match.c

/*  Copyright 1986-1992 Emmet P. Gray.
 *  Copyright 1996-1998,2001,2002,2008,2009 Alain Knaff.
 *  This file is part of mtools.
 *
 *  Mtools is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Mtools is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Mtools.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Do shell-style pattern matching for '?', '\', '[..]', and '*' wildcards.
 * Returns 1 if match, 0 if not.
 */

#include "sysincludes.h"
#include "mtools.h"


static int casecmp(wchar_t a, wchar_t b)
{
	return towupper((wint_t)a) == towupper((wint_t)b);
}

static int exactcmp(wchar_t a,wchar_t b)
{
	return a == b;
}


static int is_in_range(wchar_t ch, const wchar_t **p, int *reverse) {
	wchar_t first, last;
	int found=0;
	if (**p == '^') {
		*reverse = 1;
		(*p)++;
	} else
		*reverse=0;
	while( (first = **p) != ']') {
		if(!first)
			/* Malformed pattern, range not closed */
			return 0;
		if(*(++(*p)) == '-') {
			last = *(++(*p));				
			if(last==']') {
				/* Last "-" in range designates itself */
				if(ch == first || ch == '-')
					found = 1;
				break;
			}
			(*p)++;

			/* a proper range */
			if(ch >= first && ch <= last)
				found = 1;
		} else
			/* a Just one character */
			if(ch == first)
				found = 1;
	}
	return found;
}

static int parse_range(const wchar_t **p, const wchar_t *s, wchar_t *out,
		       int (*compfn)(wchar_t a, wchar_t b))
{
	int reverse;
	const wchar_t *p0 = *p;
	const wchar_t *p1 = *p;
	if(out)
		*out = *s;
	if(is_in_range(*s, p, &reverse))
		return 1 ^ reverse;
	if(compfn == exactcmp)
		return reverse;
	if(is_in_range((wchar_t)towlower((wint_t)*s), &p0, &reverse)) {
		if(out)
			*out = (wchar_t)towlower((wint_t)*s);
		return 1 ^ reverse;
	}
	if(is_in_range((wchar_t)towupper((wint_t)*s), &p1, &reverse)) {
		if(out)
			*out = (wchar_t)towupper((wint_t)*s);
		return 1 ^ reverse;
	}
	return reverse;
}


static int _match(const wchar_t *s, const wchar_t *p, wchar_t *out, int Case,
		  int length,
		  int (*compfn) (wchar_t a, wchar_t b))
{
	for (; *p != '\0' && length; ) {
		switch (*p) {
			case '?':	/* match any one character */
				if (*s == '\0')
					return(0);
				if(out)
					*(out++) = *s;
				break;
			case '*':	/* match everything */
				while (*p == '*' && length) {
					p++;
					length--;
				}

					/* search for next char in pattern */
				while(*s) {
					if(_match(s, p, out, Case, length,
						  compfn))
						return 1;
					if(out)
						*out++ = *s;
					s++;
				}
				continue;
			case '[':	 /* match range of characters */
				p++;
				length--;
				if(!parse_range(&p, s, out++, compfn))
					return 0;
				break;
			case '\\':	/* Literal match with next character */
				p++;
				length--;
				/* fall thru */
			default:
				if (!compfn(*s,*p))
					return(0);
				if(out)
					*(out++) = *p;
				break;
		}
		p++;
		length--;
		s++;
	}
	if(out)
		*out = '\0';

					/* string ended prematurely ? */
	if (*s != '\0')
		return(0);
	else
		return(1);
}


int match(const wchar_t *s, const wchar_t *p, wchar_t *out, int Case, int length)
{
	int (*compfn)(wchar_t a, wchar_t b);

	if(Case)
		compfn = casecmp;
	else
		/*compfn = exactcmp;*/
		compfn = casecmp;
	return _match(s, p, out, Case, length, compfn);
}