Whoever out there needs to find something in a jar under linux:
for i in `find $JBOSS_HOME -name \*.jar`; do echo $i; jar tf $i | grep ServiceMBeanSupport; done
Because jar does not take a list of jar's to explode. The above builds up a list of all jars below $JBOSS_HOME and passes it one by one into $i. The script echo's $i and the grep echo's something if it finds the required text. One line above the grep's output, you'll find the path of the jar that contains it.
Don't forget to set JBOSS_HOME to the appropriate directory and to substitute "ServiceMBeanSupport" with the name you're searching for.
(Works well under cygwin)