Command-Line PHP

<?php

declare(strict_types=1);

var_dump(PHP_SAPI);                              // string(3) "cli"
var_dump(ini_get('max_execution_time'));         // string(1) "0"
var_dump(ini_get('html_errors'), ini_get('implicit_flush'));   // "0" "1"
var_dump(getcwd() !== false, __DIR__ !== '');    // the cwd and the script directory can differ

<?php

declare(strict_types=1);

// export-loans.php
$options = getopt('vf:', ['format:', 'dry-run', 'limit::'], $restIndex);
$files = array_slice($argv, $restIndex);

$verbose = array_key_exists('v', $options);                 // flags are present with value false
$format = $options['f'] ?? $options['format'] ?? 'table';
$limit = isset($options['limit']) ? (int) $options['limit'] : null;

printf("verbose=%s format=%s dry-run=%s limit=%s files=%s\n",
    var_export($verbose, true), $format, var_export(isset($options['dry-run']), true), $limit ?? 'none', implode(',', $files));

$ php export-loans.php -v -f csv --dry-run --limit=50 loans-october.csv
verbose=true format=csv dry-run=true limit=50 files=loans-october.csv

$ php -r 'exit(3);'; echo "code=$?"
code=3
$ php -r 'exit("failed\n");'; echo "code=$?"
failed
code=0
$ php -r 'throw new Exception("x");' 2>/dev/null; echo "code=$?"
code=255

<?php

declare(strict_types=1);

function main(array $argv): int
{
    if (count($argv) < 2) {
        fwrite(STDERR, "usage: {$argv[0]} <isbn>\n");
        return 64;                                     // EX_USAGE, following the BSD sysexits convention
    }
    fwrite(STDOUT, "Looking up {$argv[1]}\n");
    return 0;
}

$code = main(['lookup.php']);
echo "would exit with {$code}\n";                      // in a real script: exit(main($argv));

<?php

declare(strict_types=1);

// Safe: no shell is involved; each array element is one argument
$process = proc_open(['sort', '-r'], [0 => ['pipe', 'r'], 1 => ['pipe', 'w'], 2 => ['pipe', 'w']], $pipes);
fwrite($pipes[0], "Kindred\nSolaris\nDawn\n");
fclose($pipes[0]);
echo stream_get_contents($pipes[1]);                  // Solaris, Kindred, Dawn (reverse order)
fclose($pipes[1]);
fclose($pipes[2]);
echo 'exit code: ', proc_close($process), "\n";       // exit code: 0

// When a shell is unavoidable: escape each argument
$userFile = "notes; rm -rf /";
var_dump(escapeshellarg($userFile));                  // string(17) "'notes; rm -rf /'"
exec('ls -l ' . escapeshellarg('/etc/hostname') . ' 2>&1', $output, $code);
echo $code === 0 ? "listed\n" : "failed\n";

$ phpdbg -qrr script.php           # run a script under phpdbg, quiet, then quit
$ phpdbg script.php
prompt> break script.php:12
prompt> run
prompt> ev $loan->dueAt()          # evaluate an expression at the breakpoint
prompt> next

composer require symfony/console

#!/usr/bin/env php
<?php

declare(strict_types=1);

// bin/console.php
require __DIR__ . '/../vendor/autoload.php';

use Symfony\Component\Console\Application;
use Symfony\Component\Console\Attribute\Argument;
use Symfony\Component\Console\Attribute\AsCommand;
use Symfony\Component\Console\Attribute\Option;
use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Style\SymfonyStyle;

#[AsCommand(name: 'catalogue:overdue', description: 'List overdue loans')]
final class OverdueCommand
{
    public function __invoke(
        SymfonyStyle $io,
        #[Argument('Days late threshold')] int $days = 0,
        #[Option('Output format: table or csv')] string $format = 'table',
    ): int {
        $rows = [['978-0-00-000001-1', 'Kindred', 13], ['978-0-00-000002-8', 'Dawn', 2]];
        $rows = array_values(array_filter($rows, fn (array $r): bool => $r[2] > $days));

        if ($format === 'csv') {
            foreach ($rows as $row) {
                $io->writeln(implode(',', $row));
            }
        } else {
            $io->table(['ISBN', 'Title', 'Days late'], $rows);
        }
        $io->success(count($rows) . ' overdue loan(s)');
        return Command::SUCCESS;
    }
}

$app = new Application('Library catalogue', '1.0');
$app->addCommand(new OverdueCommand());
$app->run();

$ php bin/console.php catalogue:overdue 5
 ------------------- --------- -----------
  ISBN                Title     Days late
 ------------------- --------- -----------
  978-0-00-000001-1   Kindred   13
 ------------------- --------- -----------

 [OK] 1 overdue loan(s)