add example Makefile

README.md

@@ -26,4 +26,5 @@ Example usage:
            f2c myapp.f
            gcc -o myapp myapp.c -lf2c
 
-The buildpack will detect your app as FORTRAN-77 if it has the file `Makefile` in the root. It will then run `make` to compile the app.
+The buildpack will detect your app as FORTRAN-77 if it has the file `Makefile` in the root.
+It will then run `make` to compile the app (see examples/Makefile for a template).

examples/Makefile

@@ -0,0 +1,19 @@
+CFLAGS=-c
+LDFLAGS=-L$(F2CLIB_DIR) -lf2c -lm
+
+EXECUTABLE=myapp
+SOURCES=myapp.f
+OBJECTS=$(SOURCES:.f=.o)
+INTERMEDIATES=$(SOURCES:.f=.c)
+
+all: $(SOURCES) $(EXECUTABLE)
+
+$(EXECUTABLE): $(OBJECTS)
+	$(CC) $(OBJECTS) -o $@ $(LDFLAGS)
+
+.f.o:
+	f2c $<
+	$(CC) $(CFLAGS) $(<:.f=.c) -o $@
+
+clean:
+	rm -f $(EXECUTABLE) $(OBJECTS) $(INTERMEDIATES)