"select" to switch net interface and "monitor" to watch your net speed

smart-polybar-net-speed.sh

#!/bin/bash

# Temporary file to store the selected interface
INTERFACE_FILE="/tmp/selected_network_interface"

# Function to get available network interfaces
get_interfaces() {
    ls /sys/class/net | grep -v lo
}

# Function to check internet connectivity
check_internet() {
    ping -c 1 google.com > /dev/null 2>&1
    return $?
}

# Function to safely get network statistics
get_stat() {
    local stat_file=$1
    if [ -f "$stat_file" ]; then
        cat "$stat_file"
    else
        echo 0
    fi
}

# Function to monitor network speed
monitor_speed() {
    INTERFACE=$1

    # Get initial download and upload bytes
    RX1=$(get_stat "/sys/class/net/$INTERFACE/statistics/rx_bytes")
    TX1=$(get_stat "/sys/class/net/$INTERFACE/statistics/tx_bytes")

    # Wait for one second
    sleep 1

    # Get new download and upload bytes
    RX2=$(get_stat "/sys/class/net/$INTERFACE/statistics/rx_bytes")
    TX2=$(get_stat "/sys/class/net/$INTERFACE/statistics/tx_bytes")

    # Calculate bytes transferred in the interval
    RXBPS=$(($RX2 - $RX1))
    TXBPS=$(($TX2 - $TX1))

    # Convert bytes per second to kilobytes per second
    RXKBPS=$(echo "scale=2; $RXBPS/1024" | bc)
    TXKBPS=$(echo "scale=2; $TXBPS/1024" | bc)

    # Output the speeds
    echo " $RXKBPS kB/s  $TXKBPS kB/s"
}

# Function to select network interface
select_interface() {
    INTERFACE=$(get_interfaces | rofi -dmenu -p "Select Network Interface:")
    if [ -z "$INTERFACE" ]; then
        echo "No interface selected"
        exit 1
    fi
    echo $INTERFACE > $INTERFACE_FILE
}

# Function to read interface from the temporary file
read_interface() {
    INTERFACE=$(cat $INTERFACE_FILE)
    if [ -z "$INTERFACE" ]; then
        echo "No interface selected"
        exit 1
    fi
}

# Main script
if [ "$1" == "monitor" ]; then
    if [ ! -f "$INTERFACE_FILE" ]; then
        echo "No network interface selected. Please run './script.sh select' first."
        exit 1
    fi
    read_interface
    monitor_speed $INTERFACE
elif [ "$1" == "select" ]; then
    select_interface
else
    echo "Usage: $0 [monitor|select]"
    exit 1
fi

# [module/net-speed]
# type = custom/script
# exec = ~/.config/polybar/_shared_scripts/net-speed.sh monitor
# click-left = ~/.config/polybar/_shared_scripts/net-speed.sh select
# interval = 2
# label = "%output%"