#! /bin/sh -e
-VERSION=$1
-MAJOR=`expr $1 : '\(^[0-9]*\.[0-9]*\)'`
+if [ -z "$1" ]; then
+ echo >&2 "No version specified, stopping."
+ exit 1
+fi
+
+VERSION="$1"
+MAJOR="${1%.*}"
rm -f linux
-wget -c ftp://ftp.kernel.org/pub/linux/kernel/v$MAJOR/linux-$VERSION.tar.bz2
-tar xjvf linux-$VERSION.tar.bz2
-rm -f linux-$VERSION.tar.bz2
-mv linux linux-$VERSION
-ln -s linux-$VERSION linux
+wget -c "ftp://ftp.kernel.org/pub/linux/kernel/v$MAJOR/linux-$VERSION.tar.bz2"
+tar xjvf "linux-$VERSION.tar.bz2"
+mv linux "linux-$VERSION"
+ln -s "linux-$VERSION" linux