December 2008
Intermediate to advanced
320 pages
6h 45m
English
Content preview from Expert Shell Scripting
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CHAPTER 12cron
The system scheduler on UNIX and Linux systems is called cron. Its purpose is to run commands, series of commands, or scripts on a predetermined schedule. Normally these tasks are performed on systems that run 24 hours a day, 7 days a week. Writing cron scripts to perform system maintenance, backups, monitors, or any other job that you would want to run on a schedule is a very common task. There are a few subtleties with cron however, that many users and administrators may be unaware of.
crontab Entries
On a UNIX or Linux system, the cron daemon process runs all the time. A daemon is generally a program that runs as a background task and provides some type of service, in this case a scheduler. A run control (rc) script starts ...
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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.
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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.