Storing Shell Output

Question

I am trying to read the output of a shell command into a string buffer, the reading and adding the values is ok except for the fact that the added values are every second line in the shell output. for example, I have 10 rows od shell output and this code only stores the 1, 3, 5, 7, 9, row . Can anyone point out why i am not able to catch every row with this code ??? any suggestion or idea is welcomed :)

import java.io.*;

public class Linux {

    public static void main(String args[]) {


        try {
        StringBuffer s = new StringBuffer();

    Process p = Runtime.getRuntime().exec("cat /proc/cpuinfo");
    BufferedReader input =
            new BufferedReader(new InputStreamReader(p.getInputStream()));
    while (input.readLine() != null) {
        //System.out.println(line);
    s.append(input.readLine() + "\n");

    }
    System.out.println(s.toString());



} catch (Exception err) {
    err.printStackTrace();
}    }
}

Answer 1

Here is the code that I typically use with BufferedReader in situations like this:

StringBuilder s = new StringBuilder();
Process p = Runtime.getRuntime().exec("cat /proc/cpuinfo");
BufferedReader input =
    new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
//Here we first read the next line into the variable
//line and then check for the EOF condition, which
//is the return value of null
while((line = input.readLine()) != null){
    s.append(line);
    s.append('\n');
}

On an semi-related note, when your code does not need to be thread safe it is better to use StringBuilder instead of StringBuffer as StringBuffer is synchronized.