Script to download an APT package and view its control file

apt-examine.sh

#!/bin/bash
set -euo pipefail

TMPDIR=""

function cleanup {
    [[ ! -z $TMPDIR ]] && rm -r "$TMPDIR"
}
trap cleanup EXIT

if (( $# == 0 )); then
    echo "usage: apt-examine <package>"
    echo "Shows the .deb control file from a package."
    exit 1
else
    TMPDIR="$(mktemp --directory)"
    cd "$TMPDIR"
    apt download $1 1>&2
    ar -p *.deb control.tar.gz | tar -zxC . ./control -O
fi