Ipconfig command (ran thru the process) not getting terminated

Question

We are working on a web based application that requires running ipconfig /all command as a process from Java class to fetch the MAC address.
Using the tool called "handle.exe", what we have found is that even after the process is destroyed, the ipconfig process exists & eventually there are lots of such handles for ipconfig.
We are using jdk 1.4.2_03 with tomcat 4.1.27. I am copying the piece of code below to give an idea of what we are doing:
Runtime runtime = Runtime.getRuntime();
proc = runtime.exec( "ipconfig /all" );
BufferedReader reader = new BufferedReader(new InputStreamReader(proc.getInputStream()));
try
String line;
// On Windows, read multiple lines until the Physical Address is found
while ((line = reader.readLine()) != null)
// logic to retrieve the MAC address from the output above
catch (IOException e)
// print the message
proc.destroy();
Any help/pointers will be appreciated.
Thanks in advance.. SDM

Answer 1

I've found the same problem with a similar peice of code.
One thing you can do to reduce the leakage is to explicitly close the process object's input, output & error streams, but that still leaves a leak of one handle per exec call.
This does seem to be an ipconfig thing rather than a java thing as I don't get the same leak with other commands.
I used the free process explorer from http://www.sysinternals.com/ when investigating this problem