1/*
2 * strncasecmp.c --
3 *
4 *	Source code for the "strncasecmp" library routine.
5 *
6 * Copyright (c) 1988-1993 The Regents of the University of California.
7 * Copyright (c) 1995-1996 Sun Microsystems, Inc.
8 *
9 * See the file "license.terms" for information on usage and redistribution
10 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
11 *
12 * RCS: @(#) $Id: strncasecmp.c,v 1.2 1998/09/14 18:39:45 stanton Exp $
13 */
14
15#include "tclPort.h"
16
17/*
18 * This array is designed for mapping upper and lower case letter
19 * together for a case independent comparison.  The mappings are
20 * based upon ASCII character sequences.
21 */
22
23static unsigned char charmap[] = {
24    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
25    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
26    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
27    0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
28    0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
29    0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
30    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
31    0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
32    0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
33    0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
34    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
35    0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
36    0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
37    0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
38    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
39    0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
40    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
41    0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
42    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
43    0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
44    0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
45    0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
46    0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
47    0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
48    0xc0, 0xe1, 0xe2, 0xe3, 0xe4, 0xc5, 0xe6, 0xe7,
49    0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
50    0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
51    0xf8, 0xf9, 0xfa, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
52    0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
53    0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
54    0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
55    0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
56};
57
58/*
59 * Here are the prototypes just in case they are not included
60 * in tclPort.h.
61 */
62int		strncasecmp _ANSI_ARGS_((CONST char *s1,
63			    CONST char *s2, size_t n));
64
65int		strcasecmp _ANSI_ARGS_((CONST char *s1,
66			    CONST char *s2));
67
68/*
69 *----------------------------------------------------------------------
70 *
71 * strcasecmp --
72 *
73 *	Compares two strings, ignoring case differences.
74 *
75 * Results:
76 *	Compares two null-terminated strings s1 and s2, returning -1, 0,
77 *	or 1 if s1 is lexicographically less than, equal to, or greater
78 *	than s2.
79 *
80 * Side effects:
81 *	None.
82 *
83 *----------------------------------------------------------------------
84 */
85
86int
87strcasecmp(s1, s2)
88    CONST char *s1;			/* First string. */
89    CONST char *s2;			/* Second string. */
90{
91    unsigned char u1, u2;
92
93    for ( ; ; s1++, s2++) {
94	u1 = (unsigned char) *s1;
95	u2 = (unsigned char) *s2;
96	if ((u1 == '\0') || (charmap[u1] != charmap[u2])) {
97	    break;
98	}
99    }
100    return charmap[u1] - charmap[u2];
101}
102
103/*
104 *----------------------------------------------------------------------
105 *
106 * strncasecmp --
107 *
108 *	Compares two strings, ignoring case differences.
109 *
110 * Results:
111 *	Compares up to length chars of s1 and s2, returning -1, 0, or 1
112 *	if s1 is lexicographically less than, equal to, or greater
113 *	than s2 over those characters.
114 *
115 * Side effects:
116 *	None.
117 *
118 *----------------------------------------------------------------------
119 */
120
121int
122strncasecmp(s1, s2, length)
123    CONST char *s1;		/* First string. */
124    CONST char *s2;		/* Second string. */
125    size_t length;		/* Maximum number of characters to compare
126				 * (stop earlier if the end of either string
127				 * is reached). */
128{
129    unsigned char u1, u2;
130
131    for (; length != 0; length--, s1++, s2++) {
132	u1 = (unsigned char) *s1;
133	u2 = (unsigned char) *s2;
134	if (charmap[u1] != charmap[u2]) {
135	    return charmap[u1] - charmap[u2];
136	}
137	if (u1 == '\0') {
138	    return 0;
139	}
140    }
141    return 0;
142}
143