xref: /freebsd/contrib/sendmail/libsm/strcasecmp.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*
2  * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
3  *	All rights reserved.
4  * Copyright (c) 1983, 1995-1997 Eric P. Allman.  All rights reserved.
5  * Copyright (c) 1987, 1988, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * By using this file, you agree to the terms and conditions set
9  * forth in the LICENSE file which can be found at the top level of
10  * the sendmail distribution.
11  *
12  */
13 
14 #include <sm/gen.h>
15 SM_RCSID("@(#)$Id: strcasecmp.c,v 1.15 2001/09/11 04:04:49 gshapiro Exp $")
16 
17 #include <sm/config.h>
18 #include <sm/string.h>
19 #include <string.h>
20 
21 /*
22 **  SM_STRCASECMP -- 8-bit clean version of strcasecmp
23 **
24 **	Thank you, vendors, for making this all necessary.
25 */
26 
27 /*
28 **  This array is designed for mapping upper and lower case letter
29 **  together for a case independent comparison.  The mappings are
30 **  based upon ascii character sequences.
31 */
32 
33 const unsigned char charmap[] =
34 {
35 	0000, 0001, 0002, 0003, 0004, 0005, 0006, 0007,
36 	0010, 0011, 0012, 0013, 0014, 0015, 0016, 0017,
37 	0020, 0021, 0022, 0023, 0024, 0025, 0026, 0027,
38 	0030, 0031, 0032, 0033, 0034, 0035, 0036, 0037,
39 	0040, 0041, 0042, 0043, 0044, 0045, 0046, 0047,
40 	0050, 0051, 0052, 0053, 0054, 0055, 0056, 0057,
41 	0060, 0061, 0062, 0063, 0064, 0065, 0066, 0067,
42 	0070, 0071, 0072, 0073, 0074, 0075, 0076, 0077,
43 	0100, 0141, 0142, 0143, 0144, 0145, 0146, 0147,
44 	0150, 0151, 0152, 0153, 0154, 0155, 0156, 0157,
45 	0160, 0161, 0162, 0163, 0164, 0165, 0166, 0167,
46 	0170, 0171, 0172, 0133, 0134, 0135, 0136, 0137,
47 	0140, 0141, 0142, 0143, 0144, 0145, 0146, 0147,
48 	0150, 0151, 0152, 0153, 0154, 0155, 0156, 0157,
49 	0160, 0161, 0162, 0163, 0164, 0165, 0166, 0167,
50 	0170, 0171, 0172, 0173, 0174, 0175, 0176, 0177,
51 	0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207,
52 	0210, 0211, 0212, 0213, 0214, 0215, 0216, 0217,
53 	0220, 0221, 0222, 0223, 0224, 0225, 0226, 0227,
54 	0230, 0231, 0232, 0233, 0234, 0235, 0236, 0237,
55 	0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247,
56 	0250, 0251, 0252, 0253, 0254, 0255, 0256, 0257,
57 	0260, 0261, 0262, 0263, 0264, 0265, 0266, 0267,
58 	0270, 0271, 0272, 0273, 0274, 0275, 0276, 0277,
59 	0300, 0301, 0302, 0303, 0304, 0305, 0306, 0307,
60 	0310, 0311, 0312, 0313, 0314, 0315, 0316, 0317,
61 	0320, 0321, 0322, 0323, 0324, 0325, 0326, 0327,
62 	0330, 0331, 0332, 0333, 0334, 0335, 0336, 0337,
63 	0340, 0341, 0342, 0343, 0344, 0345, 0346, 0347,
64 	0350, 0351, 0352, 0353, 0354, 0355, 0356, 0357,
65 	0360, 0361, 0362, 0363, 0364, 0365, 0366, 0367,
66 	0370, 0371, 0372, 0373, 0374, 0375, 0376, 0377,
67 };
68 
69 int
70 sm_strcasecmp(s1, s2)
71 	const char *s1, *s2;
72 {
73 	const unsigned char *us1 = (const unsigned char *)s1;
74 	const unsigned char *us2 = (const unsigned char *)s2;
75 
76 	while (charmap[*us1] == charmap[*us2])
77 	{
78 		if (*us1 == '\0')
79 			return 0;
80 		++us1;
81 		++us2;
82 	}
83 	return charmap[*us1] - charmap[*us2];
84 }
85 
86 int
87 sm_strncasecmp(s1, s2, n)
88 	const char *s1, *s2;
89 	register size_t n;
90 {
91 	if (n != 0)
92 	{
93 		register const unsigned char *cm = charmap;
94 		register const unsigned char *us1 = (const unsigned char *)s1;
95 		register const unsigned char *us2 = (const unsigned char *)s2;
96 
97 		do
98 		{
99 			if (cm[*us1] != cm[*us2++])
100 				return (cm[*us1] - cm[*--us2]);
101 			if (*us1++ == '\0')
102 				break;
103 		} while (--n != 0);
104 	}
105 	return 0;
106 }
107