Is there a Pattern Matching Utility like GREP in Windows?

Question

Is there a similar utility to grep available from the Windows Command Prompt, or is there a third party tool for it?

Answer 1

I know that it's a bit old topic but, here is another thing you can do. I work on a developer VM with no internet access and quite limited free disk space, so I made use of the java installed on it.

Compile small java program that prints regex matches to the console. Put the jar somewhere on your system, create a batch to execute it and add the folder to your PATH variable:

JGrep.java:

package com.jgrep;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class JGrep {

    public static void main(String[] args) throws FileNotFoundException, IOException {
        int printGroup = -1;
        if (args.length < 2) {
            System.out.println("Invalid arguments. Usage:");
            System.out.println("jgrep [...-MODIFIERS] [PATTERN] [FILENAME]");
            System.out.println("Available modifiers:");
            System.out.println(" -printGroup            - will print the given group only instead of the whole match. Eg: -printGroup=1");
            System.out.println("Current arguments:");
            for (int i = 0; i < args.length; i++) {
                System.out.println("args[" + i + "]=" + args[i]);
            }
            return;
        }
        Pattern pattern = null;
        String filename = args[args.length - 1];
        String patternArg = args[args.length - 2];        
        pattern = Pattern.compile(patternArg);

        int argCount = 2;
        while (args.length - argCount - 1 >= 0) {
            String arg = args[args.length - argCount - 1];
            argCount++;
            if (arg.startsWith("-printGroup=")) {
                printGroup = Integer.parseInt(arg.substring("-printGroup=".length()));
            }
        }
        StringBuilder sb = new StringBuilder();
        try (BufferedReader br = new BufferedReader(new FileReader(filename))) {
            sb = new StringBuilder();
            String line = br.readLine();

            while (line != null) {
                sb.append(line);
                sb.append(System.lineSeparator());
                line = br.readLine();
            }
        }
        Matcher matcher = pattern.matcher(sb.toString());
        int matchesCount = 0;
        while (matcher.find()) {
            if (printGroup > 0) {
                System.out.println(matcher.group(printGroup));
            } else {
                System.out.println(matcher.group());
            }
            matchesCount++;
        }
        System.out.println("----------------------------------------");
        System.out.println("File: " + filename);
        System.out.println("Pattern: " + pattern.pattern());
        System.out.println("PrintGroup: " + printGroup);
        System.out.println("Matches: " + matchesCount);
    }
}

c:\jgrep\jgrep.bat (together with jgrep.jar):

@echo off
java -cp c:\jgrep\jgrep.jar com.jgrep.JGrep %*

and add c:\jgrep in the end of the PATH environment variable.

Now simply call jgrep "expression" file.txt from anywhere.

I needed to print some specific groups from my expression so I added a modifier and call it like jgrep -printGroup=1 "expression" file.txt.