Create a command-line filter utility

The Console class exposes two properties that make it very simple to create command-line utilities that work as filters, exactly like the FIND and MORE utilities that are provided with the operating system. The Console.In property returns a TextReader object that reads from the standard input channel, and Console.Out returns a TextWriter object that writes to the standard output channel. See how you can use these properties to create a simple filter utility that transforms all the incoming text to uppercase:

Module Module1    Sub Main()        ' Read from the standard input channel until there are characters.        Do While Console.In.Peek <> -1            Dim text As String = Console.In.ReadLine            Console.Out.WriteLine(text.ToUpper)        Loop    End SubEnd Module

Compile the application to Upper.exe and use it as a filter from the command line in this way:

TYPE myfile.txt | UPPER > uppercase.txt


UPPER < myfile.txt > uppercase.txt

In both cases the uppercase.txt file will contain the same contents of myfile.txt but converted to uppercase.

If you need to notify errors to the console window you can use the TextWriter object returned by the Console.Error property, which is never redirected to a file:

Console.Error.WriteLine("Syntax Error")

Share the Post:
Share on facebook
Share on twitter
Share on linkedin


The Latest

your company's audio

4 Areas of Your Company Where Your Audio Really Matters

Your company probably relies on audio more than you realize. Whether you’re creating a spoken text message to a colleague or giving a speech, you want your audio to shine. Otherwise, you could cause avoidable friction points and potentially hurt your brand reputation. For example, let’s say you create a

chrome os developer mode

How to Turn on Chrome OS Developer Mode

Google’s Chrome OS is a popular operating system that is widely used on Chromebooks and other devices. While it is designed to be simple and user-friendly, there are times when users may want to access additional features and functionality. One way to do this is by turning on Chrome OS

homes in the real estate industry

Exploring the Latest Tech Trends Impacting the Real Estate Industry

The real estate industry is changing thanks to the newest technological advancements. These new developments — from blockchain and AI to virtual reality and 3D printing — are poised to change how we buy and sell homes. Real estate brokers, buyers, sellers, wholesale real estate professionals, fix and flippers, and beyond may