test script:
<?php
// windows
$path_win = 'C:\WINNT\anything.txt';
echo "\n".'dirname("'.$path_win.'"):'."\n";
var_dump(dirname($path_win));
echo "\n".'basename("'.$path_win.'"):'."\n";
var_dump(basename($path_win));
echo "\n".'pathinfo("'.$path_win.'"):'."\n";
var_dump(pathinfo($path_win));

// *nix
$path_nix = '/etc/anything.conf';
echo "\n".'dirname("'.$path_nix.'"):'."\n";
var_dump(dirname($path_nix));
echo "\n".'basename("'.$path_nix.'"):'."\n";
var_dump(basename($path_nix));
echo "\n".'pathinfo("'.$path_nix.'"):'."\n";
var_dump(pathinfo($path_nix));
?>

output:

dirname("C:\WINNT\anything.txt"):
string(1) "."

basename("C:\WINNT\anything.txt"):
string(21) "C:\WINNT\anything.txt"

pathinfo("C:\WINNT\anything.txt"):
array(3) {
  ["dirname"]=>
  string(1) "."
  ["basename"]=>
  string(21) "C:\WINNT\anything.txt"
  ["extension"]=>
  string(3) "txt"
}

dirname("/etc/anything.conf"):
string(4) "/etc"

basename("/etc/anything.conf"):
string(13) "anything.conf"

pathinfo("/etc/anything.conf"):
array(3) {
  ["dirname"]=>
  string(4) "/etc"
  ["basename"]=>
  string(13) "anything.conf"
  ["extension"]=>
  string(4) "conf"
}