dwm_status

#!/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
}

# 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 hash iw
	then
		wifi=$(iw wlp2s0 link | grep SSID | sed 's,.*SSID: ,,')
		connectedto=$(iw wlp2s0 link | grep Connected | awk '{print $3}' | cut -c 10-)
	fi

	echo -e "$wifi $connectedto $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="$(grep "on-line" <(acpi -V))"
	charge="$(cat /sys/class/power_supply/BAT1/capacity)"
	if [[ ( -z $onl && ${charge} -gt 20 ) ]]; then
		echo -e "${charge}"
	elif [[ ( -z $onl && ${charge} -le 20 ) ]]; then
		echo -e "${charge}"
	else
		echo -e "${charge}"
	fi
}

print_date(){
	date "+%a %m-%d %T%:::z"
}

while true
do

	# Get new transmitted, received byte number values and current time
	get_bytes

	# Calculates speeds
	vel_recv=$(get_velocity $received_bytes $old_received_bytes $now)
	vel_trans=$(get_velocity $transmitted_bytes $old_transmitted_bytes $now)

	xsetroot -name "$(print_wifi) $(print_volume) $(print_bat) $(print_date)"

	# Update old values to perform new calculations
	old_received_bytes=$received_bytes
	old_transmitted_bytes=$transmitted_bytes
	old_time=$now

	sleep 1

done