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. Trailing delimiters, such as \ and /, are also removed.

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:
For case-insensitive filesystems realpath may or may not normalize the character case.

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.
5.2.1	Prior to this version, realpath returned `FALSE` if `path` is an empty string or `NULL`.

Examples

Example #1 realpath example


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

echo realpath('/tmp/') . PHP_EOL;
?>

The above example will output:

/etc/passwd
/tmp

Example #2 realpath on Windows

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


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

echo realpath('C:\Program Files\\');
?>