From e1a385ab400fa2082caddde001c8c9e1db0c1ded Mon Sep 17 00:00:00 2001 From: "Andrew M. Kuchling" Date: Wed, 31 Aug 2005 13:50:17 +0000 Subject: Explain what file descriptors are; this change has been sitting in my tree for a while --- Doc/lib/libos.tex | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/Doc/lib/libos.tex b/Doc/lib/libos.tex index dc621dd..2fbecfa 100644 --- a/Doc/lib/libos.tex +++ b/Doc/lib/libos.tex @@ -427,8 +427,15 @@ functions have a different order. \subsection{File Descriptor Operations \label{os-fd-ops}} -These functions operate on I/O streams referred to -using file descriptors. +These functions operate on I/O streams referenced using file +descriptors. + +File descriptors are small integers corresponding to a file that has +been opened by the current process. For example, standard input is +usually file descriptor 0, standard output is 1, and standard error is +2. Further files opened by a process will then be assigned 3, 4, 5, +and so forth. The name ``file descriptor'' is slightly deceptive; on +{\UNIX} platforms, sockets and pipes are also referenced by file descriptors. \begin{funcdesc}{close}{fd} -- cgit v0.12