Content preview from Learn Linux Shell Scripting - Fundamentals of Bash 4.4
- Why are flags often used as modifiers whereas positional parameters are used as targets?
Flags often modify the behavior: it can make a script more or less verbose, or perhaps write the output somewhere. Often, a command manipulates a file, which is then considered the primary target for what the command actually tries to achieve.
- Why do we run getopts in a while loop?
All flags are parsed sequentially, and when getopts can no longer find new flags it will return an exit code different from 0, which will exit the while loop at exactly the right moment.
- Why do we need a ?) in the case statement?We cannot trust the user to correctly use all flags all the time. ?) matches any flag we have not specified, which we can then use to inform ...
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.Mark W.
Publisher Resources
ISBN: 9781788995597