Extracting a number that occurs after a specific word from a longer text/file

Question

I have a text file of 5631 lines. I want to extract and store the number which appears after the word bytes at

Sample line form middle of the file is below :

debug3: In write loop, ack for 1606 32768 bytes at 52527104

Here I want the value 52527104. Each line this value increases and my goal is to calculate the percent completion based on each lines value. By using the formula ((obtained*100)/total).

Thanks.

In this specific case you can just do `String[] splits = string.split(" ");` and to access it, `splits[splits.length-1];`. — eric.m, Sep 11 '15 at 10:19
Are you forced to use java? There are a number of unix command line tools that would be far better for this specific case — Diego Martinoia, Sep 11 '15 at 10:24
As I am beginner to unix it could be a mess. But any help will be highly appreciated. @DiegoMartinoia — S. Das, Sep 11 '15 at 10:38

YoungHobbit · Accepted Answer · 2015-09-11T12:25:30.977

2

You can simply split the read lines by bytes at and use the value at index 1. I have used Long parser, you can use Integer as per your requirement. The code will ignore lines, which doesn't contain the pattern provided.

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class BytesAt {
  public static void main(String[] args) throws FileNotFoundException {
    Scanner read = new Scanner(new File("input.txt"));
    while (read.hasNextLine()) {
      String line = read.nextLine();
      String parts[] = line.split("bytes at");
      if(parts.length > 1) {
        System.out.println("Value as String: " + parts[1].trim());
        System.out.println("Value as Long: " + Long.parseLong(parts[1].trim()));
      }
    }
  }
}

edited Sep 11 '15 at 12:25

answered Sep 11 '15 at 10:22

YoungHobbit

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1

@Keppil Thanks. I missed it. – YoungHobbit Sep 11 '15 at 10:31
@s-das updated with a conditional check, to handle other lines of the file which doesn't contain pattern. – YoungHobbit Sep 11 '15 at 10:43
1

This answer is correct only if `bytes at %NUMBER%` appears at the end of the line.`read.hasNextLine()` is more suitable. – akash Sep 11 '15 at 12:19
@TAsk Thanks. Updated it. – YoungHobbit Sep 11 '15 at 12:26

score 0 · Answer 2 · answered Sep 11 '15 at 11:06

How about:

long totalBytes = //Whatever source.
long currValue = 0;
for (String line: lines) {
  if (line.contains("bytes at")) {
    long currValue = Long.parseLong(line.split("bytes at\\s")[1]);
  }
  System.out.println("Completed % = "+(float)(currValue/totalBytes*100);
}

Extracting a number that occurs after a specific word from a longer text/file

2 Answers2