December 2025
Intermediate to advanced
704 pages
15h 22m
English
Content preview from Linux Command Line and Shell Scripting Bible, 5th Edition
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapter 25The Korn Shell
To wrap up the discussion on alternative Linux shells, this chapter takes a look at the Korn shell. While the Korn shell is popular in the UNIX world, it hasn’t gained much attention in the Linux world. The Korn shell offers an interesting mix of features from both the Bourne and C shells. This chapter discusses the features of the Korn shell and walks you through the most common version of the Korn shell in Linux, the ksh93 shell.
The Korn Shell History
The original Korn shell (called ksh) was developed by David Korn while working at AT&T Bell Labs in the 1980s. David developed the Korn shell (you can probably guess where its name comes from) to be a next-generation programming shell, incorporating the best features of the Bourne and C shells, as well as adding some more advanced support for scripting. The Korn shell quickly became known as a programmer’s shell. It supports advanced programming features missing from both the Bourne and C shells, including associative arrays and floating-point arithmetic.
The original Korn shell was controlled by AT&T as a proprietary shell up until 2000. Since then, it has been released as an open source software project.
There are two separate threads of the original Korn shell:
- ksh88
- ksh93
Most Korn shell implementations (including those found in Linux distributions) ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.