sh/shrc.d/bd.sh


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# Move back up the directory tree to the first directory matching the name
bd() {

    # Check argument count; default to ".."
    case $# in
        0) set -- .. ;;
        1) ;;
        *)
            printf >&2 'bd(): Too many arguments\n'
            return 2
    esac

    # Look at argument given; default to going up one level
    case $1 in

        # If it has a leading slash or is . or .., don't touch the arguments
        /*|.|..) ;;

        # Otherwise, we'll try to find a matching ancestor and then shift the
        # initial request off the argument list
        *)

            # Push the current directory onto the stack
            set -- "${1%/}" "$PWD"

            # Keep chopping at the current directory until it's empty or it
            # matches the request
            while set -- "$1" "${2%/*}" ; do
                case $2 in
                    */"$1") break ;;
                    */*) ;;
                    *)
                        printf >&2 'bd(): No match\n'
                        return 1
                        ;;
                esac
            done

            # If the first argument ended up empty, we have no match
            shift
            ;;
    esac

    # We have a match; try and change into it
    command cd -- "$1"
}