php man page for posix_ttyname

POSIX_TTYNAME(3)							 1							  POSIX_TTYNAME(3)

posix_ttyname - Determine terminal device name

SYNOPSIS
       string posix_ttyname (mixed  $fd)

DESCRIPTION
	Returns a string for the absolute path to the current terminal device that is open on the file descriptor $fd.

PARAMETERS
	      o $fd
		-  The	file  descriptor,  which  is  expected to be either a file resource or an integer. An integer will be assumed to be a file
		descriptor that can be passed directly to the underlying system call.  In almost all cases,  you  will	want  to  provide  a  file
		resource.

RETURN VALUES
	On success, returns a string of the absolute path of the $fd. On failure, returns FALSE

PHP Documentation Group 													  POSIX_TTYNAME(3)