diff -up sjinn/Makefile.orig sjinn/Makefile
--- sjinn/Makefile.orig	2011-04-18 16:59:35.023065359 -0400
+++ sjinn/Makefile	2011-04-18 17:01:10.385873158 -0400
@@ -7,6 +7,7 @@ INSTALL=/usr/bin/install -c
 DEPEND=/usr/X11R6/bin/makedepend
 TARGET=rs232
 S_LINK=sjinn
+DESTDIR=
 
 prefix=/usr/local
 exec_prefix=${prefix}
@@ -26,18 +27,18 @@ rs232ctl.o: rs232ctl.c rs232.h
 	$(CC) -c rs232ctl.c  $(CFLAGS) $(INC)
 
 install:
-	$(INSTALL) $(TARGET) ${bindir}
-	rm -f ${bindir}/$(S_LINK)
-	ln -s ${bindir}/$(TARGET) ${bindir}/$(S_LINK)
-	$(INSTALL) -m 0644 $(TARGET).1.gz ${mandir}/$(TARGET).1.gz
-	rm -f ${mandir}/$(S_LINK).1.gz
-	ln -s ${mandir}/$(TARGET).1.gz ${mandir}/$(S_LINK).1.gz
+	$(INSTALL) $(TARGET) $(DESTDIR)/${bindir}/$(TARGET)
+	rm -f $(DESTDIR)/${bindir}/$(S_LINK)
+	ln -s ${bindir}/$(TARGET) $(DESTDIR)/${bindir}/$(S_LINK)
+	$(INSTALL) -m 0644 $(TARGET).1.gz $(DESTDIR)/${mandir}/$(TARGET).1.gz
+	rm -f $(DESTDIR)/${mandir}/$(S_LINK).1.gz
+	ln -s ${mandir}/$(TARGET).1.gz $(DESTDIR)/${mandir}/$(S_LINK).1.gz
 
 uninstall:
-	rm -f ${bindir}/$(S_LINK)
-	rm -f ${bindir}/$(TARGET)
-	rm -f ${mandir}/$(S_LINK).1.gz
-	rm -f ${mandir}/$(TARGET).1.gz
+	rm -f $(DESTDIR)/${bindir}/$(S_LINK)
+	rm -f $(DESTDIR)/${bindir}/$(TARGET)
+	rm -f $(DESTDIR)/${mandir}/$(S_LINK).1.gz
+	rm -f $(DESTDIR)/${mandir}/$(TARGET).1.gz
 
 clean:
 	rm -f $(TARGET) *.o