PHP Filesystem Reference

How it works

Filesystem helpers have return-value, caching and race boundaries. Checking existence and opening later are separate operations, so a prior check cannot eliminate every concurrent change. Keep trusted roots, use appropriate open modes and handle failures at the operation itself. Directory enumeration also needs symlink and permission policies. The related inventory includes legacy spellings and aliases; consult the official contract before choosing one.

Run it locally

Run this complete source locally with PHP 8.2 or newer. Save it using the filename shown and run the command below. PHP is not currently available in Bhylu’s browser playground. Apache and MySQL are not needed for an ordinary CLI example.

php -l ref-files.php
php ref-files.php

Download this source as a local PHP lab file. Keep lab files separate from the Bhylu project and production data.

Example

<?php
declare(strict_types=1);

$stream = fopen("php://temp","w+");
if ($stream === false) throw new RuntimeException("No stream");
try { fwrite($stream,"Tool note"); rewind($stream); echo stream_get_contents($stream), "\n"; } finally { fclose($stream); }

Expected result

Tool note

The temporary stream is allocated and closed by one block. Rewinding changes its current read position. This example does not require access to a personal path or a production upload directory and does not establish the permissions of a later permanent storage design.

Contracts to check

Related API names

This alphabetic inventory helps locate related calls. Availability was checked in the review runtime; it is not a recommendation to use every API or a claim that every overload/function was executed. Read the official entry for version, extension, failure and security details.