PHP CLI Command-Line Argument Parsing

CLI argument parsing reads options from the command invocation rather than HTTP requests.

What It Does

CLI argument parsing reads options from the command invocation rather than HTTP requests. The following examples distinguish a normal use case, a boundary case and a practical application.

Requirements and Compatibility

PHP 8.x and a local test environment. Apply input validation, correct error handling and the requirements of any optional libraries.

The code focuses on the core concept. Production implementation may also need routes, validation, persistence, authorization or deployment tooling.

Example 1: Basic Behavior

Understand the primary operation and its inputs.

<?php
$argv = ['tool.php', '--task=export'];
$task = str_starts_with($argv[1], '--task=') ? substr($argv[1], 7) : '';
echo $argv[1]; // For actual parsing, call getopt() on the live CLI process

Example 2: Another Case

Check failure behavior or a different execution path.

<?php
$args = ['script.php', '--count', '5'];
$index = array_search('--count', $args, true);
$count = $index !== false ? filter_var($args[$index + 1] ?? null, FILTER_VALIDATE_INT) : false;
echo $count === false ? 'Invalid count' : $count;

Practical Example: Putting It to Use

Parse option names and values, then validate required arguments.

<?php
$arguments = ['tool.php', '--limit=25', '--dry-run'];
$options = []; foreach (array_slice($arguments, 1) as $arg) { if (preg_match('/^--([a-z-]+)(?:=(.*))?$/D', $arg, $m)) $options[$m[1]] = $m[2] ?? true; }
print_r($options);

Important Behavior and Edge Cases

Validate both missing and extra arguments and avoid assuming shell quoting is uniform.

Comparison with Related Functions or Approaches

Common Beginner Mistakes

Key Takeaways

• CLI argument parsing reads options from the command invocation rather than HTTP requests.
• Validate both missing and extra arguments and avoid assuming shell quoting is uniform.
• $argv offers raw arguments; getopt() handles common option conventions.

Before adapting these examples, verify the return values, test the failure paths and confirm that your application meets its security and environment requirements.