using environment variables in XML conf files

[Andrew McDermott]

I have the following path hard-coded for hadoop.tmp.dir in
conf/core-site.xml:

    <configuration>
      <property>
        <name>hadoop.tmp.dir</name>
        <value>/home/aim/tmp/hadoop-${user.name}</value>
      </property>
    </configuration>

Is it possible to replace the "/home/aim" with a substitutable version
$HOME?  On a whim I tried ${env.home} but that didn't work...

-- 
andy