Processes - Knowledge of Laravel

Introduction

Laravel’s Process facade is a thin wrapper around the Symfony Process component. It provides a clean, expressive API for invoking external processes from your application.

Invoking processes

Use Process::run() to execute a command synchronously and wait for it to finish.

use Illuminate\Support\Facades\Process;

$result = Process::run('ls -la');

return $result->output();

The returned ProcessResult instance exposes several inspection methods:

$result = Process::run('ls -la');

$result->command();       // The command that was run
$result->successful();    // true if exit code is 0
$result->failed();        // true if exit code is non-zero
$result->output();        // Standard output (stdout)
$result->errorOutput();   // Standard error output (stderr)
$result->exitCode();      // The exit code

Throwing on failure

To throw an Illuminate\Process\Exceptions\ProcessFailedException when a process fails, use throw() or throwIf(). If the process succeeded, the ProcessResult instance is returned.

$result = Process::run('ls -la')->throw();

$result = Process::run('ls -la')->throwIf($condition);

Process options

Working directory

Use path() to set the working directory. If omitted, the process inherits the directory of the currently executing PHP script.

$result = Process::path(__DIR__)->run('ls -la');

Standard input

Pass data to the process via standard input using input().

$result = Process::input('Hello World')->run('cat');

Timeouts

Processes time out after 60 seconds by default, throwing a ProcessTimedOutException. Override with timeout().

$result = Process::timeout(120)->run('bash import.sh');

You can also pass a CarbonInterval helper function:

use function Illuminate\Support\minutes;

$result = Process::timeout(minutes(2))->run('bash import.sh');

To disable the timeout entirely, use forever().

$result = Process::forever()->run('bash import.sh');

Set an idle timeout (maximum seconds with no output) with idleTimeout().

$result = Process::timeout(60)->idleTimeout(30)->run('bash import.sh');

Environment variables

Provide environment variables with env(). The process also inherits all system environment variables.

$result = Process::forever()
    ->env(['IMPORT_PATH' => __DIR__])
    ->run('bash import.sh');

Pass false to remove an inherited variable.

$result = Process::forever()
    ->env(['LOAD_PATH' => false])
    ->run('bash import.sh');

Disabling output

When you don’t need the output, call quietly() to conserve memory.

$result = Process::quietly()->run('bash import.sh');

Real-time output

Pass a closure as the second argument to run() to receive output as it is produced.

$result = Process::run('ls -la', function (string $type, string $output) {
    echo $output;
});

Pipelines

Process::pipe() lets you chain commands so that the output of one becomes the input of the next. The result of the last command in the pipeline is returned.

use Illuminate\Process\Pipe;
use Illuminate\Support\Facades\Process;

$result = Process::pipe(function (Pipe $pipe) {
    $pipe->command('cat example.txt');
    $pipe->command('grep -i "laravel"');
});

if ($result->successful()) {
    // ...
}

You can also pass an array of command strings.

$result = Process::pipe([
    'cat example.txt',
    'grep -i "laravel"',
]);

Assign string keys with as() to identify each process’s output in the closure.

$result = Process::pipe(function (Pipe $pipe) {
    $pipe->as('first')->command('cat example.txt');
    $pipe->as('second')->command('grep -i "laravel"');
}, function (string $type, string $output, string $key) {
    // $key is 'first' or 'second'
});

Asynchronous processes

Process::start() launches a process without waiting for it to finish, allowing your application to do other work in the meantime.

$process = Process::timeout(120)->start('bash import.sh');

while ($process->running()) {
    // do other work
}

$result = $process->wait();

Process IDs and signals

Retrieve the OS-assigned process ID with id().

$process = Process::start('bash import.sh');

return $process->id();

Send a signal to the running process with signal().

$process->signal(SIGUSR2);

Asynchronous output

While the process is running, use latestOutput() and latestErrorOutput() to read new output since the last check.

$process = Process::timeout(120)->start('bash import.sh');

while ($process->running()) {
    echo $process->latestOutput();
    echo $process->latestErrorOutput();

    sleep(1);
}

Wait until a specific string appears in the output using waitUntil().

$process = Process::start('bash import.sh');

$process->waitUntil(function (string $type, string $output) {
    return $output === 'Ready...';
});

Checking for timeouts

Call ensureNotTimedOut() inside a loop to throw a timeout exception if the process has exceeded its timeout.

$process = Process::timeout(120)->start('bash import.sh');

while ($process->running()) {
    $process->ensureNotTimedOut();

    sleep(1);
}

Concurrent processes

Process::pool() runs multiple processes in parallel.

use Illuminate\Process\Pool;
use Illuminate\Support\Facades\Process;

$pool = Process::pool(function (Pool $pool) {
    $pool->path(__DIR__)->command('bash import-1.sh');
    $pool->path(__DIR__)->command('bash import-2.sh');
    $pool->path(__DIR__)->command('bash import-3.sh');
})->start(function (string $type, string $output, int $key) {
    // ...
});

while ($pool->running()->isNotEmpty()) {
    // ...
}

$results = $pool->wait();

Process::concurrently() is a shorthand that starts the pool and immediately waits for all results.

[$first, $second, $third] = Process::concurrently(function (Pool $pool) {
    $pool->path(__DIR__)->command('ls -la');
    $pool->path(app_path())->command('ls -la');
    $pool->path(storage_path())->command('ls -la');
});

echo $first->output();

Naming pool processes

Use as() to assign string keys and access results by name.

$pool = Process::pool(function (Pool $pool) {
    $pool->as('first')->command('bash import-1.sh');
    $pool->as('second')->command('bash import-2.sh');
    $pool->as('third')->command('bash import-3.sh');
})->start(function (string $type, string $output, string $key) {
    // ...
});

$results = $pool->wait();

return $results['first']->output();

Send a signal to every process in the pool at once.

$pool->signal(SIGUSR2);

Testing

Faking processes

Call Process::fake() to prevent any real processes from running during tests.

use Illuminate\Support\Facades\Process;

Process::fake();

$response = $this->get('/import');

Process::assertRan('bash import.sh');

Specify output and exit codes for faked processes.

Process::fake([
    '*' => Process::result(
        output: 'Test output',
        errorOutput: 'Test error output',
        exitCode: 1,
    ),
]);

Faking specific processes

Use command patterns as keys to fake individual commands differently.

Process::fake([
    'cat *'  => Process::result(output: 'file contents'),
    'ls -la' => Process::result(output: 'file listing'),
]);

Faking sequences

Return different results for repeated calls to the same command.

Process::fake([
    'ls *' => [
        Process::result('first time'),
        Process::result('second time'),
    ],
]);

Assertions

Method	Description
`Process::assertRan('command')`	Assert the command was run
`Process::assertNotRan('command')`	Assert the command was not run
`Process::assertRan(fn)`	Assert using a closure for detailed inspection
`Process::assertRanTimes('command', 3)`	Assert the command ran a specific number of times

Preventing stray processes

Call Process::preventStrayProcesses() to throw an exception when a process runs without a matching fake.

Process::preventStrayProcesses();

Process::fake([
    'ls *' => Process::result('file listing'),
]);

// Exception: no fake defined for 'bash import.sh'
Process::run('bash import.sh');

Artisan console

Create custom commands that invoke processes

Queues

Compare with queue-based async processing

Documentation Index

​Introduction

​Invoking processes

​Throwing on failure

​Process options

​Working directory

​Standard input

​Timeouts

​Environment variables

​Disabling output

​Real-time output

​Pipelines

​Asynchronous processes

​Process IDs and signals

​Asynchronous output

​Checking for timeouts

​Concurrent processes

​Naming pool processes

​Testing

​Faking processes

​Faking specific processes

​Faking sequences

​Assertions

​Preventing stray processes

​Related pages