Mastering The Linux Shell : Standard In, Out, and Error

Welcome to part four in my Mastering The Linux Shell series where we will wander wistfully into a land where three terribly under-appreciated but vitally important files live. You will remember that everything is a file, including directories which some people call folders. What you may not know is that your keyboard is a file, as is the screen on which you read these words. And if all hell breaks loose, all that goes into a file too. Those special files, and variations on those files, are always in use, unlike those other, less hard-working files that seem to get all the credit. They are called STDIN, STDOUT, and STDERR.