File: /usr/src/linux/fs/hfs/string.c
1 /*
2 * linux/fs/hfs/string.c
3 *
4 * Copyright (C) 1995-1997 Paul H. Hargrove
5 * This file may be distributed under the terms of the GNU General Public License.
6 *
7 * This file contains the string comparison function for the
8 * Macintosh character set.
9 *
10 * The code in this file is derived from code which is copyright
11 * 1986, 1989, 1990 by Abacus Research and Development, Inc. (ARDI)
12 * It is used here by the permission of ARDI's president Cliff Matthews.
13 *
14 * If you discover bugs in this code please notify both the author of the
15 * Linux HFS file system: hargrove@sccm.stanford.edu (Paul H. Hargrove)
16 * and the author of ARDI's HFS code: ctm@ardi.com (Clifford T. Matthews)
17 *
18 * "XXX" in a comment is a note to myself to consider changing something.
19 */
20
21 #include "hfs.h"
22
23 /*================ File-local variables ================*/
24
25 /*
26 * unsigned char caseorder[]
27 *
28 * Defines the lexical ordering of characters on the Macintosh
29 *
30 * Composition of the 'casefold' and 'order' tables from ARDI's code
31 * with the entry for 0x20 changed to match that for 0xCA to remove
32 * special case for those two characters.
33 */
34 static unsigned char caseorder[256] = {
35 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
36 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
37 0x20,0x22,0x23,0x28,0x29,0x2A,0x2B,0x2C,0x2F,0x30,0x31,0x32,0x33,0x34,0x35,0x36,
38 0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,0x40,0x41,0x42,0x43,0x44,0x45,0x46,
39 0x47,0x48,0x57,0x59,0x5D,0x5F,0x66,0x68,0x6A,0x6C,0x72,0x74,0x76,0x78,0x7A,0x7E,
40 0x8C,0x8E,0x90,0x92,0x95,0x97,0x9E,0xA0,0xA2,0xA4,0xA7,0xA9,0xAA,0xAB,0xAC,0xAD,
41 0x4E,0x48,0x57,0x59,0x5D,0x5F,0x66,0x68,0x6A,0x6C,0x72,0x74,0x76,0x78,0x7A,0x7E,
42 0x8C,0x8E,0x90,0x92,0x95,0x97,0x9E,0xA0,0xA2,0xA4,0xA7,0xAF,0xB0,0xB1,0xB2,0xB3,
43 0x4A,0x4C,0x5A,0x60,0x7B,0x7F,0x98,0x4F,0x49,0x51,0x4A,0x4B,0x4C,0x5A,0x60,0x63,
44 0x64,0x65,0x6E,0x6F,0x70,0x71,0x7B,0x84,0x85,0x86,0x7F,0x80,0x9A,0x9B,0x9C,0x98,
45 0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0x94,0xBB,0xBC,0xBD,0xBE,0xBF,0xC0,0x4D,0x81,
46 0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xCB,0x55,0x8A,0xCC,0x4D,0x81,
47 0xCD,0xCE,0xCF,0xD0,0xD1,0xD2,0xD3,0x26,0x27,0xD4,0x20,0x49,0x4B,0x80,0x82,0x82,
48 0xD5,0xD6,0x24,0x25,0x2D,0x2E,0xD7,0xD8,0xA6,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
49 0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
50 0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF
51 };
52
53 /*
54 * unsigned char casefold[]
55 *
56 * Defines the mapping to lowercase characters on the Macintosh
57 *
58 * "Inverse" of the 'casefold' from ARDI's code.
59 */
60 static unsigned char casefold[256] = {
61 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
62 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
63 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,
64 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,
65 0x40,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,
66 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x5B,0x5C,0x5D,0x5E,0x5F,
67 0x41,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,
68 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F,
69 0x8A,0x8C,0x8D,0x8E,0x96,0x9A,0x9F,0x87,0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F,
70 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F,
71 0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xBE,0xBF,
72 0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF,
73 0xC0,0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0x88,0x8B,0x9B,0xCF,0xCF,
74 0xD0,0xD1,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
75 0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
76 0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF
77 };
78
79 /*================ Global functions ================*/
80
81 /*
82 * Hash a string to an integer in a case-independent way
83 */
84 unsigned int hfs_strhash(const unsigned char *name, unsigned int len)
85 {
86 unsigned long hash = init_name_hash();
87
88 while (len--)
89 hash = partial_name_hash(caseorder[*name++],
90 hash);
91 return end_name_hash(hash);
92 }
93
94 /*
95 * Compare two strings in the HFS filename character ordering
96 * Returns positive, negative, or zero, not just 0 or (+/-)1
97 *
98 * Equivalent to ARDI's call:
99 * ROMlib_RelString(s1+1, s2+1, true, false, (s1[0]<<16) | s2[0])
100 */
101 int hfs_strcmp(const unsigned char *s1, unsigned int len1,
102 const unsigned char *s2, unsigned int len2)
103 {
104 int len, tmp;
105
106 len = (len1 > len2) ? len2 : len1;
107
108 while (len--) {
109 if ((tmp = (int)caseorder[*(s1++)] -
110 (int)caseorder[*(s2++)])) {
111 return tmp;
112 }
113 }
114 return len1 - len2;
115 }
116
117 /*
118 * Test for equality of two strings in the HFS filename character ordering.
119 */
120 int hfs_streq(const unsigned char *s1, unsigned int len1,
121 const unsigned char *s2, unsigned int len2)
122 {
123 if (len1 != len2) {
124 return 0;
125 }
126
127 while (len1--) {
128 if (caseorder[*(s1++)] != caseorder[*(s2++)]) {
129 return 0;
130 }
131 }
132 return 1;
133 }
134
135 /*
136 * Convert a string to the Macintosh version of lower case.
137 */
138 void hfs_tolower(unsigned char *p, int len)
139 {
140 while (len--) {
141 *p = casefold[*p];
142 ++p;
143 }
144 }
145