Short for
end-of-file mark, a
special character or sequence of
characters that marks the end of a
file.
Operating systems need to keep track of where every file ends. There are two techniques for doing this: One is to put a special end-of-file mark at the end of each file. The other is to keep track of how many characters are in the file.
In many operating systems, including DOS and OS/2, the end-of-file mark is CTRL -Z.