programming, operating system An integer that identifies an open
file within a
process. This number is obtained as a result of opening a file. Operations which read, write, or close a file would take the file descriptor as an input parameter.
In many
operating system implementations, file descriptors are small integers which index a table of open files. In
Unix, file descriptors 0, 1 and 2 correspond to the standard input, standard output and
standard error files respectively.
See
file descriptor leak.
(1998-02-06)