Accessing various I/O streams
PHP provides a number of miscellaneous I/O streams that allow access to PHP's own input and output streams, the standard input, output and error file descriptors, in-memory and disk-backed temporary file streams, and filters that can manipulate other file resources as they are read from and written to.
php://stdin, php://stdout and php://stderr php://stdin, php://stdout and php://stderr allow direct access to the corresponding inp