#! /bin/sh
set -e

usage()
{
    echo "Usage: $0 FILE"
    echo "Prints the version number from the control file of a package."
}

if [ $# -ne 1 ]
then
    usage
    exit 2
fi

file="$1"
dir="$(mktemp -d "version.XXXXXXXXXX")"
trap "rm -rf -- '$dir'" EXIT

# Too bad tar has no p action like ar does
ar p $1 control.tar.gz | tar -zxC "$dir" ./control
grep "^Version:" "$dir/control" | sed -e 's/Version: *//'

rm -rf -- "$dir"
trap - EXIT