(PHP 4, PHP 5, PHP 7, PHP 8)
realpath — Returns canonicalized absolute pathname
$path): string|false
realpath() expands all symbolic links and
resolves references to /./, /../ and extra / characters in
the input path and returns the canonicalized
absolute pathname.
pathThe 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:
On Windows, junctions and symbolic links to directories are only expanded by one level.
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.
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'), PHP_EOL;
echo realpath('C:\Program Files\\'), PHP_EOL;
?>
The above example will output:
C:\WINDOWS\System32 C:\Program Files