Use @ for input file variable replacement

Author: jcrd

Makefile

@@ -10,7 +10,7 @@ MANPAGE = auto-inhibit.1
 all: auto-inhibit $(MANPAGE)
 
 auto-inhibit: auto-inhibit.in
-	sed -e "s/VERSION=/VERSION=$(VERSION)/" auto-inhibit.in > auto-inhibit
+	sed -e "s/@VERSION/$(VERSION)/" auto-inhibit.in > auto-inhibit
 	chmod +x auto-inhibit
 
 $(MANPAGE): man/$(MANPAGE).pod

auto-inhibit.in

@@ -4,7 +4,7 @@
 
 set -eu
 
-readonly VERSION=
+readonly VERSION=@VERSION
 
 readonly CONFIG="${AUTO_INHIBIT_CONF:-/etc/auto-inhibit.conf}"
 readonly INHIBITOR="${AUTO_INHIBITOR:-$(command -v auto-inhibit)}"