git-version-gen

#!/bin/sh

GVF=version.m4

if test -r $GVF; then
	VC=$(sed -e 's/m4_define(\[GIT_VERSION], \[//' <$GVF)
		VC=$(echo $VC | sed -e 's/\])//')
else
	VC=unset
fi

VN=$(./git-version)

test "$VN" = "$VC" || {
	echo >&2 "GIT_VERSION = $VN"
	echo "m4_define([GIT_VERSION], [$VN])" >$GVF
	exit 0
}