You should simply be able to run the jGrep Jar file distributed from http://www.DigitalGemstones.com without any trouble. However if you download the source code, or have any difficulty with the JAR, you can follow the below instructions to build and run jGrep.
Building this program from the command line, you can call
$ javac grep/*.java $ java grep.JGrep
src directory of the repository.
If you have trouble with jGrep, you can contact me at http://www.digitalgemstones.com/contact.php Please include the operating system and version of Java you are running, along with any other details you can, especially including stack traces, and a description of what you did to cause the error.
Copyright 2010 Michael Diamond - http://www.DigitalGemstones.com
This file is part of jGrep.
jGrep is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
jGrep is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with jGrep. If not, see http://www.gnu.org/licenses/.