readline

How to prompt users for input from Scala shell scripts

This is an excerpt from the Scala Cookbook, partially modified for the internet. This is Recipe 14.12, “How to prompt users for input from Scala shell scripts.”

Back to top

Problem

You want to prompt a user for input from a Scala shell script and read her responses.

Back to top

Solution

Use the readLine, print, printf, and Console.read* methods to read user input, as demonstrated in the following script. Comments in the script describe each method:

Table of Contents

  1. Problem
  2. Solution
Back to top

Scala shell scripts and the command line: Prompting the user, and reading input

A great thing about Scala is that not only is it scalable, it was also created to help you work on small tasks, including being useful in shell scripts. This includes small shell script tasks like prompting a user interactively from a shell script, and reading their input.

You can prompt users with print commands like println and print, and you can read their input with all of these methods that are available on the Scala Console class:

Java BufferedReader examples

Java file FAQ: Can you share some examples of the Java BufferedReader class?

When it comes to reading character input streams, the Java BufferedReader class is extremely important, and I'll demonstrate this in several different source code examples.

Java file open, read, and write utilities

Java file utilities FAQ: Do you have any Java file utilities you can share?

As I was working on another Java/Swing application this weekend, I ran across my "Java file utilities" class, and I thought I'd share that class here today. It's nothing too major, but it does include Java methods that let you open, read, write, and copy files using Java.

How to open a file and read its contents using Ruby

Ruby file FAQ: How do I open and read from a file in Ruby?

How many ways are there to open a file with Ruby and process the file contents? I don't know for sure, but here are two different ways to do it.

Ruby file processing, version 1

First, I'll use Ruby and the File.open method to open a file and process its contents, like this: