git-parent

#!/bin/bash

# Finds the direct parent of the current branch in git.

usage() {
    (
        echo "usage: ${0##*/} [-h|--help] [-r]"
        echo "Finds the direct parent of the current branch in git."
        echo
        echo "options:"
        (
            echo "    -h, --help: show usage help"
        ) | column -ts:
    ) >&2
    exit 1
}

if echo "$*" | grep -Eq -- '--help\b|-h\b'; then
    usage
fi

while getopts "r" opt; do
    case "$opt" in
    *) usage ;;
    esac
done
shift $((OPTIND - 1))

vbc=$(git rev-parse --abbrev-ref HEAD)
vbc_col=$(($(git show-branch | grep '^[^\[]*\*' | head -1 | cut -d'*' -f1 | wc -c) - 1))
swimming_lane_start_row=$(($(git show-branch | grep -n "^[\\-]*$" | cut -d: -f1) + 1))
git show-branch | tail -n +$swimming_lane_start_row | grep -v "^[^\\[]*\\[$vbc" | grep "^.\\{$vbc_col\\}[^ ]" | head -n1 | sed 's/.*\[\(.*\)\].*/\1/' | sed 's/[\^~].*//'