giver_tarball

#!/bin/sh
# giver_tarball (create versioned tarballs from git trees)
# by ponce <matteo.bernardini@gmail.com>

# This program is free software. It comes without any warranty, to
# the extent permitted by applicable law. You can redistribute it
# and/or modify it under the terms of the WTFPL, Version 2, as
# published by Sam Hocevar. For more details, see
# http://www.wtfpl.net/txt/copying/

# This shell script uses the following binaries:
# git, head, cut, awk, sed, xz, md5sum

# Example use:
# Clone your git tree and move in the cloned folder. Launch
#   SRCNAM=name_of_the_sources /path/to/giver_tarball
# a tarball with of the tree of the latest version of the branch
# you're in will be created in /tmp

# Are we in a git tree?
if [ "$( git log 2>&1 | head -1 | cut -d: -f1 )" = "fatal" ]; then
  echo "this is not a git repository."
  exit 1
fi

# OUTPUT is set to /tmp if not else specified
OUTPUT=${OUTPUT:-/tmp}

# The name of the tarball is desumed by the remote repository name.
# You can override also this specifying SRCNAM (better).
REMOTEGIT=$( git remote -v | grep fetch | cut -d\  -f1 | awk -F/ '{print $NF}' )
SRCNAM=${SRCNAM:-"$REMOTEGIT"}

# Form a string usable for versioning a tarball.
# Running this in a git tree will output a string
# composed by the date, an underscore and the first
# 7 digit of the commit id of the active branch.
COMMIT=$( git log -1 | head -1 | cut -c 8-14 )
TODAY=$( git log -1 --date=short | grep ^Date | awk '{print $2}' | sed 's/-//g' )

# The branch is extracted from git status
BRANCH=$( git status | head -1 | cut -d\  -f4 )

# Some output
echo "creating tarball from $SRCNAM sources, with version ${TODAY}_${COMMIT}"
echo "$OUTPUT/$SRCNAM-${TODAY}_${COMMIT}.tar.xz"

# Actually create the tarball
git archive --prefix=$SRCNAM-${TODAY}_${COMMIT}/ $BRANCH | xz -c -z \
  > $OUTPUT/$SRCNAM-${TODAY}_${COMMIT}.tar.xz

# Calculate the md5sum
( cd $OUTPUT
md5sum $SRCNAM-${TODAY}_${COMMIT}.tar.xz > $SRCNAM-${TODAY}_${COMMIT}.tar.xz.md5 )