Re: [9fans] ls, rc question

[rsc@swtch.com]

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if you want, you can think of this as a bug in read(2):
if a file is covered up, it should be completely hidden.
it turns out that actually implementing this is quite hard,
that it doesn't really break much (you've found about
all of it!) to leave it as is, and that it results in things
like /bin/ls giving interesting information about the union.

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From: David Tolpin <dvd@davidashen.net>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] ls, rc question
Date: Fri, 19 Mar 2004 03:00:51 +0400 (AMT)
Message-ID: <200403182300.i2IN0p5T095713@adat.davidashen.net>


I am not asking why there are two file names in the directory listing. I understand it.

I think that behaviours of rc and ls are confusing. I would either expect rc's globbing
to only match one path name, or ls to display all files.

man rc says 'A pattern is replaced by a list of arguments, one
for each path name matched'. Not for each directory entry. For
each path name. There is one path name /dev/user for two files.

cpu% ls -q /dev|grep user
(0000000000000015 0 00) /dev/user
(000000000000000c 0 00) /dev/user

Globbing expands this to two elements:

cpu% echo /dev/user*
/dev/user /dev/user

I think this is not what the manual says. 

Then,

cpu% ls -q /dev/user*
(0000000000000015 0 00) /dev/user
(0000000000000015 0 00) /dev/user

I understand why it is so. But I think that consistency is sacrificed
for simplicity. Either rc should do what the manual says and return
one match for /dev/user* (so that /dev/user* and /dev/user is the same
thing), or ls -q /dev/user should recursively list all directory
entries matching the path name.

David Tolpin