Over the next few posts I’ll be covering three basic elements of files in Linux: Permissions ACL’s (Access Control Lists) File Attributes The ls command Every file in Linux has three primary permissions settings (read, write, execute) that apply to three elements (owner, group, others). File permissions can be viewed on the command line using the ls command. [luke@testserver stuff]$ ls -l total 0 -rwxrw-r-x 1 luke admins 0 Jun 21 19:44 file1 Looking at the output from ls -l , from left to right we can break the output into several groups as shown below.
Being a big proponent of Linux on the desktop I was excited to have the opportunity to talk with Aaron Prisk of the West Branch Area School District, who has recently helped migrate 80% of the school district’s infrastructure to Linux. When I first heard about the district’s move to Linux I wanted to find out as much as I could about his experiences during and after the migration. This is a great story about how Linux can be used by people of all ages and technical skill while still providing a low cost and secure platform for everyday operations.
Using search and replace is a great way to save time when editing large files in Linux. Becoming proficient with this task will increase your efficiency and will reduce your time spent doing tedious and error-prone file edits by hand. For the sake of this tutorial, I’m going to use a copy of the /etc/apt/sources.list file to illustrate some of the changes that we can make. From your users home directory copy the sources.
So you’re running through some instructions to configure software on your system, or troubleshoot some problem with a service and you see an error at the command line that says “command not found”. Here is how to locate the packages you need to install in order to use commands that are not available on your system. CentOS/Red Hat - yum provides Yum is an excellent package manager with lots of great built in functions.
You may occasionally come across an issue where running df will produce output that disagree’s with the output of the du command. If you aren’t familiar with these two commands do see my post about filesystem and directory size. The reason for the difference in reported size is that df does not differentiate between files that are open in memory but have been deleted, or altered on the disk, whereas du will only see the files that are on the disk.
Suse Enterprise Linux and it’s upstream community distro openSUSE use a package manager called zypper . zypper is a fast easy to use package management tool. In my opinion, zypper is hands down the best package manager out there. It provides meaningful, easy to read output, it resolves package dependencies quickly, and it has a cool name. zypper has many options that can be abbreviated; install (in) , search (se) , info (if) , update (up) and lots of others.