usr/src/cmd/sendmail/libsm/strcasecmp.c

   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 #pragma ident   "%Z%%M% %I%     %E% SMI"
  15
  16 #include <sm/gen.h>
  17 SM_RCSID("@(#)$Id: strcasecmp.c,v 1.12 2001/08/27 22:09:15 gshapiro Exp $")
  18
  19 #include <sm/config.h>
  20 #include <sm/string.h>
  21 #include <string.h>
  22
  23 \f/*
  24 **  SM_STRCASECMP -- 8-bit clean version of strcasecmp
  25 **
  26 **      Thank you, vendors, for making this all necessary.
  27 */
  28
  29 /*
  30 **  This array is designed for mapping upper and lower case letter
  31 **  together for a case independent comparison.  The mappings are
  32 **  based upon ascii character sequences.
  33 */
  34
  35 const unsigned char charmap[] =
  36 {
  37         0000, 0001, 0002, 0003, 0004, 0005, 0006, 0007,
  38         0010, 0011, 0012, 0013, 0014, 0015, 0016, 0017,
  39         0020, 0021, 0022, 0023, 0024, 0025, 0026, 0027,
  40         0030, 0031, 0032, 0033, 0034, 0035, 0036, 0037,
  41         0040, 0041, 0042, 0043, 0044, 0045, 0046, 0047,
  42         0050, 0051, 0052, 0053, 0054, 0055, 0056, 0057,
  43         0060, 0061, 0062, 0063, 0064, 0065, 0066, 0067,
  44         0070, 0071, 0072, 0073, 0074, 0075, 0076, 0077,
  45         0100, 0141, 0142, 0143, 0144, 0145, 0146, 0147,
  46         0150, 0151, 0152, 0153, 0154, 0155, 0156, 0157,
  47         0160, 0161, 0162, 0163, 0164, 0165, 0166, 0167,
  48         0170, 0171, 0172, 0133, 0134, 0135, 0136, 0137,
  49         0140, 0141, 0142, 0143, 0144, 0145, 0146, 0147,
  50         0150, 0151, 0152, 0153, 0154, 0155, 0156, 0157,
  51         0160, 0161, 0162, 0163, 0164, 0165, 0166, 0167,
  52         0170, 0171, 0172, 0173, 0174, 0175, 0176, 0177,
  53         0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207,
  54         0210, 0211, 0212, 0213, 0214, 0215, 0216, 0217,
  55         0220, 0221, 0222, 0223, 0224, 0225, 0226, 0227,
  56         0230, 0231, 0232, 0233, 0234, 0235, 0236, 0237,
  57         0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247,
  58         0250, 0251, 0252, 0253, 0254, 0255, 0256, 0257,
  59         0260, 0261, 0262, 0263, 0264, 0265, 0266, 0267,
  60         0270, 0271, 0272, 0273, 0274, 0275, 0276, 0277,
  61         0300, 0301, 0302, 0303, 0304, 0305, 0306, 0307,
  62         0310, 0311, 0312, 0313, 0314, 0315, 0316, 0317,
  63         0320, 0321, 0322, 0323, 0324, 0325, 0326, 0327,
  64         0330, 0331, 0332, 0333, 0334, 0335, 0336, 0337,
  65         0340, 0341, 0342, 0343, 0344, 0345, 0346, 0347,
  66         0350, 0351, 0352, 0353, 0354, 0355, 0356, 0357,
  67         0360, 0361, 0362, 0363, 0364, 0365, 0366, 0367,
  68         0370, 0371, 0372, 0373, 0374, 0375, 0376, 0377,
  69 };
  70
  71 int
  72 sm_strcasecmp(s1, s2)
  73         const char *s1, *s2;
  74 {
  75         const unsigned char *us1 = (const unsigned char *)s1;
  76         const unsigned char *us2 = (const unsigned char *)s2;
  77
  78         while (charmap[*us1] == charmap[*us2])
  79         {
  80                 if (*us1 == '\0')
  81                         return 0;
  82                 ++us1;
  83                 ++us2;
  84         }
  85         return charmap[*us1] - charmap[*us2];
  86 }
  87
  88 int
  89 sm_strncasecmp(s1, s2, n)
  90         const char *s1, *s2;
  91         register size_t n;
  92 {
  93         if (n != 0)
  94         {
  95                 register const unsigned char *cm = charmap;
  96                 register const unsigned char *us1 = (const unsigned char *)s1;
  97                 register const unsigned char *us2 = (const unsigned char *)s2;
  98
  99                 do
 100                 {
 101                         if (cm[*us1] != cm[*us2++])
 102                                 return (cm[*us1] - cm[*--us2]);
 103                         if (*us1++ == '\0')
 104                                 break;
 105                 } while (--n != 0);
 106         }
 107         return 0;
 108 }