Bash Alias: Make and Restore Backups

2025-02-04

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I often find myself needing to create temporary backups of files or directories. The way I usually do this is by appending its name with the date and a ".bak" extension. It can be tedious to do that over and over again, especially when I'm testing a program or script; I'd much rather automate backups with one command.

Today I put together a Bash alias to do just that:

function mkbak() {
    restoreBackup=0
    case "${1}" in
        -r|--restore) restoreBackup=1; shift; continue;;
        *) ;;
    esac
    if [ $restoreBackup -eq 1 ]; then
        for backup in "$@"; do
            [ -e "${backup}" ] && { rm -fr "${backup%_*}"; mv "${backup}" "${backup%_*}"; }
        done
    else
        for original in "$@"; do
            [ -f "${original}" ] && cp "${original}" "${original}_$(date +"%Y%m%d-%H%M%S").bak"
            [ -d "${original}" ] && { originalNoTrailingSlash="${original%"${original##*[!/]}"}"; cp -R "${original}" "${originalNoTrailingSlash}_$(date +"%Y%m%d-%H%M%S").bak"; }
        done
    fi
}

This alias can back up or restore multiple files or directories at once. The process of restoring a backup requires deleting the original first; otherwise `mv` behaves unexpectedly when restoring a directory.

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[Last updated: 2025-02-05]