OSA B7

B7 :Write Java script to display all logged in users. Count the number of logged-in users. Write a program to create a foreground and background process for the selected user and display its status.

Program:

import java.io.BufferedReader;

            import java.io.InputStreamReader;

            public class assign7

            {

            public static void main(String[] args){

            int count=0;

            try{

            String line,line1;

            Process p=Runtime.getRuntime().exec("who");

                                    //getRuntime().exec("who");

            BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));

            while((line=input.readLine())!=null)

            {

            System.out.println(line);

            count++;

            }

            System.out.println("No.of users are:"+count);

            input.close();

            Process q=Runtime.getRuntime().exec("ps");

            BufferedReader input1 = new BufferedReader(new InputStreamReader(q.getInputStream()));

            while((line1=input1.readLine())!=null)

            {

            System.out.println(line1);

            //count++;

            }

            //System.out.println("No.of users are:"+count);

            input.close();

            }

            catch(Exception e)

            {

            e.printStackTrace();

            }

            }

            }

Output:

  [student@localhost ~]$ javac assign7.java

[student@localhost ~]$ java assign7

student  :0           2013-10-09 08:29 (:0)

student  pts/0        2013-10-09 11:57 (:0)

No.of users are:2

  PID TTY          TIME CMD

 5413 pts/0    00:00:00 bash

 5733 pts/0    00:00:00 java

 5747 pts/0    00:00:00 ps