str.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>


#if __CRTL_VER <= 70000000

char *strdup (char *src)
{
    char *ptr;
    ptr = malloc (strlen(src)+1);
    if (ptr == NULL)
        return (ptr);
    strcpy (ptr, src);

    return(ptr);
}


/*
 * This array is designed for mapping upper and lower case letter
 * together for a case independent comparison.	The mappings are
 * based upon ascii character sequences.
 */
static char charmap[] = {
	'\000', '\001', '\002', '\003', '\004', '\005', '\006', '\007',
	'\010', '\011', '\012', '\013', '\014', '\015', '\016', '\017',
	'\020', '\021', '\022', '\023', '\024', '\025', '\026', '\027',
	'\030', '\031', '\032', '\033', '\034', '\035', '\036', '\037',
	'\040', '\041', '\042', '\043', '\044', '\045', '\046', '\047',
	'\050', '\051', '\052', '\053', '\054', '\055', '\056', '\057',
	'\060', '\061', '\062', '\063', '\064', '\065', '\066', '\067',
	'\070', '\071', '\072', '\073', '\074', '\075', '\076', '\077',
	'\100', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
	'\170', '\171', '\172', '\133', '\134', '\135', '\136', '\137',
	'\140', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
	'\170', '\171', '\172', '\173', '\174', '\175', '\176', '\177',
	'\200', '\201', '\202', '\203', '\204', '\205', '\206', '\207',
	'\210', '\211', '\212', '\213', '\214', '\215', '\216', '\217',
	'\220', '\221', '\222', '\223', '\224', '\225', '\226', '\227',
	'\230', '\231', '\232', '\233', '\234', '\235', '\236', '\237',
	'\240', '\241', '\242', '\243', '\244', '\245', '\246', '\247',
	'\250', '\251', '\252', '\253', '\254', '\255', '\256', '\257',
	'\260', '\261', '\262', '\263', '\264', '\265', '\266', '\267',
	'\270', '\271', '\272', '\273', '\274', '\275', '\276', '\277',
	'\300', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
	'\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
	'\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
	'\370', '\371', '\372', '\333', '\334', '\335', '\336', '\337',
	'\340', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
	'\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
	'\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
	'\370', '\371', '\372', '\373', '\374', '\375', '\376', '\377',
};

int strcasecmp(s1, s2)
	register char *s1, *s2;
{
	register char *cm = charmap;

	if ((s1 == 0) && (s2 == 0))
	    return(0);
	else
	    {
	    if (s1 == 0)
		return (-1);
	    else
		if (s2 == 0)
		    return (1);
	    }

	while (cm[(unsigned char) *s1] == cm[(unsigned char) *s2++])
		if (*s1++ == '\0')
			return(0);
	return(cm[(unsigned char) *s1] - cm[(unsigned char) *--s2]);
}

int strncasecmp(s1, s2, n)
	register char *s1, *s2;
	register int n;
{
	register char *cm = charmap;

	if (n <= 0)
	    return(0);

	if ((s1 == 0) && (s2 == 0))
	    return(0);
	else
	    {
	    if (s1 == 0)
		return (-1);
	    else
		if (s2 == 0)
		    return (1);
	    }

	while (--n >= 0 && cm[(unsigned char) *s1] == cm[(unsigned char) *s2++])
		if (*s1++ == '\0')
			return(0);
	return(n < 0 ? 0 : cm[(unsigned char) *s1] - cm[(unsigned char) *--s2]);
}

char *strcasestr(register char *string, register char *substring)
{
    register char *cm = charmap;
    char *a, *b;

    if ((string == NULL) || (substring == NULL))
	return (string);

    b = substring;

    if (*b == 0) {
        return string;
    }
    for ( ; *string != 0; string += 1) {
        if (cm[(unsigned char) *string] != cm[(unsigned char) *b]) {
            continue;
        }
        a = string;
        while (1) {
            if (*b == 0) {
                return string;
            }
            if (cm[(unsigned char) *a++] != cm[(unsigned char) *b++]) {
                break;
            }
        }
        b = substring;
    }
    return (char *) 0;
}

#endif /* __CRTL_VER <= 70000000 */