The chmod Command
Chmod also provides a few command line options to simplify administrative tasks. For changing file permissions in directory trees use -R.
$ chmod -R g-w test_dir
This would remove write permission for group for all of the files in and below test_dir.
In order to control the output of messages from chmod use -c, -v and -f:
$ chmod -v 700 test_file mode of test_file changed to 0700 (rwx------)
This option caused chmod to display how the permissions of test_file were set. The -c option causes chmod to display messages only when files are changed, and the -f option suppresses messages about files that can't be changed.
Chmod also provides a --version option to display the version and --help to see a short help message.
File permissions are an integral part of Linux. The same concepts also apply to other operating system objects such as semaphores, shared memory, and NIS+. This tutorial provides you with some of the basic knowledge necessary to protect your data and have more fun with your Linux system, and provides you with mental building blocks for learning more about Linux.
Eric Goebelbecker (firstname.lastname@example.org) is a systems analyst for Reuters America, Inc. He supports clients (mostly financial institutions) who use market data retrieval and manipulation APIs in trading rooms and back office operations. In his spare time (about 15 minutes a week...), he reads about philosophy and hacks around with Linux.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
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With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide