get-ppa-changelog.sh

#!/bin/sh

# adress, i.e.: http://ppa.launchpad.net/djcj/nightingale/ubuntu/pool/main/n/nightingale/nightingale-common_1.13+20141127-1~utopic_all.deb
adress=${1}

# source package name, i.e.: nightingale
srcpkg=${2}

# version string
version=$(basename ${adress} | cut -d '_' -f2)

# Maximum size of the *.debian.tar.* file.
# If the filesize exceeds, the file won't be downloaded.
debtarball_maxsize=800000


debtarball_info=$(wget -q -O - "$(dirname ${adress})/${srcpkg}_${version}.dsc" | grep ${srcpkg}_${version}.debian.tar. | head -n1)
test -z "$debtarball_info" && exit 0

debtarball=$(echo $debtarball_info | cut -d' ' -f3)
debtarball_size=$(echo $debtarball_info | cut -d' ' -f2)
test $debtarball_size -ge $debtarball_maxsize && exit 0

case $(echo $debtarball | tail -c4) in
    .xz) compression=J ;;
    bz2) compression=j ;;
    .gz) compression=z ;;
    *)
esac

cd /tmp && rm -rf debian
wget -q -O - "$(dirname ${adress})/${debtarball}" | tar xvf${compression} - >/dev/null
cat debian/changelog && rm -rf debian