--- ./Makefile.orig	1999-02-12 15:28:35.000000000 -0200
+++ ./Makefile	2014-02-16 15:38:19.000000000 -0300
@@ -1,11 +1,10 @@
 # Makefile for gexpr
 # Last updated: 10 February 1999
 
-CC	= gcc
-OPTS	= -s -O2 -Wall
+OPTS	= ${CFLAGS} ${CPPFLAGS}
 OBJS	= eval.o read_token.o commands.o output.o errors.o gexpr.o 
 GEXPR	= gexpr
-LIBS	= -lm
+LIBS	= -lm ${LDFLAGS}
 
 all: $(GEXPR)
 
@@ -31,8 +30,8 @@
 	$(CC) $(OPTS) -c gexpr.c
 
 install:
-	cp -f gexpr /usr/local/bin;
-	cp -f gexpr.1 /usr/local/man/man1
+	install -s gexpr ${DESTDIR}/usr/local/bin;
+	install gexpr.1 ${DESTDIR}/usr/local/share/man/man1
 	
 clean:
 	rm -f *.o core