Runtime.exec( ) exception

Question

Hi All!
Could you please look at this code and give me an idea what could be wrong.
Thanks
String commandStr = "move " + args[0] + " " + args[1];
           System.out.println( commandStr );
           try {
                Process proc = Runtime.getRuntime().exec( commandStr );
                int retValue = proc.exitValue();
                System.out.print ( "Command : " + commandStr );
                System.out.println( "was executed with exit value : " + retValue );
           catch (Throwable t) {
                System.out.println("Caught an exception ");
                t.printStackTrace();
output
move C:/C++ C:/MovedStuff
java.io.IOException: CreateProcess: move C:/C++ C:/MovedStuff error=2
Caught an exception
     at java.lang.Win32Process.create(Native Method)
     at java.lang.Win32Process.<init>(Unknown Source)
     at java.lang.Runtime.execInternal(Native Method)
     at java.lang.Runtime.exec(Unknown Source)
     at java.lang.Runtime.exec(Unknown Source)
     at java.lang.Runtime.exec(Unknown Source)
     at java.lang.Runtime.exec(Unknown Source)
     at FileCopier.main(FileCopier.java:92)

Answer 1

There are more things to consider if you are going to run other commands. Mainly, you have to read what the command writes to STDOUT and STDERR otherwise your program will just hang.
I forget where I found my information but I just searched the web for "StreamGobbler" and found www.experts-exchange.com/Developer/ Programming/Q_20428597.html which contains a good code snippet and looks a lot like the code I have.
I've only done this on Windows but it should work on Linux as well. You'll have to have separate code for each operating system, of course, as Java does not know what you are trying to execute it merely passes the command to the shell.
Good luck.
Barry