PHP 3.0.13 and up,
php://output and php://input
since PHP 4.3
php://stdin
php://stdout
php://stderr
php://output
php://input
php://stdin, php://stdout and
php://stderr allow access to the corresponding input or
output stream of the PHP process.
php://output allows you to
write to the output buffer mechanism in the same way as
print() and echo().
php://input allows you to read
raw POST data. It is a less memory intensive alternative to
$HTTP_RAW_POST_DATA and does not
need any special php.ini
directives.
php://stdin and php://input are read-only, whereas php://stdout,
php://stderr and php://output
are write-only.