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

Example journalctl commands

The basics of working with journalctl are simple. Think about it; when you’re troubleshooting an application, what do you need to be able to do with its logs?

First, you’ll want to be able to find and view the current set of logs. journalctl will give you that, but you’ll quickly realize you didn’t actually want all the logs, just the most recent ones. So, let’s filter with the -n flag.

To get a look at the last 100 log messages in journald, try this command:

journalctl –n 100

This will print out the last 100 lines logged to the system. You will notice that this is similar to the tail command explained earlier in this book. If you followed along, these lines will likely contain the “Hello World!” message from above.

Following active logs for a unit

You might also want to see logs in real time. For example, following your application logs during startup can help you see exactly...