Re: exec() and sending to STDIO and reading from STDIO

From:

"crazzybugger" <ajaykumarns@gmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

20 Oct 2006 16:41:09 -0700

Message-ID:

<1161387669.806050.262040@b28g2000cwb.googlegroups.com>

WinstonSmith_101@hotmail.com wrote:

I have an external program I need to execute which takes an argument.
So I have the code:

String command = "...";
String argument = "...";
process = Runtime.getRuntime().exec(command);

And then for sending arguments:

java.io.OutputStream out = process.getOutputStream();
out.write(argument.getBytes());
out.close();

And the for reading output from the external command:

java.io.InputStream in = encryptProcess.getInputStream();
int c;
while ((c = in.read()) != -1)
{
System.out.print("OUT: " + (char)c);
}
in.close();

= = = = = = = = = = = = = = = = = =

But the problem is that the output is not actually read. It's still
being outputted when I close the InputStream (in.close();)

Is there not a way to but execute an external program, send arguments
to it and get it's output?

I have tried to insert the command "echo argument|command" e.g.
"echo test|ls" in the command, but this merely echos out the whole
line ("test|ls") rather than sending the argument "test" to
"ls".

Thanks
/Rune

I think you are doing a mistake here........If i am right you are
supposed to wait for the process to end .
      you can try out this sniplet.
try{
          Process p=Runtime.getRuntime().exec(yourCommand);
          int result=p.waitFor();
           if(result==0){

                /*this means that the program ran successfully.
                 *now use your buffered stream and read from the
process using the
                  *process.getInputStream() call*/

            }else{

           /*program did not run successfully!
            *use your stream and read from the process using the

            * process.getErrorStream()*/

           }
}catch(Exception e){
             /*you reach here incase the process did not execute
properly or wrong arguements */
}