June 2006
Intermediate to advanced
64 pages
2h 42m
English
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Name
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Synopsis
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Null command. Returns an exit status of 0. See this Example and the ones under case. The line is still processed for side effects, such as variable and command substitutions, or I/O redirection.
Example
Check whether someone is logged in:
if who | grep $1 > /dev/null then : # Do nothing if user is found else echo "User $1 is not logged in" fi
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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.