File IO in Every Language

Welcome to the start of another Sample Programs in Every Language series! Today, we’re kicking off File IO in Every Language, a series about file interaction.

Table of Contents

What is File IO?

For those who aren’t aware, IO is short for Input/Output. Append “File” to the front of that string to get a concept known as File IO: the basis of file reading and writing. In this series, we define File IO as any program which writes to a file and reads from that same file.

In particular, languages in this series should be able to write some arbitrary text to a file called output.txt, read that text back, and present it to the user. For example, let’s say the following text is what we want to write to a file:

This is a line of text.

And, this is another line of text.

Then, a File IO in Every Language program should write this text to output.txt, read the text back, and display it to the user like:

./file-io-program
This is a line of text.
And, this is another line of text.

To verify that the program worked, check that a file called output.txt has been created, and that it contains the text above. That’s it!

Why File IO in Every Language?

To be honest, I didn’t come up with this idea. One of our biggest contributors, Noah, did. As a result, I have them to thank for this awesome series. In fact, many of the programs in this series were implemented by Noah, so give them a shout out in the comments.

That said, File IO can be a very important part of any system. In fact, I do a bit of File IO for this site. Every image you see on The Renegade Coder was generated by a Python program that uses file IO to read images and create new ones.

In general, File IO can be useful in all sorts of automation. I’m sure a lot of people have written little scripts to eliminate some busy work from their jobs. I’ve done that. Why update a file every day when you can automatically update it with scripting?

My point is File IO is important, and I think it makes a great addition to the Sample Programs in Every Language series.

An Alphabetical List of Languages

As usual, here’s a list of articles organized alphabetically:

1. File IO in C++
2. File IO in Python
3. File IO in Ruby

Once again, thanks for sticking around. If you’re enjoying this site, consider becoming a member. At least that way, you’ll be able to share your recommendations in the comments. At any rates, until next time!