bash script to setup gitconfig

swc_setup_gitconfig.sh

#!/bin/env bash

# Script to clean and recover git configs before teaching.
# Based on script example from
#          https://dbwebb.se/kunskap/create-bash-script-with-options-commands-and-arguments

SCRIPT=$( basename "$0" )
VERSION="0.1"
BACKUP_PATTERN=".${USER}_gitconfig"
HOURS=6

function usage
{
    local txt=(
"Utility ${SCRIPT} for preparing and recovering the setup for a Carpentries git workshop."
"Usage: $SCRIPT [options] <command> [arguments]"
""
"Command:"
"  clean                Back-up current configuration and creates empty .gitconfig."
"  recover [remove]     Loads the latest back-up back in place ('remove' removes the backup)."
""
"Options:"
"  --help, -h     Print help."
"  --version, -v  Print version."
    )

    printf "%s\n" "${txt[@]}"
}

function badUsage
{
    local message="$1"
    local txt=(
"For an overview of the command, execute:"
"$SCRIPT --help"
    )

    [[ $message ]] && echo "$message"

    printf "%s\n" "${txt[@]}"
}

function version
{
    local txt=(
"$SCRIPT version $VERSION"
    )

    printf "%s\n" "${txt[@]}"
}

function app-clean
{
    local now
    now=$(date +"%Y%m%d_%H%M")
    mv ~/.gitconfig ~/"${BACKUP_PATTERN}_${now}"
    git config --global user.name "Vlad Dracula"
    git config --global user.email "vlad@tran.sylvan.ia"

}

function find_latest
{
    local pattern="$1"
    local files_match
    mapfile -t files_match < <(find ~/ -maxdepth 1 -type f -iname "*${pattern}_*" | sort -r)

    echo "${files_match[@]}"
}

function dates_difference
{
    local file_dates
    local dates
    local now_s
    file_dates=$( echo "$1" | sed 's/.*\([0-9]\{8\}_[0-9]\{4\}\)/\1/' | sed 's/_/ /')
    dates=$(date -d "${file_dates}" "+%s")
    now_s=$(date +"%s")
    echo $(( (now_s - dates) / 3600 ))

}

function app-recover
{
    local remove="$1"
    local force="${2:-FALSE}"
    local list_files
    list_files=$(find_latest "${BACKUP_PATTERN}")

    diff_now=$(dates_difference "${list_files[0]}")
    if (( diff_now > HOURS )); then
        if [ "$force" != "-f" ]; then
            echo "WARNING: The Backup is older than ${HOURS} hours (${diff_now}). Use '-f' to force its recovery"
            echo "         Run, cat ${list_files[0]} to see its content"
            exit 1
        else
            echo "WARNING: Overwriting file with a file older than ${HOURS} hours (${diff_now})."
        fi
    fi

    if [ "$remove" == "remove" ]; then
        action="mv"
    else
        action="cp"
    fi

    ${action} "${list_files[0]}" ~/.gitconfig

}




while (( $# ))
do
    case "$1" in

        --help | -h)
            usage
            exit 0
        ;;

        --version | -v)
            version
            exit 0
        ;;

        clean \
        | recover)
            command="$1"
            shift
            app-"$command" "$@"
            exit 0
            ;;

        *)
            badUsage "Option/command not recognised."
            exit 1
        ;;

    esac
done

badUsage
exit 1