[[!meta copyright="Copyright © 2010, 2011 Free Software Foundation, Inc."]] [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable id="license" text="Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled [[GNU Free Documentation License|/fdl]]."]]"""]] A *file descriptor* is a [[concept]] of [[UNIX]], and represents a non-[[persistent|persistency]] handle to an object (a file, for example). With respect to specific aspects, it is comparable to a [[capability]]. This is detailed in {{$capability#wikipedia_capability-based_security}}. In a GNU Hurd system, the concept of file descriptors is based on object handles (through [[Mach ports|microkernel/mach/port]]), and is [[implemented in glibc|glibc/file_descriptor]].