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

Introduction to logging

As we saw in the introduction, logs are simply informational messages – records of events happening in a software application or operating system. Like many Unix concepts, there are few hard and fast rules: if you write a two-line script that writes a timestamp into a text file, that might count as a log. Some logs are simple plaintext strings sent to well-known file locations on the system, and others are highly structured binary data managed exclusively by a daemon such as systemd.

As a developer, you’re probably familiar with log levels, which are labels that indicate the urgency of events on your software. Think “error,” “info,” and “debug” messages, which you’ve surely seen scrolling past in the terminal while developing software. We’ll cover these common log levels later, but for now, you should be aware of three main sources of logs in a modern, full-featured Linux environment...