Path: utzoo!yunexus!geac!syntron!jtsv16!uunet!auspex!guy
From: guy@auspex.UUCP (Guy Harris)
Newsgroups: comp.unix.questions
Subject: Re: Child access to parent files opened AFTER fork/exec.
Message-ID: <347@auspex.UUCP>
Date: 29 Oct 88 03:55:15 GMT
Article-I.D.: auspex.347
References: <351@marob.MASA.COM>
Reply-To: guy@auspex.UUCP (Guy Harris)
Organization: Auspex Systems, Santa Clara
Lines: 12

>Given that a child process inherits the open files of its parent,
>is there any way for the child to access a file opened by the
>parent subsequent to the child being exec'd ?

Yes.  It can reopen those files itself, assuming the files have a file
name, it knows the file name, and opening something with that name gives
it a descriptor for the same file (which needn't be true if the file is
a special file that refers to a "clone" device).

Alternatively, some UNIX IPC mechanisms, namely UNIX-domain sockets in
4.[23]BSD and "stream pipes" in System V Release 3.x, permit a process
to pass file descriptors to another process.