(PHP 4 >= 4.2.0, PHP 5)
ftok — Convert a pathname and a project identifier to a System V IPC key
$pathname
   , string $proj
   )
   The function converts the pathname of an existing
   accessible file and a project identifier into an
   integer for use with for example
   shmop_open() and other System V IPC keys. 
  
pathnamePath to an accessible file.
projProject identifier. This must be a one character string.
On success the return value will be the created key value, otherwise -1 is returned.