Unix Tutorial

You are here: Home / Archives for 2008

Archives for 2008

How To Create User Accounts in Unix

by 13 Comments

If you want to quickly create a new user account in your Unix OS, it ca be done with just one line

Adding new user accounts in Unix

To create a basic Unix user account with default settings, you need to know only one thing: the username.

The reason I say it as one word is because username (quite often referred to as "login") is not the actual name of the new person gaining access to your Unix system, but rather a single keyword uniquely identifying this user in your system. Most often, usernames are derived from real names of users – jsmith, johns or smithj for John Smith, just to give you a few examples.

The simplest way to add a new user to your system is to do run a command like this:

ubuntu# useradd jsmith

[Read more…] about How To Create User Accounts in Unix

New section on this blog: Unix Commands

by Leave a Comment

I've just integrated a new section: Unix Commands. The long-term plan is to have a categorized list of commands with most common usage documented in my typical easy-to-follow examples.

So far, there's not much, but I will referer to this section a lot in my future posts and its pages will have more examples for a particular Unix command compared to the original Unix Tutorial post where such a command is mentioned.

Have a look for yourself:

  • Unix Commands – the main index
  • Basic Unix commands – like it says, they really are basic. If you can think of something else which should be part of it, let me know
  • Advanced Unix commands – to Unix gurus they'll seem basic as well, but my only guidance so far was that commands there will be the ones you don't have to use on a daily basis. As I add more pages, this section will most likely become something like "Most common Unix commands" and a set of really advanced commands will be added.

Let me know what you all think, and if there are some immediate candidates for any of the section – let me know and I'll add them to my list!

Confirm the Day of the Week Based on a Timestamp

by 1 Comment

I recently created a Unix Questions and Answers page, if you have a Unix question – feel free to ask it there using the submit form and I'll do my best to help you out.

Today's Unix question is this:

How can we write a shell script in unix to find the day of the week when date is given?

The solution for this is even simpler: there's no need for Unix scripting, all you need is to have GNU date command at your disposal. I've already shown you all the basic date/time calculations using this great tool, and that's just another way of using it.

How to find a Day of the week based on timestamp

All you need is to know the base date. Let's say I'm interested in October 16th, 2009. Here's how easy it is to confirm that day will be Friday:

ubuntu$ date -d "Oct 16 2009" "+%a"
Fri

That's it – enjoy!

See also:

How To Update atime and mtime for a File in Unix

by 3 Comments

If you remember, all files and directories in Unix filesystems have three timestamps associated with them – atime, ctime and mtime. Since questions about modifying access time (atime) and modification time (mtime) are quite frequent in my website logs, I thought I'd explain how it is done.

How to view atime, ctime and mtime

Before we go any further, I'd like to remind you that using stat command is probably the easiest way to look at all the three timestamps associated with each file:

[Read more…] about How To Update atime and mtime for a File in Unix