On Thu, Aug 14, 2008 at 12:20 PM, kazumi iwane <[EMAIL PROTECTED]> wrote:
> if you want to delay the expansion of an env var until fn invocation,,use
> eval.
>
> % fn foo {eval echo $$bar}
sorry, but that's so, so wrong.
1) $$bar gives the value of the variable
named by the contents of the variable bar,
so that the above, given that $bar contains 'baz'
will echo $baz.
2) $$bar above is evaluated _before_ eval is invoked,
so the line is not very different from {echo $$bar}, except that
if $$bar holds any syntax characters they'll get interpreted by the shell.
it's almost never necessary to use eval with rc.
3) expansion of env. vars *is* delayed until fn invocation.
e.g.
% fn foo {echo $bar}
% bar = baz
% foo
baz
%
it just seems as if the local variable assignment isn't propagated
into the fn context. i don't have time to look into it now (i really
shouldn't be spending time writing this email, but i couldn't resist the bait).
rog.
