It occurred to me that Johnny Billquist wrote in gmane.os.netbsd.general:

> Just try something like
>
> cat - file - < file1 < file2
>
> and check if file is located between file1 and file2.
>

It doesn't:

atlas% echo $SHELL
/usr/pkg/bin/zsh
atlas%cat - file - <file1 <file2
file1
file2
file