(PHP 4, PHP 5, PHP 7, PHP 8)
posix_mkfifo — Create a fifo special file (a named pipe)
$filename, int $permissions): bool
   posix_mkfifo() creates a special
   FIFO file which exists in the file system and acts as
   a bidirectional communication endpoint for processes.
  
filename
       Path to the FIFO file.
      
permissions
       The second parameter permissions has to be given in
       octal notation (e.g. 0644). The permission of the newly created
       FIFO also depends on the setting of the current
       umask(). The permissions of the created file are
       (mode & ~umask).
      
   Returns true on success or false on failure.