From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <38f6304f0448ab7a2c49acc0d6293169@plan9.bell-labs.com>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] bind -c
From: "Russ Cox" <rsc@plan9.bell-labs.com>
In-Reply-To: <Pine.LNX.4.30.0303071558540.8127-100000@athena>
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Date: Fri,  7 Mar 2003 16:07:18 -0500
Topicbox-Message-UUID: 7d250b56-eacb-11e9-9e20-41e7f4b1d025

> Why shouldn't this work?
> 	term% mkdir replica; cd replica
> 	term% bind -c . .
> 	term% bind -a /sys/src/cmd/replica .
> 	term% cp mkfile . #obtain a local copy
> 	cp: mkfile and mkfile are the same file

Because the first thing cp does is basically

	ls -lq mkfile ./mkfile

and discovers that the source and destination
are the same.  Binding with -c only changes 
where _new_ files are created.  When you create()
an existing file that directory entry is used.

In this case it's probably significantly easier just to

	mkdir replica
	cp /sys/src/cmd/replica/* replica

and not worry about union directories.

What I usually do for things like this is:

	cd /sys/src/cmd/replica
	bind -bc $home/replica .

and then 

	cp mkfile $home/replica
	etc.

to make copies of the files I want to change.

Russ