Subject: Re: bug#12689: 24.2; Eshell ${cmd} substitution

From: Samer Masterson <[email-masked]>
Date: Wed, 04 Mar 2015 04:14:07 -0800

On Tue, Mar 3, 2015 at 7:54 AM, Eli Zaretskii <[email-masked]> wrote:
> Does this have any effect on the feature where Eshell can run several
> commands simultaneously via a shell-like pipe?
> 
> Thanks.

I don't know what feature you're describing. Here is the output from 
running regular pipes:

~ $ echo hello | /bin/echo there | /bin/echo hey | echo hi # Without 
patch
hi
hey
~ $ echo hello | /bin/echo there | /bin/echo hey | echo hi # With patch
hi
hey
there
hello

First, we should ignore the fact that echo does nothing with stdin, and 
the above commands print "hi" in bash. I do not understand why the 
command without the patch only prints out "hey\nhi", but it printed 
that consistently on my computer. The second output is incorrect (or at 
the very least unexpected?), but less incorrect than the first. If this 
is what you were talking about, then the commands may have appeared to 
be simultaneous because they were racing, but I'm not sure if that's 
intentional.