dwm_statusBar.sh

#!/bin/bash
# Screenshot: http://s.natalian.org/2013-08-17/dwm_status.png
# Network speed stuff stolen from http://linuxclues.blogspot.sg/2009/11/shell-script-show-network-speed.html

# This function parses /proc/net/dev file searching for a line containing $interface data.
# Within that line, the first and ninth numbers after ':' are respectively the received and transmited bytes.
function get_bytes {
# Find active network interface
interface=$(ip route get 8.8.8.8 2>/dev/null| awk '{print $5}')
line=$(grep $interface /proc/net/dev | cut -d ':' -f 2 | awk '{print "received_bytes="$1, "transmitted_bytes="$9}')
eval $line
now=$(date +%s%N)
}

# Function which calculates the speed using actual and old byte number.
# Speed is shown in KByte per second when greater or equal than 1 KByte per second.
# This function should be called each second.

function get_velocity {
value=$1
old_value=$2
now=$3

timediff=$(($now - $old_time))
velKB=$(echo "1000000000*($value-$old_value)/1024/$timediff" | bc)
if test "$velKB" -gt 1024
then
	echo $(echo "scale=2; $velKB/1024" | bc)MB/s
else
	echo ${velKB}KB/s
fi
}

getMusic() {
    msc="$(ncmpcpp --current-song '{%a - %t}|{%f}')"
}


# Get initial values
get_bytes
old_received_bytes=$received_bytes
old_transmitted_bytes=$transmitted_bytes
old_time=$now

print_volume() {
	volume="$(amixer get Master | tail -n1 | sed -r 's/.*\[(.*)%\].*/\1/')"
	if test "$volume" -gt 0
	then
		echo -e "\uE05D${volume}"
	else
		echo -e "Mute"
	fi
}

print_wifi() {
	ip=$(ip route get 8.8.8.8 2>/dev/null|grep -Eo 'src [0-9.]+'|grep -Eo '[0-9.]+')

#	if=wlp3s0
#		while IFS=$': \t' read -r label value
#		do
#			case $label in SSID) SSID=$value
#				;;
#			signal) SIGNAL=$value
#				;;
#		esac
#	done < <(iw "$if" link)
#
	echo -e "$SSID$SIGNAL$ip"
}

print_mem(){
	memfree=$(($(grep -m1 'MemAvailable:' /proc/meminfo | awk '{print $2}') / 1024))
	echo -e "$memfree"
}

print_temp(){
	test -f /sys/class/thermal/thermal_zone0/temp || return 0
	echo $(head -c 2 /sys/class/thermal/thermal_zone0/temp)C
}

print_bat(){
	hash acpi || return 0
	onl="$(grep "on-line" <(acpi -V))"
	charge="$(awk '{ sum += $1 } END { print sum }' /sys/class/power_supply/BAT*/capacity)"
	if test -z "$onl"
	then
		# suspend when we close the lid
		#systemctl --user stop inhibit-lid-sleep-on-battery.service
		echo -e "${charge}"
	else
		# On mains! no need to suspend
		#systemctl --user start inhibit-lid-sleep-on-battery.service
		echo -e "${charge}"
	fi
}

print_date(){
	 #date "+%a %m-%d %T"
	 date "+%a %m-%d %I:%M:%S %p"
}

show_record(){
	test -f /tmp/r2d2 || return
	rp=$(cat /tmp/r2d2 | awk '{print $2}')
	size=$(du -h $rp | awk '{print $1}')
	echo " $size $(basename $rp)"
}

fetchmail --check 2>/dev/null | while read line; do
    new=`echo $line | sed 's/(//' | awk '{print $1-$3}'`
    if [ $new != 0 ] && [ ! -e ~/.message ]; then
        echo "New mail($new)" > ~/.message
        echo "!!! !!! !!!" >> ~/.message
        sleep 60
        if grep '^New mail' ~/.message >/dev/null 2>/dev/null; then
            rm -f ~/.message
        fi
    fi
done &
while true; do
    if [ -r ~/.message ]; then
        while read line; do
            xsetroot -name "$line"
            sleep 1
        done < ~/.message
    else
	# Get new transmitted, received byte number values and current time
	get_bytes
    getMusic
	print_volume
	#print_wifi
	# Calculates speeds
	vel_recv=$(get_velocity $received_bytes $old_received_bytes $now)
	vel_trans=$(get_velocity $transmitted_bytes $old_transmitted_bytes $now)

	xsetroot -name "$vel_recv $vel_trans $volume $msc $(print_temp) $(print_wifi) $(print_bat)% $(show_record) $(print_date)"

	# Update old values to perform new calculations
	old_received_bytes=$received_bytes
	old_transmitted_bytes=$transmitted_bytes
	old_time=$now
    fi
done &
rm -f ~/.message