file.control.block

defines a file control block.

Every file on the system has a special frame (or frames) attached to it called a 'file control block' or 'fcb'. These frames contain information about the file, including index pointers and their compiled a (algebraic) processing codes, the file 'd-pointer' information for editing, pointers and workspace used by the system when calling Pick/BASIC subroutines from file dictionaries.

Also contained in this 'file control block' are important flags and fields indicating that the file is open, closed, in the process of being deleted, etc. This provides the ability to protect the system from potenitally disastrous situations, such as the case of one process deleting a file while another process is using the same file.