Signal processing in three scripting languages:

PHP

<?php

function handleSignal($signal) {
    echo "Received {$signal}..." . PHP_EOL;

    switch ($signal) {
        case SIGTERM:
            // maybe close stuff, etc
            exit 0;
        case SIGINT:
            // maybe close stuff, etc
            exit 0;
    }
}

pcntl_signal(SIGTERM, "handleSignal");
pcntl_signal(SIGINT, "handleSignal");

while (true) {
    pcntl_signal_dispatch();
    echo "Running..." . PHP_EOL;
    sleep(10);
}

Run:

> php signal.php
# in another terminal window
> kill -TERM $(ps ax|grep "php signal.php"|grep -v "php"|awk '{print $1}')

Javascript

console.log('  Request started: ' + (new Date));

handleSignal = signal => {
  let dt = (new Date)
  console.log(`  Received ${signal} at ${dt}, shutting down gracefully...`);
}

process.on('SIGTERM', signal => {
  handleSignal(signal)
});

process.on('SIGQUIT', signal => {
  handleSignal(signal)
});

process.on('SIGINT', signal => {
  handleSignal(signal)
});

console.log('  Request started: ' + (new Date));

console.log('  firing off req 1')
fetch('https://<website>/sleep.php?t=10')
.then(response => {
    if (!response.ok) {
    throw new Error(`HTTP error! status: ${response.status}`);
    }
    return response.json();
})
.then(data => {
    console.log('  Data fetched successfully:', data);
    console.log('    At: ' + (new Date));
})
.catch(error => {
    console.error('  Error fetching data:', error);
    console.log('    At: ' + (new Date));
});

Run:

> node signal.js
# in another terminal window
> kill -TERM $(ps ax|grep "node signal.js"|grep -v "node"|awk '{print $1}')

Bash

#!/bin/bash

handleSignal() {
    echo "Received signal."
    exit 0
}

trap handleSignal SIGTERM
trap handleSignal SIGINT

while true; do
    echo "Running..."
    sleep 10
done

Run:

> bash signal.sh
# in another terminal window
> kill -TERM $(ps ax|grep "bash signal.sh"|grep -v "bash"|awk '{print $1}')