Re: Odd behavior using MULTIOS

[Clinton Bunch <cdbunch@zentaur.org>]

Another thing I noticed is that MULTIOS doesn't appear to work with exec

i.e.

exec 3>/tmp/test1 3>/tmp/test2

causes the script to hang.

I'm not sure why.  Am I just being dense today?

On 11/11/2020 10:42 AM, Peter Stephenson wrote:
>> On 11 November 2020 at 16:25 Clinton Bunch <cdb_zsh@zentaur.org> wrote:
>> Is this the expected behavior?
>>
>> setopt MULTIOS
>> {
>> print -u3 "Testing"
>> print  "Second Testing"
>> } 3>&1 3>/tmp/test
>> % zsh test.zsh
>> Second Testing
>> Testing
> You mean the ordering?  Yes, as documented "the shell opens the file descriptor as a pipe
> to  a process that copies its input to all the specified outputs".  So this isn't
> synchronous within the current shell and you can't rely on ordering.  You'll note
> there's nothing there to determine whether the downstream pipe component performs
> a write to the terminal before the main shell does --- think of it a bit like
>
> { print Testing; print "Second Testing" >/dev/tty } | tee /dev/tty /tmp/test
>
> --- although I'm not guaranteeing they're identical and clearly there's room
> for lots of things in the two processes to affect the ordering.
>
> pws
>