os

Operating system interface.

Table of contents

1. Overview
2. os.clock()
3. os.time()
4. os.exit(code)
5. Example Usage
6. Notes

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Overview

The os module provides access to operating system functions. It must be explicitly imported:

const os = import("os");
let t = os.time();

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os.clock()

Returns CPU time used by the program in seconds.

let start = os.clock();

// ... do some work ...
for (let i = 0; i < 1000000; i++) {
    let x = i * 2;
}

let elapsed = os.clock() - start;
print("Elapsed: " + tostring(elapsed) + " seconds");

Returns: CPU time as a floating-point number

Use Case: Measuring performance and execution time

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os.time()

Returns current time as a Unix timestamp (seconds since epoch).

let timestamp = os.time();
print(timestamp);  // e.g., 1672531200

// Calculate time difference
let start = os.time();
// ... wait or do work ...
let elapsed = os.time() - start;
print("Real time elapsed: " + tostring(elapsed) + " seconds");

Returns: Integer timestamp

Use Case: Getting current time, calculating real-time durations

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os.exit(code)

Exits the program with the given status code.

// Success
os.exit(0);

// Error
os.exit(1);

// Custom error code
os.exit(42);

Parameters:

• code - Exit status code (0 = success, non-zero = error)

Note: This function does not return - the program terminates immediately

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Example Usage

const os = import("os");

// Benchmark a function
function benchmark(func) {
    let start = os.clock();
    func();
    let elapsed = os.clock() - start;
    return elapsed;
}

function slowOperation() {
    let sum = 0;
    for (let i = 0; i < 1000000; i++) {
        sum = sum + i;
    }
    return sum;
}

let time = benchmark(slowOperation);
print("Operation took: " + tostring(time) + " seconds");

// Log with timestamp
let timestamp = os.time();
print("[" + tostring(timestamp) + "] Application started");

// Conditional exit
function validateConfig(config) {
    if (config == nil) {
        print("Error: Config file not found");
        os.exit(1);
    }
}

let config = loadConfig();
validateConfig(config);
// ... continue if validation passed

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Notes

• os.clock() measures CPU time (time spent executing)
• os.time() measures real wall-clock time
• For accurate benchmarking, use os.clock()
• For timestamps and real-time measurements, use os.time()