See part 23 of the advanced bash scripting guide.
In short, the effect of the <( x ) and >( y ) syntaxes are the following:
You put them in your command line where a filename is expected
Enclosed command will either
- redirect stdout to (
<(x)), or
- read stdin from (
>(y))
a temporary file (or a named pipe, bash will manage it), the name of which will be given to your external command.
