December 2008
Intermediate to advanced
320 pages
6h 45m
English
Content preview from Expert Shell Scripting
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CHAPTER 9Data Redirection
Data redirection is when the input or output of a command is redirected using special notation. It is also used for opening and closing files for read and write operations. The forms and syntax of redirection are varied and their meanings are specific. I will cover some of the common uses here, and provide a bit more explanation than system man pages to aid you in avoiding pitfalls.
Avoiding Confusion
Data redirection is a common point of confusion among users. Problems with its usage arise most often when a user wants to set up a cron job that sends all its output to /dev/null, such as in the following crontab entry:
10 5 * * * /run/some/script > /dev/null 2>&1
In this example, all of the output will be sent to /dev/null ...
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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.