For many text file compare and source file compare scenarios it is an essential requirement to ignore some of the differences. You may need to ignore line sequencing in a source file or dates or timestamps in a log file. Or maybe you want to ignore comments in a source file. These are just a few examples of when you’ll need a file compare tool with an option using Regular Expressions to identify a pattern to ignore. In addition to the pattern to ignore you will need to be able specify to ignore just that part of a line, or ignore the entire line. To ignore a block of lines you will need to be able to identify the pattern for the beginning of the block and another pattern for the end of the block.
But Regular Expressions can be difficult to understand for even the most seasoned veterans. Very few of us use Regular Expressions often enough to become an expert. Here’s a Tip: Do a search for Regular Expression Tester. You’ll find many good tools are available (most of them are online and free). These tools operate interactively and allow you to test your Regular Expression against a test text pattern.