How does php turn off automatic filtering of input and output

  question
<?php
set_magic_quotes_runtime(false);
ini_set('magic_quotes_gpc',0);
ini_set('magic_quotes_runtime',0);

echo $_GET['a'];

In this way. Visiting a.php? a=1’\
The output is still l \ \

How can it close automatically?

Do not use stripslashes

What the fuck …

get_magic_quotes_gpc