Using ProcessBuilder to execute multiple commands.

Question

I am having issues getting ProcessBuilder to execute multiple commands in windows.
As an example I would like to execute "dir /w" fallowed by "java.exe some.App arg1 arg2".
I can accomplish this from the command line by using "&".
Example: dir /w & java.exe some.App arg1 arg2 Or: dir /w & dir /c"
For internal commands (i.e. dir and cd) I know that commands in the array being passed to ProcessBuilder must be formatted like {"dir /w", "dir /c"}
see post: [http://www.java-tips.org/java-se-tips/java.util/from-runtime.exec-to-processbuilder.html]
Here is an example of one of the many things I have tried:
{code}
String[] commands = new String[]{"dir /w", "&", "java.exe", "some.App", "arg1", "arg2"};
ProcessBuilder pb = new ProcessBuilder(commands);
pb.start();
{code}
Any other ideas / what am I doing wrong?
Edited by: brianjbrady on May 7, 2009 4:49 PM
Edited by: brianjbrady on May 7, 2009 4:50 PM

Answer 1

brianjbrady wrote:
You can run dir all day long without using cmd.exe. Try it. It works for me.Perhaps you have cygwin in your path.
How are you running dir out of interest (and don't say with a DOS window ;)
import java.io.*;
import java.util.Arrays;
public class Main {
    public static void main(String... args) throws IOException {
        run("dir");
        run("dir.exe");
        run("cmd", "/c", "dir");
        run("c:\\cygwin\\bin\\dir");
    private static void run(String... command) throws IOException {
        try {
            ProcessBuilder pb = new ProcessBuilder(command);
            pb.redirectErrorStream(true);
            Process p = pb.start();
            InputStream is = p.getInputStream();
            System.out.println("\nCommand " + Arrays.asList(command) + " reported");
            int b;
            while ((b = is.read()) >= 0)
                System.out.write(b);
            is.close();
            p.destroy();
        } catch (IOException e) {
            System.err.println("\nCommand " + Arrays.asList(command) + " reported " + e);
}Prints
Command [dir] reported java.io.IOException: Cannot run program "dir": CreateProcess error=2, The system cannot find the file specified
Command [dir.exe] reported java.io.IOException: Cannot run program "dir.exe": CreateProcess error=2, The system cannot find the file specified
Command [cmd, /c, dir] reported
Volume in drive D is Work Disk
Volume Serial Number is AC0B-0757
Directory of D:\dev\scratch
26/12/2008  22:15    <DIR>          .
26/12/2008  22:15    <DIR>          ..
03/09/2007  21:45    <DIR>          classes
26/08/2008  20:14            65,280 mynamedpipe
23/11/2008  11:37           201,354 name.ppt.txt
24/10/2008  20:00           201,354 race.txt
05/11/2008  23:17         6,193,334 record.csv
08/01/2009  16:44               704 scratch.iml
27/12/2008  12:29            21,576 scratch.ipr
08/05/2009  20:02            53,258 scratch.iws
28/04/2009  21:34    <DIR>          src
07/12/2008  11:44               101 test.txt
               8 File(s)      6,736,961 bytes
               4 Dir(s)  32,506,023,936 bytes free
Command [c:\cygwin\bin\dir] reported
classes      name.ppt.txt  record.csv     scratch.ipr  src
mynamedpipe  race.txt        scratch.iml     scratch.iws  test.txt