xref: /dragonfly/contrib/diffutils/lib/xstrtol.c (revision fb151170)
1 /* A more useful interface to strtol.
2 
3    Copyright (C) 1995-1996, 1998-2001, 2003-2007, 2009-2011 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 <assert.h>
38 #include <ctype.h>
39 #include <errno.h>
40 #include <limits.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 #include "intprops.h"
45 
46 static strtol_error
47 bkm_scale (__strtol_t *x, int scale_factor)
48 {
49   if (TYPE_SIGNED (__strtol_t) && *x < STRTOL_T_MINIMUM / scale_factor)
50     {
51       *x = STRTOL_T_MINIMUM;
52       return LONGINT_OVERFLOW;
53     }
54   if (STRTOL_T_MAXIMUM / scale_factor < *x)
55     {
56       *x = STRTOL_T_MAXIMUM;
57       return LONGINT_OVERFLOW;
58     }
59   *x *= scale_factor;
60   return LONGINT_OK;
61 }
62 
63 static strtol_error
64 bkm_scale_by_power (__strtol_t *x, int base, int power)
65 {
66   strtol_error err = LONGINT_OK;
67   while (power--)
68     err |= bkm_scale (x, base);
69   return err;
70 }
71 
72 /* FIXME: comment.  */
73 
74 strtol_error
75 __xstrtol (const char *s, char **ptr, int strtol_base,
76            __strtol_t *val, const char *valid_suffixes)
77 {
78   char *t_ptr;
79   char **p;
80   __strtol_t tmp;
81   strtol_error err = LONGINT_OK;
82 
83   assert (0 <= strtol_base && strtol_base <= 36);
84 
85   p = (ptr ? ptr : &t_ptr);
86 
87   if (! TYPE_SIGNED (__strtol_t))
88     {
89       const char *q = s;
90       unsigned char ch = *q;
91       while (isspace (ch))
92         ch = *++q;
93       if (ch == '-')
94         return LONGINT_INVALID;
95     }
96 
97   errno = 0;
98   tmp = __strtol (s, p, strtol_base);
99 
100   if (*p == s)
101     {
102       /* If there is no number but there is a valid suffix, assume the
103          number is 1.  The string is invalid otherwise.  */
104       if (valid_suffixes && **p && strchr (valid_suffixes, **p))
105         tmp = 1;
106       else
107         return LONGINT_INVALID;
108     }
109   else if (errno != 0)
110     {
111       if (errno != ERANGE)
112         return LONGINT_INVALID;
113       err = LONGINT_OVERFLOW;
114     }
115 
116   /* Let valid_suffixes == NULL mean `allow any suffix'.  */
117   /* FIXME: update all callers except the ones that allow suffixes
118      after the number, changing last parameter NULL to `""'.  */
119   if (!valid_suffixes)
120     {
121       *val = tmp;
122       return err;
123     }
124 
125   if (**p != '\0')
126     {
127       int base = 1024;
128       int suffixes = 1;
129       strtol_error overflow;
130 
131       if (!strchr (valid_suffixes, **p))
132         {
133           *val = tmp;
134           return err | LONGINT_INVALID_SUFFIX_CHAR;
135         }
136 
137       if (strchr (valid_suffixes, '0'))
138         {
139           /* The ``valid suffix'' '0' is a special flag meaning that
140              an optional second suffix is allowed, which can change
141              the base.  A suffix "B" (e.g. "100MB") stands for a power
142              of 1000, whereas a suffix "iB" (e.g. "100MiB") stands for
143              a power of 1024.  If no suffix (e.g. "100M"), assume
144              power-of-1024.  */
145 
146           switch (p[0][1])
147             {
148             case 'i':
149               if (p[0][2] == 'B')
150                 suffixes += 2;
151               break;
152 
153             case 'B':
154             case 'D': /* 'D' is obsolescent */
155               base = 1000;
156               suffixes++;
157               break;
158             }
159         }
160 
161       switch (**p)
162         {
163         case 'b':
164           overflow = bkm_scale (&tmp, 512);
165           break;
166 
167         case 'B':
168           overflow = bkm_scale (&tmp, 1024);
169           break;
170 
171         case 'c':
172           overflow = 0;
173           break;
174 
175         case 'E': /* exa or exbi */
176           overflow = bkm_scale_by_power (&tmp, base, 6);
177           break;
178 
179         case 'G': /* giga or gibi */
180         case 'g': /* 'g' is undocumented; for compatibility only */
181           overflow = bkm_scale_by_power (&tmp, base, 3);
182           break;
183 
184         case 'k': /* kilo */
185         case 'K': /* kibi */
186           overflow = bkm_scale_by_power (&tmp, base, 1);
187           break;
188 
189         case 'M': /* mega or mebi */
190         case 'm': /* 'm' is undocumented; for compatibility only */
191           overflow = bkm_scale_by_power (&tmp, base, 2);
192           break;
193 
194         case 'P': /* peta or pebi */
195           overflow = bkm_scale_by_power (&tmp, base, 5);
196           break;
197 
198         case 'T': /* tera or tebi */
199         case 't': /* 't' is undocumented; for compatibility only */
200           overflow = bkm_scale_by_power (&tmp, base, 4);
201           break;
202 
203         case 'w':
204           overflow = bkm_scale (&tmp, 2);
205           break;
206 
207         case 'Y': /* yotta or 2**80 */
208           overflow = bkm_scale_by_power (&tmp, base, 8);
209           break;
210 
211         case 'Z': /* zetta or 2**70 */
212           overflow = bkm_scale_by_power (&tmp, base, 7);
213           break;
214 
215         default:
216           *val = tmp;
217           return err | LONGINT_INVALID_SUFFIX_CHAR;
218         }
219 
220       err |= overflow;
221       *p += suffixes;
222       if (**p)
223         err |= LONGINT_INVALID_SUFFIX_CHAR;
224     }
225 
226   *val = tmp;
227   return err;
228 }
229