problems with exec("rundll32.exe shell32.dll...")

Tue May 20 14:39:00 GMT 2003

>However, we had a good reason for doing this:
>>http://gcc.gnu.org/ml/java-patches/2003-q1/msg00502.html
>>(Also see the messages following it).
>>I do not know why this behaviour changes for these
>programs - a simple test program in C that I wrote
>that merely prints out argv[] never manages to
>see the difference between quoted and unquoted
>command lines. :-(

hi Ranjit,
>The problem that you are reporting as well as that
>reported by Oywind can be traced to the fact that
>we put a double quote (") around every argument
>on a command line before calling Win32 CreateProcess( )

 I think this might not be the right thing to do?
Is the difference that
 exec(String s)
 parses s into an array of arguments using whitespace as the
delimiter* so
 cmd /C dir c:\program files
 would be parsed (correctly) to
{"cmd","/C","dir","c:\program","files"}, and then make the dir fail?
If the user in java wants to execute this they should do this:
 exec(new String [] {"cmd","/C","dir","c:\\program files"});
(demonstrated in code included below)
Once you have the String [], I think only the entries containing whitespace
need to be quoted - this should then bring the behaviour of the JRE + gcj
together.
thanks,
Andrew
======================================
*from the API
Executes the specified string command in a separate process.
 The command argument is parsed into tokens and then executed as a
 command in a separate process. The token parsing is done by a
 StringTokenizer created by the call:
 new StringTokenizer(command)
 with no further modifications of the character categories. This
 method has exactly the same effect as exec(command, null).
======================================
import java.io.*;
import java.util.*;
public class GCJTest2 {
 public static void main(String [] arg) throws Exception {
 System.out.println("Using String[] gives ");
 Process a = Runtime.getRuntime().exec(new String []
{"cmd","/C","dir","C:/Program Files"});
 new Thread(new Threader(a.getInputStream(),"(out)")).start();
 new Thread(new Threader(a.getErrorStream(),"(err)")).start();
 a.waitFor();
 System.out.println("String[] exit value: "+a.exitValue());
 System.out.println("\n\nUsing String gives ");
 Process b = Runtime.getRuntime().exec("cmd /C dir C:/Program Files");
 new Thread(new Threader(b.getInputStream(),"(out)")).start();
 new Thread(new Threader(b.getErrorStream(),"(err)")).start();
 b.waitFor();
 System.out.println("String exit value: "+b.exitValue());
 }
 static class Threader implements Runnable {
 BufferedReader br;
 String ss;
 Threader(InputStream is, String s) {
 ss=s;
 br = new BufferedReader(new InputStreamReader(is));
 }
 public void run() {
 try{
 for(String line; (line=br.readLine())!=null; ){
 System.out.println("\t "+ss+" "+line);
 }
 }catch(Exception e){e.printStackTrace();}
 }
 }
}