Add glob matching

src/fglob.nim

+{.compile: "glob_matching.c".}
+
+proc g_match(s, p: cstring): cint {.importc.}
+
+echo g_match("abcdef", "bc")
\ No newline at end of file

src/glob_matching.c

+/*
+ * robust glob pattern matcher
+ * ozan s. yigit/dec 1994
+ * public domain
+ *
+ * glob patterns:
+ *	*	matches zero or more characters
+ *	?	matches any single character
+ *	[set]	matches any character in the set
+ *	[!set]	matches any character NOT in the set
+ *		where a set is a group of characters or ranges. a range
+ *		is written as two characters seperated with a hyphen: a-z denotes
+ *		all characters between a to z inclusive.
+ *	[-set]	set matches a literal hypen and any character in the set
+ *	[]set]	matches a literal close bracket and any character in the set
+ *
+ *	char	matches itself except where char is '*' or '?' or '['
+ *	\char	matches char, including any pattern character
+ *
+ * examples:
+ *	a*c		ac abc abbc ...
+ *	a?c		acc abc aXc ...
+ *	a[a-z]c		aac abc acc ...
+ *	a[-a-z]c	a-c aac abc ...
+ *
+ */
+
+#ifndef NEGATE
+#define NEGATE	'!'			/* std cset negation char */
+#endif
+
+#define TRUE    1
+#define FALSE   0
+
+int g_match (const char *str, const char *p)
+{
+	int negate;
+	int match;
+	int c;
+
+	while (*p) {
+		if (!*str && *p != '*')
+			return FALSE;
+
+		switch (c = *p++) {
+
+		case '*':
+			while (*p == '*')
+				p++;
+
+			if (!*p)
+				return TRUE;
+
+			if (*p != '?' && *p != '[' && *p != '\\')
+				while (*str && *p != *str)
+					str++;
+
+			while (*str) {
+				if (g_match (str, p))
+					return TRUE;
+				str++;
+			}
+			return FALSE;
+
+		case '?':
+			if (*str)
+				break;
+			return FALSE;
+/*
+ * set specification is inclusive, that is [a-z] is a, z and
+ * everything in between. this means [z-a] may be interpreted
+ * as a set that contains z, a and nothing in between.
+ */
+		case '[':
+			if (*p != NEGATE)
+				negate = FALSE;
+			else {
+				negate = TRUE;
+				p++;
+			}
+
+			match = FALSE;
+
+			while (!match && (c = *p++)) {
+				if (!*p)
+					return FALSE;
+				if (*p == '-') {	/* c-c */
+					if (!*++p)
+						return FALSE;
+					if (*p != ']') {
+						if (*str == c || *str == *p ||
+						    (*str > c && *str < *p))
+							match = TRUE;
+					}
+					else {		/* c-] */
+						if (*str >= c)
+							match = TRUE;
+						break;
+					}
+				}
+				else {			/* cc or c] */
+					if (c == *str)
+						match = TRUE;
+					if (*p != ']') {
+						if (*p == *str)
+							match = TRUE;
+					}
+					else
+						break;
+				}
+			}
+
+			if (negate == match)
+				return FALSE;
+/*
+ * if there is a match, skip past the cset and continue on
+ */
+			while (*p && *p != ']')
+				p++;
+			if (!*p++)	/* oops! */
+				return FALSE;
+			break;
+
+		}
+		str++;
+	}
+
+	return !*str;
+}