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Filesystem Functions
PHP Manual

# realpath

(PHP 4, PHP 5)

realpath — 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');
?>`

The above example will output:

    C:\WINDOWS\System32

### See Also

- basename() - Returns trailing name component of path
- dirname() - Returns parent directory's path
- pathinfo() - Returns information about a file path

realpath_cache_size
rename
Filesystem Functions
PHP Manual