strcasecmp.c

/*
 * String manipulation routines
 */
/* (C) Copyright 1993,1994 by Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without
 * fee, provided that the above copyright notice appear in all copies
 * and that both that copyright notice and this permission notice
 * appear in supporting documentation, and that the name of Carnegie
 * Mellon University not be used in advertising or publicity
 * pertaining to distribution of the software without specific,
 * written prior permission.  Carnegie Mellon University makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 *
 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
 * FOR ANY SPECIAL, 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 <ctype.h>

static unsigned char upcase[256] = {
    0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
   16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
  ' ','!','"','#','$','%','&', 39,'(',')','*','+',',','-','.','/',
  '0','1','2','3','4','5','6','7','8','9',':',';','<','=','>','?',
  '@','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','[', 92,']','^','_',
  '`','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','{','|','}','~',127,
  128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
  144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,
  160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,
  176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,
  192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,
  208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
  224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,
  240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255};

#define UPC(x) (upcase[(unsigned char)(x)])

/*
 * Same as strcmp, but case-insensitive.
 */
int
strcasecmp(register char *s1, register char *s2)
{
    register char c1;
    while ((c1 = *s1) && UPC(c1) == UPC(*s2)) {
	s1++;
	s2++;
    }
    return UPC(c1) - UPC(*s2);
}

/*
 * Same as strncmp, but case-insensitive.
 */
int
strncasecmp(register char *s1, register char *s2, int n)
{
    register char c1;
    while (n-- && (c1 = *s1) && UPC(c1) == UPC(*s2)) {
	s1++;
	s2++;
    }
    if (n == -1) return 0;
    return UPC(c1) - UPC(*s2);
}