Sending Multiple Inputs to a Command with exec

Question

I need to execute a command at the command line and a series of Yes or No answers need to be provided after the command is executed. For example:

>./somecommand (return)

Are you sure about this? [yes/no]: yes (return)

Are you really sure about this? [yes/no]: yes (return)

Last chance. [yes/no]: no (return)

OK.

I'm trying to use the following code snippet to accomplish this task.

try {
   // Execute command
   String command = "somecommand";
   Process child = Runtime.getRuntime().exec(command);

   // Get output stream to write from it
   OutputStream out = child.getOutputStream();

   out.write("yes".getBytes());

   out.flush();      
   out = child.getOutputStream();
   out.write( "yes".getBytes() );

   out.flush();      
   out = child.getOutputStream();
   out.write( "no".getBytes() );

   out.close();
} catch (IOException e) {
}

As you can see, I tried using 'out = child.getOutputStream()' three times, flushing 'out' after each write. But that didn't seem to work. Any idea how this could be done?

check the following post: http://stackoverflow.com/questions/2877609/in-java-send-commands-to-another-command-line-program — , Sep 01 '11 at 17:22
Does `somecommand` have an `--assume-yes` or similar option? — trashgod, Sep 01 '11 at 18:52
No .. I need to capture the question the process outputs and based on that provide an answer to the question. — Mohammad Najar, Sep 01 '11 at 19:20

score 1 · Accepted Answer · answered Dec 26 '14 at 17:17

1

Try the java readLine() command in a while loop. Give it a terminating condition like Yes or No.

answered Dec 26 '14 at 17:17

Mike Vince

26
4

Sending Multiple Inputs to a Command with exec

1 Answers1