$re = '/^(?:[a-zA-Z]:)?(?:[\\\\\/][a-zA-Z0-9_. -]*)+$/m';
$str = 'C:\\Deal\\v6\\.git\\logs
C:\\Deal\\v6\\
F:\\Deal\\v6\\compil.log
F:/Deal/v6/comp-il.log
F:/De al/v6/compil.log
F:/De al/v6/comp il.log
/c/Deal/v6
/c/Deal/v6\\
C:\\
/
/c
\\\\dwi3342\\Deal\\v6\\comp-il.log
//dwi3342/Deal/v6/compil.log
F:/Deal/../compil.log
GG:/Deal/v6/comp-il.log
^(.*\\/)([^\\/]*)$
((?:[^\\/]*\\/)*)(.*)
([\\/\\\\][^\\/\\\\]*$)
^(.*(?:\\/|\\\\))([^\\/\\\\]*)$
^((?:[^\\/\\\\]*\\/\\\\)*)(.*)$
^(?:[a-zA-Z]:[\\\\\\/]|[\\\\\\/])(?:[a-zA-Z0-9_. -]+[\\\\\\/])*(?:[a-zA-Z0-9_. -]+)?$
^(?:[a-zA-Z]:)?(?:[\\\\\\/][a-zA-Z0-9_. -]*)+$
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php