pattern matching

[Jef Poskanzer]

In the referenced message, mhb at hcx.uucp (MARK H BOTNER) wrote:
}Can anybody help me with pattern matching?
}P.S. if you have any answer or a subroutine for me, please mail it to me.
}My address is:
}     mhb at cseg.uucp

That address is useless, so I'm posting this.  This is free software, no
copyright or trade secret restrictions whatsoever.
---
Jef

            Jef Poskanzer   jef at helios.ee.lbl.gov   ...well!pokey

/*
** Simple pattern matcher.  Does ?, *, and [], much like various shells.
**
** by Jef Poskanzer
*/

amatch( s, p )
register char *s, *p;
    {
    for ( ; *p != '\0'; p++, s++ )
	{
	if ( *p == '*' )
	    {
	    if ( *++p == '\0' )
		return 1;
	    for ( ; *s != '\0'; s++ )
		if ( amatch( s, p ) )
		    return 1;
	    return 0;
	    }
	if ( *s == '\0' )
	    return 0;
	if ( *p == '?' )
	    continue;
	if ( *p == '[' )
	    {
	    int negcc = 0, ccmatch = 0;
	    char prevc;
	    if ( *++p == '!' )
		{
		negcc = 1;
		p++;
		}
	    for ( ; *p != ']'; p++ )
		{
		if ( *p == '\0' )
		    {
		    fprintf( stderr, "amatch: missing ']'\n" );
		    return 0;
		    }
		if ( *p == '-' )
		    {
		    if ( prevc <= *s && *++p >= *s )
			ccmatch = 1;
		    }
		else if ( *p == *s )
		    ccmatch = 1;
		prevc = *p;
		}
	    if ( ( ccmatch && ! negcc ) || ( negcc && ! ccmatch ) )
		continue;
	    return 0;
	    }
	if ( *p != *s )
	    return 0;
	}
    return *s == '\0';
    }