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

The systemd journal

When a system uses systemd, journald takes over the logging side. When you’re troubleshooting a Linux machine running systemd, this is the first place you should be looking for logs. By default, journald captures all output from supervised processes. Anything emitted on stderr is treated as an error. So, unless the software is configured or hardcoded to log to a location that’s not stderr/stdout, you will find the logs in the systemd journal.

Logs logged to journald can be queried via the journalctl command. It provides a means to query based on individual services, time, and system restarts and allows one to use options similar to the tail command. Let’s jump in and get some practice using journalctl.