1 /* 2 * Copyright (c) 1987 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that this notice is preserved and that due credit is given 7 * to the University of California at Berkeley. The name of the University 8 * may not be used to endorse or promote products derived from this 9 * software without specific written prior permission. This software 10 * is provided ``as is'' without express or implied warranty. 11 */ 12 13 #include "ascii_strcasecmp.h" 14 15 /* 16 * This array maps upper-case ASCII letters to their lower-case 17 * equivalents; all other byte values are mapped to themselves, 18 * so this is locale-independent and intended to be locale-independent, 19 * to avoid issues with, for example, "i" and "I" not being lower-case 20 * and upper-case versions of the same letter in Turkish, where 21 * there are separate "i with dot" and "i without dot" letters. 22 */ 23 static const 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, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 49 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 50 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 51 0xd8, 0xd9, 0xda, 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 int 59 ascii_strcasecmp(const char *s1, const char *s2) 60 { 61 register const unsigned char *cm = charmap, 62 *us1 = (const unsigned char *)s1, 63 *us2 = (const unsigned char *)s2; 64 65 while (cm[*us1] == cm[*us2++]) 66 if (*us1++ == '\0') 67 return(0); 68 return(cm[*us1] - cm[*--us2]); 69 } 70 71 int 72 ascii_strncasecmp(const char *s1, const char *s2, register size_t n) 73 { 74 register const unsigned char *cm = charmap, 75 *us1 = (const unsigned char *)s1, 76 *us2 = (const unsigned char *)s2; 77 78 for (;;) { 79 if (n == 0) { 80 /* 81 * We've run out of characters that we should 82 * compare, and they've all been equal; return 83 * 0, to indicate that the prefixes are the 84 * same. 85 */ 86 return(0); 87 } 88 if (cm[*us1] != cm[*us2++]) { 89 /* 90 * We've found a mismatch. 91 */ 92 break; 93 } 94 if (*us1++ == '\0') { 95 /* 96 * We've run out of characters *to* compare, 97 * and they've all been equal; return 0, to 98 * indicate that the strings are the same. 99 */ 100 return(0); 101 } 102 n--; 103 } 104 return(cm[*us1] - cm[*--us2]); 105 } 106
