fixed a makefile thing and added the thingy that does things

Makefile

@@ -2,13 +2,16 @@ CC = gcc
 CFLAGS = -Wall -Wextra -O2 -pipe
 TARGET = timetolocal
 SRC = $(wildcard *.c)
+OBJ = $(SRC:.c=.o)
 PREFIX = /usr/local
 
 all: $(TARGET)
 
 $(TARGET): $(OBJ)
-	@mkdir -p $(@D)
-	$(CC) $(CFLAGS) -o $(TARGET) $(SRC)
+	$(CC) $(CFLAGS) -o $(TARGET) $(OBJ)
+
+%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
 
 install: $(TARGET)
 	install -D $(TARGET) $(DESTDIR)$(PREFIX)/bin/$(notdir $(TARGET))
@@ -17,4 +20,7 @@ uninstall:
 	rm -f $(DESTDIR)$(PREFIX)/bin/$(notdir $(TARGET))
 
 clean:
-	rm -rf $(TARGET)
+	rm -f $(TARGET) $(OBJ)
+
+.PHONY: all install uninstall clean
+