File Operations and structures
A file is an abstract data type.
Operations: open, close, create, destroy, copy, rename, list, read, write, update, insert item, delete item, size,...
Open file table: Table containing information about open files. When a file operation is requested, an index into this table is used for locating the file. When a file is closed the entry is removed from the table.
Current file pointer: Last read/write location is kept as a current-file-position pointer. Each process using the file has a unique pointer. Where is it kept?
File open count: Number of opens done on a given file. To allow deletion from Open file table, once the count reaches 0.