Conditional task execution

[David Corbin]

The javac task has some conditionality in it, I think, that says "don't
compile those class files that haven't changed".  I want to find a way
to do something similar for other tasks/targets.  

For example, if I have something like this:

<target name="foo">
        <exec executable="foomaker">
                <arg>foosrc</arg>
        </exec>
</target>

How do I get it to ONLY run when foosrc is newer than foo?
Thanks.
-- 
David Corbin            
Mach Turtle Technologies, Inc.
http://www.machturtle.com
[EMAIL PROTECTED]