1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28 #include <stddef.h>
29 #include <stdint.h>
30 #include <ctype.h>
31
digitval(int ch)32 static inline int digitval(int ch)
33 {
34 unsigned d;
35
36 d = (unsigned)(ch - '0');
37 if (d < 10) return (int)d;
38
39 d = (unsigned)(ch - 'a');
40 if (d < 6) return (int)(d+10);
41
42 d = (unsigned)(ch - 'A');
43 if (d < 6) return (int)(d+10);
44
45 return -1;
46 }
47
48 uintmax_t
strntoumax(const char * nptr,char ** endptr,int base,size_t n)49 strntoumax(const char *nptr, char **endptr, int base, size_t n)
50 {
51 const unsigned char* p = (const unsigned char *)nptr;
52 const unsigned char* end = p + n;
53 int minus = 0;
54 uintmax_t v = 0;
55 int d;
56
57 /* skip leading space */
58 while (p < end && isspace(*p))
59 p++;
60
61 /* Single optional + or - */
62 if (p < end) {
63 char c = p[0];
64 if ( c == '-' || c == '+' ) {
65 minus = (c == '-');
66 p++;
67 }
68 }
69
70 if ( base == 0 ) {
71 if ( p+2 < end && p[0] == '0' && (p[1] == 'x' || p[1] == 'X') ) {
72 p += 2;
73 base = 16;
74 } else if ( p+1 < end && p[0] == '0' ) {
75 p += 1;
76 base = 8;
77 } else {
78 base = 10;
79 }
80 } else if ( base == 16 ) {
81 if ( p+2 < end && p[0] == '0' && (p[1] == 'x' || p[1] == 'X') ) {
82 p += 2;
83 }
84 }
85
86 while ( p < end && (d = digitval(*p)) >= 0 && d < base ) {
87 v = v*base + d;
88 p += 1;
89 }
90
91 if ( endptr )
92 *endptr = (char *)p;
93
94 return minus ? -v : v;
95 }
96