Re: Two esoteric zsh questions

["Bart Schaefer" <schaefer@xxxxxxxxxxxxxxxxxxxxxxx>]

On Sep 5,  1:21pm, Jerry Peek wrote:
>
> (Is *any* zsh question esoteric?  Or are *all* zsh questions? ;-)

Both.

> 1) Can anyone explain the difference in the following two cases?  The
> first sets a shell variable; the second sets an environment variable.

Zefram answered this.

> 2) I wanted to compare the values of $whoson and $WHOSON.

You mean you wanted to see the differences, not just know whether there
are differences?  When I hear "compare the values" I think of

	[[ $whoson == $WHOSON ]]

> I couldn't think of a way to use two <<< operators

Right; if you did so, multios would concatenate the two inputs.

> 	% diff - <(echo $WHOSON) <<<$whoson
> 	%
> 
> Does anyone know a cleaner way to do that?

Aside from using "print -r --" in place of "echo", so that backslashes or
leading hyphens in $WHOSON won't cause problems, the only thing that comes
to mind is

	diff <(<<<$whoson) <(<<<$WHOSON)

which is really mostly same as

> 	% diff - <(cat <<<$WHOSON) <<<$whoson

except that zsh implements the "cat" internally, and you can give the args
in the same order that they'll appear in the diff output, which is slightly
more understandable.