Safely eject removable devices from command line (linux)

ejectUSB.sh

#!/bin/bash
# Equivalent to safely removing devices

# The parameter is (part of) the mountpoint
mountpoint=$1
if [[ -z "$mountpoint" ]] || [[ "$mountpoint" == "--help" ]] ; then
    echo "Usage: ${0##*/} mountpoint"
    exit 1
fi

# Remove trailing slash
if [[ "${mountpoint: -1}" == "/" ]]; then
    mountpoint=${mountpoint:0:-1}
fi

# Check mountpoint by filesystem
if [[ ! -d "$mountpoint" ]] && [[ ! -d "/media/${mountpoint}" ]] && [[ ! -d "/mnt/${mountpoint}" ]]; then
    echo "Mountpoint not found."
    exit 2
fi

# Get partition name from mountpoint
partionname=$(mount | grep "${mountpoint}" | cut -d ' ' -f 1)
if [[ -z "$partionname" ]] ||  [[ "${#partionname}" -lt "8" ]]; then
    echo "Mountpoint not found."
    exit 3
fi

# Get device name and all associated partitions
if [[ $partionname = *[[:digit:]] ]]; then
    devicename=${partionname:0:-1}
    partitionlist=$(ls -1 $devicename*)
    numpartions=$(echo $partitionlist | grep -o ' ' | wc -l)

    # Iterate over all partitions of the device
    for ((i=1; i<=$numpartions; i++)); do
        udisksctl unmount -b ${devicename}${i}
        if [[ "$?" -ne 0 ]]; then
            flist=$(lsof | head -n1 && lsof | grep ${mountpoint} --color=NEVER)
            fnr=$(echo -e "${flist}" | wc -l)
            if [[ "$fnr" -gt 1 ]]; then
                echo -e "${flist}"
            fi
            exit 4
        fi
    done
else
    devicename=$partionname
    udisksctl unmount -b ${devicename}
    if [[ "$?" -ne 0 ]]; then
        flist=$(lsof | head -n1 && lsof | grep ${mountpoint} --color=NEVER)
        fnr=$(echo -e "${flist}" | wc -l)
        if [[ "$fnr" -gt 1 ]]; then
            echo -e "${flist}"
        fi
        exit 4
    fi
fi

# Lastly power off the device
udisksctl power-off -b ${devicename}
if [[ "$?" -eq 0 ]]; then
    # For safety wait 500 ms
    sleep 0.5
    echo "${devicename} may now be unplugged."
else
    exit 5
fi