Re: Testing if there is data on stdin?

[Sebastian Stark <seb-zsh@xxxxxxxxxxx>]

On 18.09.2009, at 01:47, Mikael Magnusson wrote:

> 2009/9/18 Lloyd Zusman <ljz@xxxxxxxxxx>:
> > Is there a way in zsh to test whether there is at least one byte of  
> > data
> > waiting to be read from stdin without actually reading that data?
>
> You can either use
> zmodload zsh/zselect
> zselect -t0 0
> or
> read -t0

I tried both and noticed a difference:

% print foo | { cat }
foo
% print foo | { read -t0; cat }
% print foo | { zmodload zsh/zselect; zselect -t0 0; cat }
foo

Can anyone explain the difference?