Check outgoing port

netstatcheck.sh

#!/bin/bash

is_someprocess_connected() {
    # Run netstat command and store the output
    is_someprocess_connected_somewhere=0
    output=$(stdbuf -oL netstat -nputw 2>/dev/null)
    port=$1

    # Process the output line by line
    while IFS= read -r line; do
        # Check if the line contains an active connection
        if [[ $line =~ (tcp|udp)[[:space:]] ]]; then
            # Extract the process name, PID, and port from the line
            process_name=$(echo "$line" | awk '{print $7}')
            dest=$(echo "$line" | awk '{print $5}')
            ip_dest=$(echo "$dest" | awk -F':' '{print $1}')
            port_dest=$(echo "$dest" | awk -F':' '{print $NF}')

            # Print the process name, PID, and port
            if [ "$port_dest" -eq "$port" ]; then
                echo "Process $process_name is connected to IP $ip_dest port $port!"
                is_someprocess_connected_somewhere=1
            fi
        fi
    done <<<"$output"

    return $is_someprocess_connected_somewhere
}

is_someprocess_connected "443"
if (($? == 1)); then
    exit 3
else
    echo "OK"
    exit 0
fi