Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!lll-winken!uunet!mcvax!ukc!kl-cs!pc
From: pc@cs.keele.ac.uk (Phil Cornes)
Newsgroups: comp.unix.questions
Subject: Re: Named Pipe Creation
Message-ID: <653@kl-cs.UUCP>
Date: 3 Jul 89 14:22:51 GMT
References: <163@cerc.wvu.wvnet.edu.edu>
Organization: University of Keele, England
Lines: 29

From article <163@cerc.wvu.wvnet.edu.edu>, by drs@cerc.wvu.wvnet.edu (Darrell Schiebel):
> I am attempting to create a named pipe which several different users
> can read from and write to, but ......
> 
> the system creates a pipe with owner r/w, group r, and world r.  The
> protection I was expecting is owner r/w , group r/w, wnd world r/w.
> 

The simplest explanation for this is that somewhere in your login sequence
the command:

	umask 022

gets executed. What umask(1) does is to specify a pattern of permission bits
that will definitely be reset to 0 whenever a file is created whatever file
permission bits are given in the system call that creates the file.

What you must do is to issue a new umask(1) command (so that the group and
world write permission bits are not reset) before you run your program, or
issue a umask(2) system call from within your program to achieve the same
effect.


Phil Cornes          I just called to say .....
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