(PHP 4, PHP 5)
realpath — Returns canonicalized absolute pathname
realpath() expands all symbolic links and resolves references to '/./', '/../' and extra '/' characters in the input path . and return the canonicalized absolute pathname.
The path being checked.
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. On BSD systems realpath() doesn't fail if only the last path component doesn't exist, while other systems will return FALSE.
Example#1 realpath() example
<?php
chdir('/var/www/');
echo realpath('./../../etc/passwd');
?>
The above example will output:
/etc/passwd