bug?

bug?

[Russell Davies]

; mkdir $HOME/e
; cdpath=$HOME
; cd /
; cd e
/home/blah/e

ok, all is well. Suppose now I want to suppress the output of the cd e.

; cd /
; cd e >/dev/null
; pwd
/

huh? I haven't had time to dig too deeply but if someone else has looked
at it before, I won't bother.

r.

Re: bug?

[Carlo Strozzi]

On Mon, May 28, 2001 at 03:47:00AM -0500, Russell Davies wrote:
| 
| ; mkdir $HOME/e
| ; cdpath=$HOME
| ; cd /
| ; cd e
| /home/blah/e
| 
| ok, all is well. Suppose now I want to suppress the output of the cd e.
| 
| ; cd /
| ; cd e >/dev/null
| ; pwd
| /

I believe the '>' redirection causes cd to be executed in a subshell,
and when the latter dies so does the cd effect.

bye,
carlo
-- 
Carlo Strozzi
TeXne.COM - Open Consulting
Mail: carlos@texne.com  Voice: (+39)0523-883732  Fax: (+39)0523-840980

Re: bug?

[Paul Haahr]

--- Russell Davies <russell.davies@db.com> wrote:
> 
> ; mkdir $HOME/e
> ; cdpath=$HOME
> ; cd /
> ; cd e
> /home/blah/e
> 
> ok, all is well. Suppose now I want to suppress the output of the cd
> e.
> 
> ; cd /
> ; cd e >/dev/null
> ; pwd
> /
> 
> huh? I haven't had time to dig too deeply but if someone else has
> looked at it before, I won't bother.

I don't have a Unix box in front of me to test or access to the source, but
rc commands with redirected I/O run in subshells;  thus, the directory of
your child process is changed, but not the parent process.

(I think we fixed that in es by remapping file descriptors all over the
place and forking way late in the game.)

--p

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Re: bug?

[Byron Rakitzis]

Whether it's a bug depends on your expectations -- but redirections
happen in a subshell and you'd have to know that.

You could do:

exec > /dev/null
cd e
exec > /dev/tty