Book Image

The Software Developer's Guide to Linux

By : David Cohen, Christian Sturm
5 (2)
Book Image

The Software Developer's Guide to Linux

5 (2)
By: David Cohen, Christian Sturm

Overview of this book

Developers are always looking to raise their game to the next level, yet most are completely lost when it comes to the Linux command line. This book is the bridge that will take you to the next level in your software development career. Most of the skills in the book can be immediately put to work to make you a more efficient developer. It’s written specifically for software engineers, not Linux system administrators, so each chapter will equip you with just enough theory to understand what you’re doing before diving into practical commands that you can use in your day-to-day work as a software developer. As you work through the book, you’ll quickly absorb the basics of how Linux works while you get comfortable moving around the command line. Once you’ve got the core skills, you’ll see how to apply them in different contexts that you’ll come across as a software developer: building and working with Docker images, automating boring build tasks with shell scripts, and troubleshooting issues in production environments. By the end of the book, you’ll be able to use Linux and the command line comfortably and apply your newfound skills in your day-to-day work to save time, troubleshoot issues, and be the command-line wizard that your team turns to.
Table of Contents (20 chapters)
18
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19
Index

Connecting Commands Together with Pipes ( | )

You’ve learned how to redirect each of the three standard file descriptors to various locations, and seen why that’s often useful. But what if, instead of just redirecting input and output to and from various files, you wanted to connect multiple programs together?

On the command line, you can use the pipe character (|) to connect together the output of one program to the input of another program. This is an extremely powerful paradigm that is heavily used in Unix and Linux to create custom sorting, filtering, and processing commands.

echo "some text \n treasure found \n some more text" | grep treasure

If you paste this into your shell, you’ll see treasure found printed out. Here’s what happened:

  1. The first command, echo, runs and produced the output you see between double quotes (the newline characters make this a 3-line string).
  2. The pipe character streams that output (file descriptor 1) to the input...