PHP fopen() Function – Description, Parameters, Return Value, and Usage Examples

fopen() opens a file or URL and binds it to a stream, returning a resource handle on success or FALSE on failure.

Parameters

filename – The path or URL to open. If it matches a registered protocol (e.g., http://, ftp://), PHP uses the corresponding wrapper; otherwise it treats it as a local file.

mode – A string that specifies the access type. Supported values are: 'r' – read‑only, pointer at start 'r+' – read/write, pointer at start 'w' – write‑only, truncate to zero, create if missing 'w+' – read/write, truncate to zero, create if missing 'a' – write‑only, pointer at end, create if missing 'a+' – read/write, pointer at end, create if missing 'x' – create and write, fail if file exists 'x+' – create and read/write, fail if file exists

use_include_path – Optional boolean; if TRUE, PHP also searches the include_path for the file.

context – Optional stream context resource (available since PHP 5.0.0).

Return value

On success, fopen() returns a file‑pointer resource; on failure it returns FALSE.

Example usage

<?php
$handle = fopen("/home/rasmus/file.txt", "r");

$handle = fopen("/home/rasmus/file.gif", "wb");

$handle = fopen("http://www.example.com/", "r");

$handle = fopen("ftp://user:[email protected]/somefile.txt", "w");
?>

The examples demonstrate opening a local file for reading, opening a local file for binary writing, reading from a remote HTTP resource, and writing to a remote FTP resource.