; for compatibility only */
 202           overflow = bkm_scale_by_power (&tmp, base, 2);
 203           break;
 204
 205         case 'P': /* peta or pebi */
 206           overflow = bkm_scale_by_power (&tmp, base, 5);
 207           break;
 208
 209         case 'Q': /* quetta or 2**100 */
 210           overflow = bkm_scale_by_power (&tmp, base, 10);
 211           break;
 212
 213         case 'R': /* ronna or 2**90 */
 214           overflow = bkm_scale_by_power (&tmp, base, 9);
 215           break;
 216
 217         case 'T': /* tera or tebi */
 218         case 't': /* 't' is undocumented; for compatibility only */
 219           overflow = bkm_scale_by_power (&tmp, base, 4);
 220           break;
 221
 222         case 'w':
 223           overflow = bkm_scale (&tmp, 2);
 224           break;
 225
 226         case 'Y': /* yotta or 2**80 */
 227           overflow = bkm_scale_by_power (&tmp, base, 8);
 228           break;
 229
 230         case 'Z': /* zetta or 2**70 */
 231           overflow = bkm_scale_by_power (&tmp, base, 7);
 232           break;
 233
 234         default:
 235           *val = tmp;
 236           return err | LONGINT_INVALID_SUFFIX_CHAR;
 237         }
 238
 239       err |= overflow;
 240       *p += suffixes;
 241       if (**p)
 242         err |= LONGINT_INVALID_SUFFIX_CHAR;
 243     }
 244
 245   *val = tmp;
 246   return err;
 247 }