git-sparse-checkout

#!/bin/sh

# Author: K. Potamianos <karolos.potamianos@cern.ch>
# Date: 2016-IX-29

cmd=${1}
path=${2}

function usage() {
  echo "usage: git sparse-checkout add path"
  echo "       git sparse-checkout addpkg package_name"
  echo "       git sparse-checkout list"
  echo "       git sparse-checkout rm regex"
  echo "       git sparse-checkout rmpkg package_name"
  exit 1
}

function die() {
  echo "$@"
  exit 128
}


if test $# -lt 1
then
  usage
fi

if test "$cmd" != "list" -a $# -lt 2
then
  usage
fi

git_dir=$(git rev-parse --show-toplevel)/.git

pkg_path=

function get_sparse_checkout_file() {
  if test -d ${git_dir}
  then # It's the standard case (or git-new-workdir copy)
    echo ${git_dir}/info/sparse-checkout
  elif test -f ${git_dir}
  then # It's a worktree working copy
    echo `cat ${git_dir} | sed 's/gitdir: //'`/info/sparse-checkout 
  fi
}

# Check whether path exists in git-ls-files (otherwise it makes no sense to add it)
function check_path_in_repo() {
  git-ls-files | grep -m 1 '/^${path}/' && die "Error: ${path} not found in repository"
}

# Find 'package' in files known to git
function find_pkg() {
  pkg_path=`git ls-files | grep /${path}/ | sed "s@/${path}/.*@/${path}/@" | sort -u`
  #echo find_pkg: ${pkg_path}
  test -n "${pkg_path}" || die "Error: no pakage named ${path} found in repository."
}

function add_path() {
  paths="${@}"
  for path in ${paths}
  do
    grep -m 1 "^${path}\$" ${sparse_checkout_file} && die "Error: ${path} already in sparse-checkout file"
    check_path_in_repo
    echo ${path} >> ${sparse_checkout_file}
    test -n $verbose && echo "${path} added to sparse checkout"
  done

}

function rm_path() {
  paths="${@}"
  for path in ${paths}
  do
    grep "^${path}\$" ${sparse_checkout_file} > /dev/null || die "Error: ${path} not in sparse-checkout file"
    sed -i "\|^${path}\$|d" ${sparse_checkout_file}
    test -n $verbose && echo "${path} removed to sparse checkout"
  done
}

function list_paths() {
  echo "Content of sparse-checkout file:"
  cat ${sparse_checkout_file}
}

sparse_checkout_file=`get_sparse_checkout_file`

case ${cmd} in
 add)    add_path "${path}" ;;
 addpkg) find_pkg && add_path "${pkg_path}" ;;
 list)   list_paths;;
 rm)     rm_path "${path}" ;;
 rmpkg) find_pkg && rm_path "${pkg_path}" ;;
 *)      usage ;;
esac