static char rcsid[] = "$Id: wildmat.c,v 1.1 1992/09/06 19:31:32 mike Exp $";

/* $Log: wildmat.c,v $
 * Revision 1.1  1992/09/06  19:31:32  mike
 * Initial revision
 *
 */

/*
**  Do shell-style pattern matching for ?, \, [], and * characters.
**  Might not be robust in face of malformed patterns; e.g., "foo[a-"
**  could cause a segmentation violation.  It is 8bit clean.
**
**  Written by Rich $alz, mirror!rs, Wed Nov 26 19:03:17 EST 1986.
**  Rich $alz is now <rsalz@bbn.com>.
**  Special thanks to Lars Mathiesen <thorinn@diku.dk> for the ABORT code.
**  This can greatly speed up failing wildcard patterns.  For example:
**	pattern: -*-*-*-*-*-*-12-*-*-*-m-*-*-*
**	text 1:	 -adobe-courier-bold-o-normal--12-120-75-75-m-70-iso8859-1
**	text 2:	 -adobe-courier-bold-o-normal--12-120-75-75-X-70-iso8859-1
**  Text 1 matches with 51 calls, while text 2 fails with 54 calls.  Without
**  the ABORT, then it takes 22310 calls to fail.  Ugh.
**
**  C Durland added:
**    MS-DOS uses \ for path, so do nothing for \ in that case.
**    Put man page at the end of this file.
*/

#include "os.h"		/* only used for MSDOZ, ATARI --CD */

#define TRUE		1
#define FALSE		0
#define ABORT		-1

#define NEGATE_CLASS	'^'

/* Forward declaration. */
static int	DoMatch();

/*
**  See if the text matches the p, which has an implied leading asterisk.
*/
static int
Star(text, p)
    register char	*text;
    register char	*p;
{
    register int	ret;

    do
	ret = DoMatch(text++, p);
    while (ret == FALSE);
    return ret;
}


/*
**  Match text and p, return TRUE, FALSE, or ABORT.
*/
static int
DoMatch(text, p)
    register char	*text;
    register char	*p;
{
    register int 	 last;
    register int 	 matched;
    register int 	 reverse;

    for ( ; *p; text++, p++) {
	if (*text == '\0' && *p != '*')
	    return ABORT;
	switch (*p) {
#if !(MSDOZ || ATARI)		/* blame those bozos at Microsoft */
	case '\\':
	    /* Literal match with following character. */
	    p++;
	    /* FALLTHROUGH */
#endif
	default:
	    if (*text != *p)
		return FALSE;
	    continue;
	case '?':
	    /* Match anything. */
	    continue;
	case '*':
	    /* Trailing star matches everything. */
	    return *++p ? Star(text, p) : TRUE;
	case '[':
	    if (reverse = p[1] == NEGATE_CLASS)
		/* Inverted character class. */
		p++;
	    for (last = 0400, matched = FALSE; *++p && *p != ']'; last = *p)
		/* This next line requires a good C compiler. */
		if (*p == '-' ? *text <= *++p && *text >= last : *text == *p)
		    matched = TRUE;
	    if (matched == reverse)
		return FALSE;
	    continue;
	}
    }

    return *text == '\0';
}


/*
**  User-level routine.  Returns TRUE or FALSE.
*/
int
wildmat(text, p)
    char	*text;
    char	*p;
{
    return DoMatch(text, p) == TRUE;
}



#ifdef	TEST
#include <stdio.h>

/* Yes, we use gets not fgets.  Sue me. */
extern char	*gets();


main()
{
    char	 p[80];
    char	 text[80];

    printf("Wildmat tester.  Enter pattern, then strings to test.\n");
    printf("A blank line gets prompts for a new pattern; a blank pattern\n");
    printf("exits the program.\n\n");

    for ( ; ; ) {
	printf("Enter pattern:  ");
	(void)fflush(stdout);
	if (gets(pattern) == NULL || pattern[0] == '\n')
	    break;
	for ( ; ; ) {
	    printf("Enter text:  ");
	    (void)fflush(stdout);
	    if (gets(text) == NULL)
		exit(0);
	    if (text[0] == '\0')
		/* Blank line; go back and get a new pattern. */
		break;
	    printf("      %s\n", wildmat(text, pattern) ? "YES" : "NO");
	}
    }

    exit(0);
    /* NOTREACHED */
}
#endif	/* TEST */



#if 0		/* the man page */

 WILDMAT(3)                                                       WILDMAT(3)


 NAME
      wildmat - perform shell-style wildcard matching

 SYNOPSIS
      int
      wildmat(text, pattern)
          char       *text;
          char       *pattern;

 DESCRIPTION
      Wildmat compares the text against the pattern and returns non-zero if
      the pattern matches the text.  The pattern is interpreted similar to
      shell filename wildcards, and not as a full regular expression such as
      those handled by the grep(1) family of programs or the regex(3) or
      regexp(3) set of routines.

      The pattern is interpreted according to the following rules:

      \x   Turns off the special meaning of x and matches it directly; this
           is used mostly before a question mark or asterisk, and is not
           valid inside square brackets.

      ?    Matches any single character.

      *    Matches any sequence of zero or more characters.

      [x...y]
           Matches any single character specified by the set x...y, where
           any character other than minus sign or close bracket may appear
           in the set.  A minus sign may be used to indicate a range of
           characters.  That is, [0-5abc] is a shorthand for [012345abc].
           More than one range may appear inside a character set; [0-9a-zA-
           Z._] matches almost all of the legal characters for a host name.

      [^x...y]
           This matches any character not in the set x...y, which is
           interpreted as described above.

 BUGS
      There is no way to specify a minus sign in a character range.

 HISTORY
      Written by Rich $alz <rsalz@bbn.com> in 1986, and posted to Usenet
      several times since then, most notably in comp.sources.misc in March,
      1991.
      Lars Mathiesen <thorinn@diku.dk> enhanced the multi-asterisk failure
      mode in early 1991.

 SEE ALSO
      grep(1), regex(3), regexp(3).


                                    - 1 -       Formatted:  January 17, 1992

#endif