It's not often that I write about Perl Scripting on Unix Tutorial, but that's just because I don't script in Perl this much on a regular basis. Today, however, I'd like to share one of the building blocks – a really basic piece of functionality which you'll find really useful in almost any Perl script.
Archives for January 2009
List drives by UUID in Ubuntu
Having used this tip a few times myself, I'd like to share it with you: a very simple way to list all the drives in your Ubuntu system using their UUID's.
Updates in Unix Glossary
Just updated the Unix Glossary section with the following definitions:
There's no way these will be final, and so I'll be updating them now and them so stay tuned. For example, the Unix definition is still not in the glossary, because I'm struggling with wording the paragraph for it. Will add next week, for sure!
See Also
Unix Tutorial Digest – January 22nd, 2009
Now that I'm finally back into my usual posting and reading other blogs, I think it's a good time to restart the "Interesting Reads". Here are the Unix articles you might like:
* Tools to delete files securely in Ubuntu
* List installed packages in Ubuntu – some more tricks in addition to my original article
* Unmounting unresponsive CD/DVD drive in Linux Enjoy these useful Linux tips! If you have any useful articles you'd like to share – just leave links in the comments area.
New section added: Unix Glossary
I've just created another section on Unix Tutorial – the Unix Glossary, which is a section I'm going to use for listing definitions to all the topics I briefly touch in my regular posts.
So far, there's only one item there – runlevel definition. Obviously, it's a work in progress, so I'll be updating definitions constantly and expanding the section as I post more.
The plan is to have a Unix Glossary section at the bottom of each post on Unix Tutorial, so that it gives you another chance to expand your understanding of Unix basics.
If you have any terms from Unix world which you'd like me to cover first, please head over to the Unix Glossary page and leave a comment there with your suggestions.
Let me know what you think about this, do you think it will help? If there's any other side of this blog you'd like changed or improved – just let me know. I'm using this blog as my own reference all the time, so I always appreciate your feedback as it makes life easier and Unix Tutorial better for everyone.
Want to Learn Unix with me?
As I plan my goals for 2009, I'm thinking of making a few self-paced courses for all the readers of this blog.
I think it's about time some of the basics are covered in a format of a course, complete with structured material and examples and with some multiple-choices testing.
If you want to learn Unix
If you're interested in anything like this, please leave comments or contact me directly with your suggestions for course topics and desired structure. Also, if you're keen in becoming a member – join the Unix Tutorial waiting list right now!
Unix Tutorials – self-paced courses
So far, the most popular topics and therefore the first candidates for courses are the following:
- Unix shell scripting
- Finding files and directories in Unix
- Unix users and groups
- File ownership and access permissions
- rsync tutorial
- sudo tutotial
- unix sockets
- comparing files in Unix
Have you got an idea for a great Unix tutorial? Let me know and I'll see what I can do.
See also
Disable a startup of service in Ubuntu
If for whatever reason you stop using a certain service in your Ubuntu install and would like to disable automatic restarting for it upon system reboot, all it takes to do it is just one command line.
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How to see future file timestamps in Solaris
I know I've spoken about timestamps already, but I'd like to further expand the topic.
While there's a great GNU stat command in Linux systems, there's no such thing in Solaris by default, and so you usually depend on ls command with various options to look at file's creation, modification or access time.
The standard /bin/ls command in Solaris doesn't always show you the full timpestamp, usually if it's about a time too far in the past or a bit into the future – so today I'm going to show you a trick to work around it and still confirm such timestamps for any file.
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How To Check if Any Users Were Added or Deleted on Your Linux System
Yesterday in my post on numeric userids instead of usernames, I touched briefly the problem of recovering the username if you only know the userid it once had. Today I would like to show you another option which may be available to you when it comes to recovering the usernames of removed users by their userid.
[Read more…] about How To Check if Any Users Were Added or Deleted on Your Linux System
What to do if numeric id is shown instead of Unix username
As you know, every file in your Unix OS belongs to some user and some group. It is very easy to confirm the ownership of any file because user id and group id which own the file are always linked to the file. However, sometimes you can't tell which user owns the file, and today I'm going to explain why. It's a rather lengthy post and a complicated matter, so please leave questions or comments to help me polish this article off.
Files and directories ownership in Unix
If you look at any file using ls command, you will see an output like the one shown below – it reveals file access permissions, user and group id of the owner, the modification timestamp and the file name itself:
ubuntu$ ls -l /tmp/myfile -rw-r--r-- 1 greys admin 0 Jan 6 03:51 /tmp/myfile
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