implement fs.isfile and fs.isdirectory

lfs.c

@@ -114,6 +114,64 @@ fs_exists(lua_State *L)
 	return 1;
 }
 
+/***
+ * Returns true if the given path specifies a
+ * directory, or false if it does not.
+ *
+ * On error returns nil, an error message and a
+ * platform-dependent error code.
+ *
+ * @function isdirectory
+ * @usage
+if not fs.isdirectory("/usr") then
+    print("something's wrong")
+end
+ * @tparam string path The path to check.
+ */
+static int
+fs_isdirectory(lua_State *L)
+{
+	struct stat sb;
+	const char *path;
+
+	path = luaL_checkstring(L, 1);
+
+	if (stat(path, &sb) == -1)
+		return lfail(L);
+
+	lua_pushboolean(L, sb.st_mode & S_IFDIR);
+	return 1;
+}
+
+/***
+ * Returns true if the given path specifies a file,
+ * or false if it does not.
+ *
+ * On error returns nil, an error message and a
+ * platform-dependent error code.
+ *
+ * @function isfile
+ * @usage
+if not fs.isfile("/sbin/init") then
+    print("something's wrong")
+end
+ * @tparam string path The path to check.
+ */
+static int
+fs_isfile(lua_State *L)
+{
+	struct stat sb;
+	const char *path;
+
+	path = luaL_checkstring(L, 1);
+
+	if (stat(path, &sb) == -1)
+		return lfail(L);
+
+	lua_pushboolean(L, sb.st_mode & S_IFREG);
+	return 1;
+}
+
 /*
  * Taken from OpenBSD mkdir(1)
  * mkpath -- create directories.
@@ -323,6 +381,8 @@ fs_workdir(lua_State *L)
 static const luaL_Reg fslib[] = {
 	{"copy",        fs_copy},
 	{"exists",      fs_exists},
+	{"isdirectory", fs_isdirectory},
+	{"isfile",      fs_isfile},
 	{"mkdir",       fs_mkdir},
 	{"move",        fs_move},
 	{"rmdir",       fs_rmdir},