Exercises, examples and other material relating to training module A161. This topic is presented on public courses Deploying LAMP - Linux, Apache, MySQL, Perl/PHP, Linux Administration, Deploying Java Applications on Linux / Unix, Linux bootcamp

Linux is a true multiuser operating system. Each file and process is owned by a specific user and is accessible to others based on group and world permissions. In this module you'll learn how to create, monitor and secure user accounts and control user processes. You'll also learn about the all powerful root account and how to use it for such tasks as resetting regular user's passwords.

A Web interface for your Linux admin tasks

Articles and tips on this subject		updated
4045	Linux Web Server - User Roles, User Accounts, and shared administration There are many different roles associated with setting up and running a web site and it's unlikely that they'll all be undertaken by the same person. • Server administrator • Web site developer • Web site administrator • Web site user And each of them has their own areas of authority, ...	2013-03-31 (longer)
2639	su or su - ... what is the difference? If you're wanting to do admin work on a Unix or Linux system, you'll probably need to be logged in as the administrator. However, you're likely to find that you're not allowed to log in as root directly, and that you have to use the su command. Strictly speaking, "su" stands for "Substitute User" and ...	2010-03-03
2491	Root is root for a reason! A busy day ... major update to the Chamber of Commerce Site, and a heart-stopping moment when I realised that we had moved our server's clock forward by a year instead of by a few minutes. A few log files have some funny time stamps in them, and web stats will look odd for a while ... and there was ...	2009-11-03
2301	Mistaken identity? I asked who I was logged in as yesterday ... and I got two different answers: [melksham ~]# who am i trainee pts/1 2009-07-21 13:16 (192.168.200.80) [melksham ~]# whoami root [melksham ~]# When you log in to a Unix or a Linux box, you give an account name (and password, I hope!) and you're ...	2009-07-23
2203	Always use su with minus. And where do programs come from? When you're using the su command to do systems admin work as route, you should always add the - options (minus sign on its own) to start a new root environment too. This means that the PATH that executable files are found from is replaced (amongst other things) - so you can find things like ifconfig ...	2009-05-27
2117	Choosing a railway station fairly in PHP I've been transferring the West Wilts Rail Users Group web site into a wiki this evening ... and came up with the question "How do I fairly choose which station to put on their front page". Of course, I favour Melksham. It's far and away the one that needs all the help and support it can get from ...	2009-04-06
2103	Ask the Tutor - Open Source forum Well - I've taken the plunge! When I installed a YaBB forum some seven years ago, I never imagined that it would grow as big as it did, with hundreds of posts on each of the subjects covered. And with that growth came growth panes where the forum became "Pot Bound" - unable to grow any further. So, ...	2009-03-25
1902	sstrwxrwxrwx - Unix and Linux file permissions Have you ever wondered about those letters that turn up on the left of a long listing (ls -l) report? Here's an example: drwxrwxrwt   8 root    wheel    272 17 Nov  2007 Shared drwxr-xr-x  14 chris   ellis    476 29 Sep  2007 chrise drwxr-xr-x 270 graham  ellis   9180 23 Nov 07:25 grahame drwxr-xr-x  34 lisa    ellis   1156 27 Sep 06:44 lisae drwxr-xr-x  29 trainee trainee  986  5 Sep 03:55 trainee -rw-rw-r--   1 graham  ellis    294 23 Nov 07:41 uu -rw-r-----   1 graham  ellis    922 21 Nov 08:45 wb -rw-------   1 graham  ellis   5143 23 Nov 07:25 xx They're ...	2008-11-24
1904	Ruby, Perl, Linux, MySQL - some training notes We have just come to the end of a solid 12 days of training ... and we are just getting ready for the next week, with delegates arriving this evening. There's a lot going on behind the scenes, even over this weekend, with the hotel to be prepared as well as the training course. (Picture - our clean ...	2008-11-24 (longest)
1773	The Longest Possible Day I post here every day - or I try to at least. What is the longest possible gap between posts for me to leave, and still achieve that? Well - it's 48 hours and I'm very close to that today. Not that it's been quiet - in fact I had my head down yesterday, taking a whole lot of pages that we transferred ...	2008-08-27
1650	Looking for files with certain characteristics (Linux / Unix) I was about to use chown to change the ownership of an entire subdirectory tree that had been passed from one user to another. But - hang on - were there any files there that belonged to someone else for any reason? One way to find out - a find command: find . -not -user savethetrain -print "Find ...	2008-05-22 (short)
1619	User and Group settings for Apache httpd web server When you're running an Apache httpd web server, you should run it using a separate daemon user account and group set up for the purpose and not run it as either root (a horrific thing to do, as it would lead to all sorts of security holes) or nobody (another very bad idea, as the "nobody" applications ...	2008-04-23
1592	Setting up a new user - Linux or Unix Creating a local user account on a Linux box: 1. Add an entry to /etc/passwd 2. Add an entry to /etc/shadow 3. Add an entry to /etc/group IF the user is in a new group 4. Use the passwd command to set the user's password 5. Create the user's home directory 6. Change the ownership of the user's home ...	2008-03-27
409	Functions and commands with dangerous names There are some words that we use in our day to day programming life that seem a little scarey and inappropriate to their real task ... and sometimes those words worry trainees on our courses. Examples: PHP's reset function. It's name seems to threaten to clear our data from somewhere, but all it does ...	2006-06-05