PHP Manual: Returns canonicalized absolute pathname

Description

string realpath ( string $path )

realpath expands all symbolic links and resolves references to '/./', '/../' and extra '/' characters in the input path and returns the canonicalized absolute pathname.

Parameters

path

The path being checked.

Note:
Whilst a path must be supplied, the value can be blank or NULL In these cases, the value is interpreted as the current directory.

Return Values

Returns the canonicalized absolute pathname on success. The resulting path will have no symbolic link, '/./' or '/../' components.

realpath returns FALSE on failure, e.g. if the file does not exist.

Note:
The running script must have executable permissions on all directories in the hierarchy, otherwise realpath will return FALSE.

Note: Because PHP's integer type is signed and many platforms use 32bit integers, some filesystem functions may return unexpected results for files which are larger than 2GB.

Changelog

Version	Description
5.3.0	Prior to this release, if only the last `path` component did not exist, realpath would not fail on *BSD systems. realpath now fails in this case.
5.0.0	Prior to this release, a blank or `NULL` `path` would cause realpath to return the directory name of the script.

Examples

Example #1 realpath example


<?php
chdir('/var/www/');
echo realpath('./../../etc/passwd');
?>

The above example will output:

/etc/passwd

Example #2 realpath on Windows

On windows realpath will change unix style paths to windows style.


<?php
echo realpath('/windows/system32');
?>