Path: utzoo!attcan!lsuc!eci386!ecicrl!clewis
From: clewis@ecicrl.UUCP (Chris Lewis)
Newsgroups: comp.unix.wizards
Subject: Re: ls -A
Message-ID: <698@ecicrl.UUCP>
Date: 8 Oct 89 20:43:30 GMT
References: <15@minya.UUCP> <14611@bloom-beacon.MIT.EDU> <1989Oct6.201107.9465@eci386.uucp> <1989Oct7.032907.27496@rpi.edu>
Reply-To: clewis@ecicrl.UUCP (Chris Lewis)
Distribution: na
Organization: Elegant Communications Inc., Ferret Division, Toronto, Canada
Lines: 31

In article <1989Oct7.032907.27496@rpi.edu> tale@pawl.rpi.edu (David C Lawrence) writes:
>In <1989Oct6.201107.9465@eci386.uucp> jmm@eci386.uucp (John Macdonald) writes:
>John> Like all things, treating .* files specially has advantages and
>John> disadvantages.  Some form of special treatment *was* necessary -
>John> otherwise "rm *" would remove "." and ".."!
>
>No it wouldn't.   rm already does special treatment of `.' and `..'.
>Some form of special treatment by shell expansion of * wasn't
>"necessary" at all.

I think you missed the point.  If "*" expanded to include all . files,
by the principle of least surprise, then every utility would *have* to
*try* to act on "." and "..".  Eg: ed (oof!), cat (ugh!), tar (ouch!), and 
unlink (YIPES!)

Special casing "." files at command interpreter level is analogous to 
features in a lot of other operating systems.  Eg: minidisk extension 0 in 
VM/CMS (ala PROFILE EXEC A0).

I suspect that when this portion of the file system was designed, and
directory self and parent links were thought out, the idea of using
the "." prefix to *generally* hide files lit the proverbial light bulb as
a nice touch "serendipity-wise".  Almost 20 years later it still sounds
like a good idea....

Special casing "ls -A" for root is a botch though.
-- 
Chris Lewis, Elegant Communications Inc.
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