(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
ftok — Convert a pathname and a project identifier to a System V IPC key
The function converts the filename 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.
filenameproject_idOn success the return value will be the created key value, otherwise -1 is returned.