On Saturday 15 May 2010 19:57, Cristian Ionescu-Idbohrn wrote:
> On Sat, 15 May 2010, Denys Vlasenko wrote:
>
> > On Friday 14 May 2010 21:44, Cristian Ionescu-Idbohrn wrote:
> > > On Fri, 14 May 2010, Denys Vlasenko wrote:
> > >
> > > > I did discover a lot of interesting details about shells
> > > > while hacking on them. One is that bare "read"
> > > > is NOT the same thing as "read REPLY"! Look at this:
> > > >
> > > > $ echo " foo b\ar " | { read -r; echo "[$REPLY]"; }
> > > > [ foo b\ar ]
> > >
> > > $ dash -c 'echo " foo b\ar " | { read -r; echo "[$REPLY]"; }'
> > > read: 1: arg count
> > > []
> >
> > They are not bash compat :)
>
> Pick any one shell as _the_ reference shell and compare it with all other
> major shells. The in"compat"ibilities (bash or not bash) will be
> noticable.
But bash is de-facto standard Linux shell. Not ksh or zsh.
Therefore, it makes sense to match bash behavior
where it does not require major coding.
Sure, I can stop using "read" without parameter.
But this does not affect many other shell scripts out there -
hundreds or thousands of them use this construct.
If, instead, we patch dash to understand "read" without parameter
(which can't be too hard), all those scripts start working.
> But what is an input line?
>
> Is this an input line?
>
> bash$ read -r REPLY <<EOF
> > foo b\ar
> > EOF
> bash$ echo "[$REPLY]"
> [foo b\ar]
Yes.
> Is this an input line too?
>
> bash$ echo " foo b\ar " | { read REPLY; echo "[$REPLY]"; }
> [foo bar]
Yes.
> What about this?
>
> dash$ read -r REPLY <<EOF
> > foo b\ar
> > EOF
> dash$ echo "[$REPLY]"
> [foo br]
Bug.
--
vda
_______________________________________________
busybox mailing list
[email protected]
http://lists.busybox.net/mailman/listinfo/busybox
