Reading Command-Line Arguments in PHP

CLI arguments come from $argv and optional flags can be parsed with getopt().

What It Does

CLI arguments come from $argv and optional flags can be parsed with getopt(). 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

The raw $argv array includes the script name as its first element.

<?php
$argv = ['app.php', 'import', 'list.csv'];
if (count($argv) !== 3) throw new InvalidArgumentException('Usage: app.php import file');
echo $argv[1] . ':' . $argv[2];

Important Behavior and Edge Cases

Always handle missing values, quoting and error exit codes.

Comparison with Related Functions or Approaches

Common Beginner Mistakes

Key Takeaways

• CLI arguments come from $argv and optional flags can be parsed with getopt().
• Always handle missing values, quoting and error exit codes.
• Environment variables are better for configuration that should not appear in shell histories.

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