git-untouch

#!/bin/sh
#
# git-untouch - undo git-touch
#
# Copyright (c) 2012-2015 Akinori MUSHA
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#

usage () {
    cat <<EOS >&2
usage: git untouch <filename>...

    -v, --verbose         be verbose
    -n, --dry-run         dry run
    -k                    skip any error
EOS
    exit 129
}

exit_status=

may_exit () {
    exit_status=${1:-$?}
    [ -z "$opt_k" ] && exit $exit_status
}

[ $# -gt 0 ] || usage

while getopts 'vnk-:' opt; do
    case "$opt" in
        [vnk])
            eval "opt_$opt=t"
            [ "$opt" = n ] && opt_v=t
            ;;
        -)
            case "$OPTARG" in
                verbose)
                    opt_v=t
                    ;;
                dry-run)
                    opt_n=t
                    opt_v=t
                    ;;
                *)
                    echo "Illegal option --$OPTARG" >&2
                    exit 64
                    ;;
            esac
            ;;
        *)
            exit 64
            ;;
    esac
done

shift $((OPTIND - 1))

for file; do
    if [ -L "$file" -o ! -f "$file" ]; then
        echo "Not a regular file: $file" >&2
        may_exit 1
    elif ! git status --porcelain -- "$file" 2>/dev/null | grep -q '^A'; then
        echo "Not a new file: $file" >&2
        may_exit 1
    elif [ $(git show :"$file" | wc -c) -gt 0 ]; then
        echo "Index not empty: $file" >&2
        may_exit 1
    elif [ -s "$file" ]; then
        [ -z "$opt_v" ] || echo "Unstaging $file"
        [ -z "$opt_n" ] || continue
        git reset -- "$file" >/dev/null
    else
        [ -z "$opt_v" ] || echo "Removing $file"
        [ -z "$opt_n" ] || continue
        git reset -- "$file" >/dev/null
        rm -- "$file" || may_exit "$?"
        rmdir -p "$(cd "$(dirname "$file")" && pwd -P)" 2>/dev/null || :
    fi
done

exit $exit_status