Shell script to regenerate debian changelog from git log

git2dch.sh

#!/bin/sh

sudo apt-get install -y moreutils git-buildpackage

>debian/changelog
prevtag=initial
pkgname=`cat debian/control | grep '^Package: ' | sed 's/^Package: //'`
git tag -l v* | sort -V | while read tag; do
    (echo "$pkgname (${tag#v}) unstable; urgency=low\n"; git log --pretty=format:'  * %s' $prevtag..$tag; git log --pretty='format:%n%n -- %aN <%aE>  %aD%n%n' $tag^..$tag) | cat - debian/changelog | sponge debian/changelog
        prevtag=$tag
done

tag=`git tag -l v* | sort -V | tail -1`
[ `git log --exit-code $tag..HEAD | wc -l` -ne 0 ] && git-dch -s $tag -S --no-multimaint --nmu --ignore-branch --snapshot-number="'{:%Y%m%d%H%M%S}'.format(__import__('datetime').datetime.fromtimestamp(`git log -1 --pretty=format:%at`))"

sed -i 's/UNRELEASED/unstable/' debian/changelog

git commit -a -m 'regenerated debian changelog'