file descriptor

from The Free On-line Dictionary of Computing (8 July 2008)

file descriptor

   <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)