June 2006
Intermediate to advanced
64 pages
2h 42m
English
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Name
!
Synopsis
! pipelineNegate the sense of a pipeline. Returns an exit status of 0 if
the pipeline exited nonzero, and an exit status of 1 if the pipeline
exited zero. Typically used in if
and while statements.
Example
This code prints a message if user jane is not logged on:
if ! who | grep jane > /dev/null
then
echo jane is not currently logged on
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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.