/* match.c: pattern matching routines */#include "rc.h"static int rangematch(char *, char);enum { RANGE_FAIL = -1, RANGE_ERROR = -2 };/* match() matches a single pattern against a single string. */extern bool match(char *p, char *m, char *s) {	int i, j;	if (m == NULL)		return streq(p, s);	i = 0;	while (1) {		if (p[i] == '\0')			return *s == '\0';		else if (m[i]) {			switch (p[i++]) {			case '?':				if (*s++ == '\0')					return FALSE;				break;			case '*':				while (p[i] == '*' && m[i] == 1)	/* collapse multiple stars */					i++;				if (p[i] == '\0') 	/* star at end of pattern? */					return TRUE;				while (*s != '\0')					if (match(p + i, m + i, s++))						return TRUE;				return FALSE;			case '[':				if (*s == '\0')					return FALSE;				switch (j = rangematch(p + i, *s)) {				default:					i += j;					break;				case RANGE_FAIL:					return FALSE;				case RANGE_ERROR:					if (*s != '[')						return FALSE;				}				s++;				break;			default:				panic("bad metacharacter in match");				/* NOTREACHED */				return FALSE; /* hush up gcc -Wall */			}		} else if (p[i++] != *s++)			return FALSE;	}}/*   From the ed(1) man pages (on ranges):	The `-' is treated as an ordinary character if it occurs first	(or first after an initial ^) or last in the string.	The right square bracket does not terminate the enclosed string	if it is the first character (after an initial `^', if any), in	the bracketed string.   rangematch() matches a single character against a class, and returns   an integer offset to the end of the range on success, or -1 on   failure.*/static int rangematch(char *p, char c) {	char *orig = p;	bool neg = (*p == '~');	bool matched = FALSE;	if (neg)		p++;	if (*p == ']') {		p++;		matched = (c == ']');	}	for (; *p != ']'; p++) {		if (*p == '\0')			return RANGE_ERROR;	/* bad syntax */		if (p[1] == '-' && p[2] != ']') { /* check for [..-..] but ignore [..-] */			if (c >= *p)				matched |= (c <= p[2]);			p += 2;		} else {			matched |= (*p == c);		}	}	if (matched ^ neg)		return p - orig + 1; /* skip the right-bracket */	else		return RANGE_FAIL;}