A bash script to add RAM usage percent as a new item in the XFCE panel

calculate_ram_usage.sh

#!/bin/bash
# Prerequisities
# 0) XFCE
# 1) Save this script in your home directory as: /home/your_user_name/calculate_ram_usage.sh
# 2) Add a new XFCE Generic Monitor Applet item (with the settings: no label, 1 second refresh period): /home/your_user_name/calculate_ram_usage.sh

output=$(free)

# Use grep with perl-regex (-P) to extract numbers and store them in an array
numbers=($(echo "$output" | grep -oP '\d+'))

# Extract the first and the sixth numbers
total=${numbers[0]}
available=${numbers[5]}

# Divide the numbers
result=$(echo "scale=0; 100*($total - $available)/$total" | bc)

echo "$result%"