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
Other Books You May Enjoy
19
Index

Practical Pipe Patterns

As mentioned before, longer multi-pipe commands are built iteratively – one command at a time. However, there are some useful patterns that you’ll see re-used frequently.

“Top X”, with count

This pattern sorts the input by number of occurrences, descending. You saw this in the original example from this chapter, which displayed the most frequently used shell commands from Bash’s history file.

Here’s the pattern:

some_input | sort | uniq -c | sort -rn | head -n 3
  • The input is sorted alphabetically, and then run through uniq -c, which needs sorted input to work on.
  • uniq -c eliminates duplicates, but adds a count (-c) of how many duplicates it found for each entry.
  • sort is run again, this time as a reverse-numeric (-r and -n) sort which sorts the unique counts from the input and outputs the lines in reverse (highest number first) sorted order.
  • head takes that top ranking and cuts it down to three lines (-n 3), giving you...