--- Makefile.orig	2013-11-16 11:45:54.000000000 +0800
+++ Makefile	2013-11-16 11:46:33.000000000 +0800
@@ -19,12 +19,12 @@ VERSION = 4.0
 
 VPATH = ../src
 
-DESTROOT =
-DESTPATH = $(DESTROOT)/usr/local/rtty
+DESTROOT = ${PREFIX}
+DESTPATH = $(DESTROOT)/rtty
 DESTBIN = $(DESTPATH)/bin
 
 #CC = cc
-CDEBUG = -O
+#CDEBUG = -O
 #
 # use -U to undefine, -D to define
 #	DEBUG		include code to help debug this software
@@ -37,7 +37,7 @@ CDEBUG = -O
 CDEFS = -DDEBUG -UWANT_TCPIP -UNEED_BITYPES_H -UNEED_INET_ATON \
 	-UNO_SOCKADDR_LEN -UNO_HSTRERROR
 #
-CFLAGS = $(CDEBUG) $(CDEFS) -I/usr/local/include
+CFLAGS += $(CDEBUG) $(CDEFS)
 LIBS = -lcrypt
 #(if WANT_TCPIP defined and this isn't in your libc)
 # -lresolv
@@ -59,15 +59,15 @@ kit:; shar README Makefile *.c *.h *.sh 
 bin.tar:; tar cf bin.tar $(ALL)
 
 install: $(ALL) Makefile
-	-set -x; test -d $(DESTPATH) || mkdir $(DESTPATH)
+	-set -x; test -d $(DESTDIR)$(DESTPATH) || mkdir $(DESTDIR)$(DESTPATH)
 	-set +e -x; for x in bin dev sock log pid opt out; do \
-		test -d $(DESTPATH)/$$x || mkdir $(DESTPATH)/$$x; \
+		test -d $(DESTDIR)$(DESTPATH)/$$x || mkdir $(DESTDIR)$(DESTPATH)/$$x; \
 	done
 	set -x; for x in $(BINARY); do \
-		install -c -m 111 $$x $(DESTBIN)/$$x; \
+		install -c -s -m 111 $$x $(DESTDIR)$(DESTBIN)/$$x; \
 	done
 	set -x; for x in $(SCRIPT); do \
-		install -c -m 555 $$x $(DESTBIN)/$$x; \
+		install -c -m 555 $$x $(DESTDIR)$(DESTBIN)/$$x; \
 	done
 
 ttysrv: ttysrv.o ttyprot.o connutil.o misc.o version.o