Hi,
Welcome to JavaRanch!
Please don't post the same question to more than one forum; see our explanation
here. I've deleted the other copy of this
thread.
As to your question: same as you'd do it on the command line: by using a quoted or escaped blank string. Two single quotes ought to do fine.
Alternatively, there are forms over Runtime.exec() which take arrays of Strings as arguments, rather than a single String; use one of those. This will allow you to pass an empty String as an argument. Again, this is what you'd typically do when calling exec() from a C program.
[ January 02, 2007: Message edited by: Ernest Friedman-Hill ]