1 /*
2 * Copyright (C) 1998,1999 Uwe Ohse
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 of the License, or
7 * (at your option) 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
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 *
18 * As a special exception this source may be used as part of the
19 * SRS project by CORE/Computer Service Langenbach
20 * regardless of the copyright they choose.
21 *
22 * Contact: uwe@ohse.de
23 */
24 /* written mainly to get around the need to include a strtoul.c in the distributions */
25 #include "config.h"
26 #include "str2num.h"
27
28 int
str2ulong(const char * s,unsigned long * ul,int base)29 str2ulong (const char *s, unsigned long *ul, int base)
30 {
31 unsigned long x = 0;
32 const char *t = s;
33 if (base == 0 && *s == '0') {
34 if (s[1] == 'x' || s[1] == 'X') {
35 base = 16;
36 s += 2;
37 } else {
38 base = 8;
39 s++;
40 if (!*s) {
41 *ul = 0;
42 return 1;
43 }
44 }
45 } else if (base == 0)
46 base = 10;
47 else if (base == 16 && *s == '0') { /* as strtoul compatible as possible */
48 if ((s[1] == 'x' || s[1] == 'X') && s[2])
49 s += 2;
50 }
51 /* i assume something about processor behaviour in case of overflow ... */
52 /* and, of course, about the character set */
53 while (*s) {
54 unsigned int c = (unsigned char) *s;
55 int v;
56 unsigned long old;
57 if (c < '0' || c > '9') {
58 if (c >= 'a' && c <= 'z')
59 v = (c - 'a');
60 else if (c >= 'A' && c <= 'Z')
61 v = (c - 'A');
62 else
63 goto out;
64 v += 10;
65 } else
66 v = c - '0';
67 if (v >= base)
68 goto out;
69 old = x;
70 x *= (unsigned long) base;
71 x += (unsigned long) v;
72 if (x < old)
73 return -1;
74 s++;
75 }
76 out:
77 *ul = x;
78 return s - t;
79 }
80