Update

src/filesys/fsutil.h

+#ifndef FILESYS_FSUTIL_H
+#define FILESYS_FSUTIL_H
+
+void fsutil_ls (char **argv);
+void fsutil_cat (char **argv);
+void fsutil_rm (char **argv);
+void fsutil_extract (char **argv);
+void fsutil_append (char **argv);
+
+#endif /* filesys/fsutil.h */