Bash script for managing the mount state of external drives.

jt-dmounter

#!/bin/bash

# Helps mount/unmount disks
#
# Author: Jimmy Gleason <github.com/jimmygle
#
# The goal of this script is to provide a helper for faciliating the un/mounting 
# of drives. It's useful for mounting external drives for doing automated backups,
# or when frequently transferring data via external drives to/from a NAS.
#
# NOTE: Only tested on Debian based distros.
#
# TODO: External config file that can be managed by script (for dynamic adding of new drives)
#

# Recognizeable drives/partitions
# Get the value of each array element from `ls -la /dev/disk/by-id/` when drive is attached.
declare -A drives
drives[musty]="usb-WD..." 
drives[krusty]="usb-ST..."
drives[rusty]="usb-Seag..."
drives[speedy]="ata-San..."

# Find a drive by its key
get_drive_id_by_key() {
    if [[ -v "drives[$1]" ]]; then
        printf "${drives[$1]}"
    fi
}

# Gets mount status of drive key
mount_status() {
    local drive_id=`get_drive_id_by_key $1`
    if mount | grep "/media/$1" > /dev/null; then
        printf "mounted"
    elif ls /dev/disk/by-id/ | grep "$drive_id" > /dev/null; then
        printf "not mounted, but attached"
    else
        printf "not attached"
    fi
}

# Echoes the configured drive list
print_drive_list() {
    printf "Configured Drives/Partitions:\n"
    for key in "${!drives[@]}"; do
        local status=`mount_status $key`
        printf " - key:    $key\n"
        printf "   id:     ${drives[$key]}\n"
        printf "   status: $status\n"
    done
}


# Mounts an exfat drive/partition by its ID
mount_exfat_by_id() {
    /usr/bin/mount -t exfat /dev/disk/by-id/$1 $2
}

# Umounts an exfat drive/partition by its ID
unmount_exfat_by_id() {
    /usr/bin/umount /dev/disk/by-id/$1
}

# Runs mounting operations
mount_runner() {
    local drive_id=`get_drive_id_by_key $1`
    local mount_path="/media/$1"
    local mount_state=`mount_status $1`

    if [ -z "$drive_id" ]; then
        printf "\nERROR: Drive with key '$1' not found.\n\n"
        print_drive_list
        exit 1 
    fi

    case "$mount_state" in
        "mounted")
            printf "Drive '$1' is already mounted (probably at $mount_path)\n"
        ;;
        "not attached")
            printf "Drive '$1' is not plugged in (ID $drive_id)\n"
        ;;
        "not mounted, but attached")
            printf "Attempting to mount $1 to $mount_path\n"
            mkdir -p $mount_path
            mount_exfat_by_id $drive_id $mount_path
        ;;
        *)
            printf "\nERROR: Unable to determine status for '$1' (ID $drive_id)\n\n"
            exit 1
        ;;
    esac
}

# Runs unmounting operations
unmount_runner() {
    local drive_id=`get_drive_id_by_key $1`
    local mount_path="/media/$1"
    local mount_state=`mount_status $1`

    if [ -z "$drive_id" ]; then
        printf "\nERROR: Drive with key '$1' not found\n\n"
        print_drive_list
        exit 1
    fi

    case "$mount_state" in
        "mounted")
            printf "Attempting to unmount $mount_path\n"
            unmount_exfat_by_id $drive_id
        ;;
        "not attached")
            printf "Drive '$1' is not plugged in (ID '$drive_id')\n"
        ;;
        "not mounted, but attached")
            printf "Drive '$1' is not mounted\n"
        ;;
        *)
            printf "\nERROR: Unable to determine status for '$1' (ID $drive_id)\n\n"
            exit 1
        ;;
    esac
}


# Runner - Handles drive selection/input
case "$1" in
    # Mount
    "m")
        mount_runner $2
    ;;
    # Mount all
    "ma")
        printf "Attempting to mount all drives\n"
        for key in "${!drives[@]}"; do
            mount_runner $key
        done
    ;;
    # Unmount
    "u")
        unmount_runner $2
    ;;
    # Unmount all
    "ua")
        printf "Attempting to unmount all drives\n"
        for key in "${!drives[@]}"; do
            unmount_runner $key
        done
    ;;
    *)
        printf "\njimmys's drive mounting helper\n"
        printf "\nPurpose: Help faciliate the quick mounting/unmounting of commonly used media drives.\n\n"
        printf "Usage:\n"
        printf " jt-mounter m <drive_key>      Mounts drive of given key\n"
        printf " jt-mounter ma                 Mounts all unmounted and plugged in drives\n"
        printf " jt-mounter u <drive_key>      Unmounts drive of given key\n"
        printf " jt-mounter ua                 Unmounts all drives that are currently mounted\n\n"
        printf "Example:\n"
        printf " jt-mounter m krusty           Mounts drive /dev/disk/by-id/usb-ST1000... to /media/krusty\n\n"
        print_drive_list
        printf "\n"
        exit 1
    ;;
esac