Makefile: add PREFIX support

This allows users to easily install to /usr/local, instead of forcing
them to change 3 variables.

Signed-off-by: Florian Pritz <bluewind@xinu.at>

1 files changed, 4 insertions, 3 deletions

diff --git a/Makefile b/Makefile
index 238de2b..e10b011 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,8 @@
 VERSION:=$(shell git describe --dirty | sed 's/^v//; s/-/./g')
-MANDIR=/usr/share/man
-BINDIR=/usr/bin
-LIBDIR=/usr/lib
+PREFIX=/usr
+MANDIR=$(PREFIX)/share/man
+BINDIR=$(PREFIX)/bin
+LIBDIR=$(PREFIX)/lib
 MY_LIBDIR=$(LIBDIR)/fb-client
 CC=cc
 CFLAGS:=-std=c99 -O2 -Wall -Wextra -pedantic $(CFLAGS)