Shell script to print HDD temperatures (no root required!)

hdd-temps.sh

#!/bin/sh             

# Dependencies: 
# 1. qdbus 
#    sudo apt install qdbus
# 2. udisks2
#    sudo apt install udisks2 && sudo systemctl start udisks2
#
# This could probably be rewritten to use dbus-send instead of qdbus.
                                                                                                                                                                                                   
TEMP_LOW_MAX="35"                                                                                                                                                                                  
TEMP_MED_MAX="55"                                                                                                                                                                                                              
                                                                                                                                                                                                                               
COLOR_LOW="42"          # Green                                                                                                                                                                                                
COLOR_MED="43"          # Yellow                                                                                                                                                                                               
COLOR_HIGH="41"         # Red                                                                                                                                                                                                  
                                                                                                                                                                                                                               
print_help() {                                                                                                                                                                                                                 
        echo "hdd_temps - print temperatures for all available hard drives"
        echo "Usage: hdd_temps [options]"
        echo "Options:"
        echo "  -c | --colorize         colorize temperatures"
        echo "  -h | --help             print this page"
}

dbus_call(){
        local type bus object method
        type=$1
        bus=$2
        object=$3
        method=$4

        qdbus --$type $bus $object $method 2>/dev/null
}

round() {
        printf "%.0f" "$1"
}

get_color() {
        local celcius rounded color

        celcius=$1
        rounded=$(round $celcius)

        if [ $rounded -lt $TEMP_LOW_MAX ]; then
                color=$COLOR_LOW
        elif [ $rounded -lt $TEMP_MED_MAX ]; then
                color=$COLOR_MED
        else
                color=$COLOR_HIGH
        fi

        echo $color
}

print_temps() {
        local colorize type bus vendor model kelvins celcius temp_str
        colorize=$1
        type="system"
        bus="org.freedesktop.UDisks2"

        colorize=$1

        dbus_call $type $bus | grep drives\/ | while read -r object; do
                vendor=$(dbus_call $type $bus $object $bus.Drive.Vendor)
                model=$(dbus_call $type $bus $object $bus.Drive.Model)
                kelvins=$(dbus_call $type $bus $object $bus.Drive.Ata.SmartTemperature)

                if [ $? -eq 0 ]; then
                        celcius=$(echo $kelvins - 273 | bc)
                        if [ -z "$colorize" ]; then
                                color="0"
                        else
                                color=$(get_color $celcius)
                        fi

                        printf "%-25s" "$model:"
                        echo -n "\e[${color}m${celcius}\e[0m\n"
                fi
        done
}

main() {
        local colorize

        while [ $# -gt 0 ]; do
                case $1 in
                        -c|--colorize)
                                colorize=$1
                                shift
                                ;;
                        -h|--help)
                                print_help
                                return 0
                                ;;
                        *) 
                                echo "Unknown uption - $(echo $1 | sed 's/-//g')" 1>&2
                                print_help
                                return 1
                                ;;
                esac
        done

        print_temps $colorize
}

main $@