add match_wildcard function (for vfs_next_dirent)

This was SVN commit r1383.

source/lib/lib.cpp

@@ -366,3 +366,56 @@ void base32(const int len, const u8* in, u8* out)
 	}
 }
 
+
+
+
+
+
+// case-insensitive check if string <s> matches the pattern <w>,
+// which may contain '?' or '*' wildcards. if so, return 1, otherwise 0.
+// idea from http://www.codeproject.com/string/wildcmp.asp .
+int match_wildcard(const char* s, const char* w)
+{
+	// saved position in both strings, used to expand '*':
+	// s2 is advanced until match.
+	// initially 0 - we abort on mismatch before the first '*'.
+	const char* s2 = 0;
+	const char* w2;
+
+	while(*s)
+	{
+		const int wc = *w;
+		if(wc == '*')
+		{
+			// wildcard string ended with * => match.
+			if(*++w == '\0')
+				return 1;
+
+			w2 = w;
+			s2 = s+1;
+		}
+		// match one character
+		else if(toupper(wc) == toupper(*s) || wc == '?')
+		{
+			w++;
+			s++;
+		}
+		// mismatched character
+		else
+		{
+			// no '*' found yet => mismatch.
+			if(!s2)
+				return 0;
+
+			// resume at previous position+1
+			w = w2;
+			s = s2++;
+		}
+	}
+
+	// strip trailing * in wildcard string
+	while(*w == '*')
+		w++;
+
+	return (*w == '\0');
+}

source/lib/lib.h

@@ -307,6 +307,10 @@ extern u16 fp_to_u16(double in);
 extern void base32(const int len, const u8* in, u8* out);
 
 
+// case-insensitive check if string <s> matches the pattern <w>,
+// which may contain '?' or '*' wildcards. if so, return 1, otherwise 0.
+extern int match_wildcard(const char* s, const char* w);
+
 
 // design goals:
 // fast (including startup time)