Returns canonicalized absolute pathname
realpath ( string $path ) : string
The path being checked.
Note: Whilst a path must be supplied, the value can be an empty string. In this case, the value is interpreted as the current directory.
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: The function realpath() will not work for a file which is inside a Phar as such path would be a virtual path, not a real one.
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.
<? chdir('/var/www/'); echo realpath('./../../etc/passwd') . PHP_EOL; echo realpath('/tmp/'); ?>
<? echo realpath('/windows/system32') . PHP_EOL; echo realpath('C:\Program Files\'); ?>
C:\WINDOWS\System32 C:\Program Files