Regex to fetch particular string from an output

Question

While executing a below command in linux

root@11.222.33.38.11:~#  cat /etct/user.conf

I will get following data.

[General]
ui_language=US_en

From this i need to fetch the value of ui_language (US_en) only using regular expression.

you can do this using pattern and matcher class. – sandip bharadva Dec 07 '18 at 04:25 — sandip bharadva, Dec 07 '18 at 04:25
@divz Which programming language are you using to code? – Vishnudev Krishnadas Dec 07 '18 at 04:33 — Vishnudev Krishnadas, Dec 07 '18 at 04:33

jason120 · Accepted Answer · 2018-12-07T04:53:34.430

You can pipe to grep and sed:

cat foo.txt | grep 'ui_language=' | sed 's/ui_language=\(.*\)/\1/g'

Replace foo.txt with your file name.

Example:

host$ cat foo.txt 
[General]
ui_language=US_en
host$ cat foo.txt | grep 'ui_language=' | sed 's/ui_language=\(.*\)/\1/g'
US_en
host$

EDIT: I didn't realize you wanted to use java. This was not originally tagged with java. You can do that with the following:

MatchExample.java

import java.util.regex.*;
import java.io.File;
import java.nio.file.Files;

public class MatchExample {

    public static void main(String[] args) throws Exception {

        byte[] bytes = Files.readAllBytes((new File(args[0])).toPath());
        String s = new String(bytes,"UTF-8");

        Pattern pattern = Pattern.compile("ui_language=(.*)");
        Matcher matcher = pattern.matcher(s);
        if (matcher.find()){
            System.out.println(matcher.group(1));
        }
    }

}

This takes filename as the first parameter.

Compile:

host$ javac MatchExample.java

Run:

host$ java MatchExample foo.txt 
US_en
host$

score 0 · Answer 2 · answered Dec 07 '18 at 04:30

0

Pattern pattern = Pattern.compile("US_en");
Matcher matcher = pattern.matcher(mydata);
    if (matcher.find()){
        System.out.println(matcher.group(1));
    }

here,mydata is a string from which you want to fetch data

answered Dec 07 '18 at 04:30

sandip bharadva

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one thing is the value of ui_language= may varies..some times its value will be US_es or so one... – divz Dec 07 '18 at 04:33
store that string in one variable then pass that variable in pattern class compile method. – sandip bharadva Dec 07 '18 at 04:34
But we cant predict what langs are coming – divz Dec 07 '18 at 04:36

Regex to fetch particular string from an output

2 Answers2