Chronometer

#!/bin/bash
# USE: ./stopwatch.scr and select an option.
    echo
    TZ=GMT date +"%d:%m:%Y - %H:%M:%S:$(date +%3N) - %s"
    echo
# Menu Function
show_menu() {
    echo "Select an option:"
    echo "1) Start Chrono for 'Human Biology works and execises (Published on diaspora.psyco.fr/tags/human_biology')"
    echo "2) View License"
    echo "3) Exit"
}

# License Function
show_license() {
    echo -e "\n19:02:2025 (1739962099) Copyright (c) Peregrino Alemán Armas"
    echo "Permission is hereby granted, free of charge, to any person obtaining"
    echo "a copy of this software and associated documentation files (the"
    echo "\"Software\"), to deal in the Software without restriction, including"
    echo "without limitation the rights to use, copy, modify, merge, publish,"
    echo "distribute, sublicense, and/or sell copies of the Software, and to"
    echo "permit persons to whom the Software is furnished to do so, subject to"
    echo "the following conditions:"
    echo
    echo "The above copyright notice and this permission notice shall be"
    echo "included in all copies or substantial portions of the Software."
    echo
    echo "THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND,"
    echo "EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF"
    echo "MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND"
    echo "NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE"
    echo "LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION"
    echo "OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION"
    echo "WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE."
    echo -e "\n"
}

# Stopwatch Function
start_stopwatch() {
    echo "Chrono 'Race' started. Press '1' to stop."

    start_time=$(date +%s%3N)  # Start time in milliseconds

    while true; do
        current_time=$(date +%s%3N)  # Get current time in milliseconds
        elapsed=$((current_time - start_time))  # Calculate elapsed time

        min=$((elapsed / 60000))  # Convert to minutes
        sec=$(( (elapsed / 1000) % 60 ))  # Convert to seconds
        ms=$((elapsed % 1000))  # Get milliseconds

        printf "\r%02d:%02d:%03d" "$min" "$sec" "$ms"  # Print formatted time

        # Check for keypress to stop stopwatch
        read -t 0.01 -n 1 key
        if [[ "$key" == "1" ]]; then
            echo -e "\nStopped at: $min:$sec:$ms"
            return
        fi
    done
}

# Main Menu Loop
while true; do
    show_menu
    echo ''
    read -p "             Enter choice: " choice

    case $choice in
        1) start_stopwatch ;;
        2) show_license ;;
        3) echo -e "\nGoodbye!"; exit 0 ;;
        *) echo "Invalid option. Try again." ;;
    esac

done