strcasecmp.c   [plain text]

/*
 * Copyright (c) 2004-2005 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <config.h>
#include <compat.h>

/*
 * Case insensitive string compare routines, same semantics as str[n]cmp()
 * (assumes ASCII..).
 * Derived from a public domain implementation included with the pdksh shell.
 */
static const char ichars[256] = {
	   0,  0x1,  0x2,  0x3,  0x4,  0x5,  0x6,  0x7,
	 0x8,  0x9,  0xa,  0xb,  0xc,  0xd,  0xe,  0xf,
	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
	0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
	0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
	0x40,  'a',  'b',  'c',  'd',  'e',  'f',  'g',
	 'h',  'i',  'j',  'k',  'l',  'm',  'n',  'o',
	 'p',  'q',  'r',  's',  't',  'u',  'v',  'w',
	 'x',  'y',  'z', 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
	0x60,  'a',  'b',  'c',  'd',  'e',  'f',  'g',
	 'h',  'i',  'j',  'k',  'l',  'm',  'n',  'o',
	 'p',  'q',  'r',  's',  't',  'u',  'v',  'w',
	 'x',  'y',  'z', 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
	0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
	0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
	0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
	0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
	0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
	0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
	0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
	0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
	0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
	0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
	0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
	0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
	0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
	0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
	0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
	0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
};

int
strcasecmp(s1, s2)
	const char *s1;
	const char *s2;
{
	const unsigned char *us1 = (const unsigned char *) s1;
	const unsigned char *us2 = (const unsigned char *) s2;

	while (ichars[*us1] == ichars[*us2++]) {
		if (*us1++ == '\0')
			return 0;
	}
	return ichars[*us1] - ichars[*--us2];
}

int
strncasecmp(s1, s2, n)
	const char *s1;
	const char *s2;
	size_t n;
{
	const unsigned char *us1 = (const unsigned char *) s1;
	const unsigned char *us2 = (const unsigned char *) s2;

	while (n != 0 && ichars[*us1] == ichars[*us2++]) {
		if (*us1++ == '\0')
			return 0;
		n--;
	}
	return n ? ichars[*us1] - ichars[*--us2] : 0;
}