process_management.smash

// SmashLang Process Management Example

// Import the process management module
import "std_process.smash";

// Basic process information
fn processInfoDemo() {
    print("Process Information Demo");
    print("------------------------");
    
    // Get current process ID
    const pid = process.pid();
    print("Current process ID: " + pid);
    
    // Get parent process ID
    const ppid = process.ppid();
    print("Parent process ID: " + ppid);
    
    // Get current working directory
    const cwd = process.cwd();
    print("Current working directory: " + cwd);
    
    // Get environment variables
    print("\nEnvironment Variables:");
    const env = process.env();
    const keys = Object.keys(env).sort();
    for (let i = 0; i < Math.min(5, keys.length); i++) {
        const key = keys[i];
        print(`${key}=${env[key]}`);
    }
    print(`... and ${keys.length - 5} more`);
    
    // Get specific environment variable
    const path = process.getenv("PATH");
    print("\nPATH environment variable:");
    print(path);
}

// Execute external commands
fn executeCommandDemo() {
    print("\nExecute Command Demo");
    print("-------------------");
    
    // Simple command execution
    print("Running 'echo Hello, SmashLang!'");
    const result = process.exec("echo Hello, SmashLang!");
    print("Exit code: " + result.exitCode);
    print("Output: " + result.stdout.trim());
    
    // Command with arguments
    print("\nListing files in current directory");
    const lsResult = process.exec("ls -la");
    print("Exit code: " + lsResult.exitCode);
    
    // Show first few lines of output
    const lines = lsResult.stdout.split("\n");
    for (let i = 0; i < Math.min(5, lines.length); i++) {
        print(lines[i]);
    }
    if (lines.length > 5) {
        print(`... and ${lines.length - 5} more lines`);
    }
    
    // Handle command errors
    print("\nRunning non-existent command");
    const errorResult = process.exec("nonexistentcommand");
    print("Exit code: " + errorResult.exitCode);
    print("Error: " + errorResult.stderr.trim());
}

// Spawn processes
fn spawnProcessDemo() {
    print("\nSpawn Process Demo");
    print("-----------------");
    
    // Spawn a long-running process
    print("Spawning a process that counts to 5");
    
    const child = process.spawn("bash", ["-c", "for i in {1..5}; do echo Count: $i; sleep 1; done"]);
    
    print("Child process spawned with PID: " + child.pid);
    
    // Set up event handlers
    child.onStdout((data) => {
        print("STDOUT: " + data.trim());
    });
    
    child.onStderr((data) => {
        print("STDERR: " + data.trim());
    });
    
    child.onExit((code) => {
        print("Child process exited with code: " + code);
    });
    
    // Wait for the child process to complete
    print("Waiting for child process to complete...");
    child.wait();
    print("Child process completed");
}

// Process signals
fn signalHandlingDemo() {
    print("\nSignal Handling Demo");
    print("-------------------");
    
    // Register signal handlers
    process.onSignal("SIGINT", () => {
        print("Received SIGINT signal (Ctrl+C)");
        print("Cleaning up resources...");
        print("Exiting gracefully");
        process.exit(0);
    });
    
    process.onSignal("SIGTERM", () => {
        print("Received SIGTERM signal");
        print("Exiting gracefully");
        process.exit(0);
    });
    
    // Spawn a child process and send it a signal
    print("Spawning a child process that sleeps for 10 seconds");
    const child = process.spawn("sleep", ["10"]);
    print("Child process spawned with PID: " + child.pid);
    
    // Wait a moment and then send a signal to the child
    print("Sending SIGTERM to child process in 2 seconds...");
    process.setTimeout(() => {
        print("Sending SIGTERM to child process");
        process.kill(child.pid, "SIGTERM");
    }, 2000);
    
    // Wait for the child to exit
    const exitCode = child.wait();
    print("Child process exited with code: " + exitCode);
}

// Run the demos
processInfoDemo();
executeCommandDemo();
spawnProcessDemo();
signalHandlingDemo();