/* 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; }