Selective retrieval of numbers in a text file

shik28 · 11-23-2011, 02:25 AM

I have a text file as follows

Code:

             total       used       free     shared    buffers     cached
Mem:          7923       7875         47          0        564       3237
-/+ buffers/cache:       4074       3848
Swap:        12287       1067      11220
Total:       20211       8943      11267

I have to retrieve only those values which fall in the mem, swap and total under total, used and free i.e. I have to ignore 0, 564, 3237, 4074, 3848. How do I do it?

I have written the following code to display the all the numbers.

Code:

package my.scan;  
import java.util.*; //importing some java classes  
import java.lang.*;  
import java.io.*;  
  
class ReadFile {
	void getFile () {
		int i = 0;
		
	       try {  
	               Scanner myFile = new Scanner(new FileReader("C:/Documents and Settings/shikhau/workspace/SanNumber/freelast.txt"));  
	               while (myFile.hasNext()) {  
	                   if (myFile.hasNextInt()) {
	                	   i = myFile.nextInt();
	                	   System.out.println(i);
	                   }
	                   else {
	                   		myFile.next();
	                   }              
	               }  
	       }  
	       catch (FileNotFoundException e){  
	           System.out.println("Sorry! This file is not found");  
	       }
	}
}

public class ScanNum {  
    public static void main(String[] args) {  
        ReadFile rf = new ReadFile();
    	rf.getFile();
          
    }  
  
}

firstfire · 11-23-2011, 04:40 AM

Hi.
Well.. I know it is not what you are looking for, but here is how to do this in awk:

Code:

$ awk '$1~/Swap|Total/{print $2,$3,$4}' test.dat
12287 1067 11220
20211 8943 11267

where

Code:

$ cat test.dat 
             total       used       free     shared    buffers     cached
Mem:          7923       7875         47          0        564       3237
-/+ buffers/cache:       4074       3848
Swap:        12287       1067      11220
Total:       20211       8943      11267

Maybe this will give you idea how to implement this in java.