Posted in Unix, scripting

Unix and friends

UNIX

Knowing Unix command line is definitely not something that you’ll impress a nice girl, but it might be something that you’ll impress cute geek guy 😉

What is Unix

As I wrote before  Unix is a family of multitasking, multi user computer operating systems. I was told that my definition was not precise enough, so for those of you, who are completely not familiar with Unix, I’ll repeat:

Unix is a OS (Operation System).

It is not a tool.

It consists of large number of tools.

It’s like a mother-ship for other OSes (such as Linux or you’re favorite Mac 😉 ).

In order to talk to Unix – you’ll need to be using the command line.

(I hope this time it was explicit enough :)).

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Moving on

In Unix-like systems the commands are quite often nothing else but tiny programs, which run from command line. They are form of shells. Most of the shells can be also used as scripting language, which enables the user to perform multiple tasks and write scripts to automate repetitive activities.

There is several scripting languages available (csh, ksh, bash). As far as I know, one of the most popular in Unix is bash.

Before you start a little chit chat with your console – it is good to know the basics – and what I mean by that is to read about FHS – Filesystem Hierarchy Standars. Unless you won’t be a smart-ass.

FHS is common for Linux and Unix systems.

Examples

Having said that, let’s move on to the most useful commands that allow you talk to Unix.

One of the cutest commands I’ve ever seen is whoami. It is a real command. It doesn’t mean that Unix would reveal the secrets of life in front of you, but after several hours of coding it is good to know your name, right?

What might be more useful in real life? What do I use on daily basis?

bash  – switch scripting language to bash

pwd – show current directory

cat   – show file content

cd    – change directory

/       – hint – in Unix (in a contrary to Windows console) we use / instead of \

cp  – copy

ls   – list

ls -l   – list with rights – this command shows hidden rights to the files inside current catalog

 -a   – list hidden files

ln  – create hard link

rm – remove file or catalog

chmod  – adding/removing rights to the files

-al      – show hidden catalogs

history – this one fellow might be useful at the beginning – it lists all previous commands

Please try it at home. Next time we’ll play a bit more with Unix. I’ll show you some tricks.

As usual, stalk me on Twitter – all of your comments are very welcome.

Cheers!

Posted in databases, Unix

Introduction to Unix

One day this unexpected situation comes.

This is Linux.

This is your console.

We use Unix.

Enjoy.

introduction

It wasn’t that bad:) Fortunately, I’ve received a good companion to get familiar with Unix and not to drown. Let’s get to the point.

What is Unix

miniux

For those, who use Windows on daily basis it might be surprising. Sure we are aware that there is something more out there (like Mac 🙂 ) but Unix? Linux, Unix, they are operation systems just like your beloved Windows 🙂

Traditionally, let’s start from Wikipedia’s definition:

Unix is a family of multitasking, multi user computer operating systems that derive from the original AT&T Unix, developed starting in the 1970s.

You may be familiar with Linux, Unix is a bit similar. They have common source and behave in a similar manner.

Linux is a pure Kernel – Unix consists of Kernel and some additional software. Linux is free – Unix – in most cases – is not 😦 What is more, Linux, originated from a programmer’s toy – became a powerful tool for large machines. Unix though, starting from exclusive , expensive environments, nowadays is used on small PCs.

What you have to know – there are different types of Unixes. They are comparable, but not exactly the same. To talk to Unix you need to get familiar with any shell.

Why do we need them anyway?

We need Unix in order to work on remote desktops – or – to enable multiple users to use one space. What is more – each Linux/Unix enthusiast would tell you that it’s reliable. They won’t prompt you seven times if you REALLY REALLY wanna delete this file, but at the same time, they won’t run an update in the middle of conversation 🙂

Unix is a common “tool” used by large companies. It is very useful in working with databases.

You have to make some effort to get familiar with console and simple script languages, but if I was manage to do so – you’ll be able to to that for sure:)

In my next posts I would go a bit deeper into subject and move on with simple commands, that are useful for me in testing activities and managing files.

Here you can find more complex information about what Unix is.

As always – I recommend you to install it by your own and just play around. You could also get familiar with Unix with this simple course from Codeschool here (no, the don’t pay me, they just have awesome courses) .

Stalk me on Twitter. Enjoy. 🙂