UNIX Basics and Shell Scripting
UNIX is a multitasking, multi-user computer operating system that exists in many variants. UNIX is the oldest and most secure operating system architecture present today. Linux/Unix is still used today in a lot of servers. Almost 80% of the websites are running on UNIX servers.
what is Shell and why shell?
Every woodworker needs a good, solid, reliable workbench, somewhere to hold work pieces at a convenient height while he or she works them. The workbench becomes the centre of the wood shop, the craftsman returning to it time and time again as a piece takes shape. similarly for any software engineer(Programmer/Tester/Support Eng) manipulating files of text, programs and for automation , that workbench is the command shell .
Who should do shell?
Almost all the Software engineer should learn shell
Shell Scripting Introduction
Unix uses shells to accept commands given by the user, there are quite a few different shells available. The most commonly used shells are SH(Bourne SHell) CSH(C SHell) and KSH(Korn SHell), most of the other shells you encounter will be variants of these shells and will share the same syntax, KSH is based on SH and so is BASH(Bourne again shell). TCSH(Extended C SHell) is based on CSH.
The various shells all have built in functions which allow for the creation of shell scripts, that is, the stringing together of shell commands and constructs to automate what can be automated in order to make life easier for the user.
For whom UNIX/LINUX is?
In short for everyone, doesn’t matter if you are a developer, manual tester, support professional or Manager, if you are in the IT industry UNIX is must for you!
Why more than 90% of company software’s, web servers run on UNIX OS?
UNIX is the oldest and most secure operating system present today. UNIX architecture is definitely more robust, secure and reliable than that of Windows, All Linux distributions, Free BSD, HP-UX by HP, AIX by IBM, Solaris by Oracle, and Mac OSX by Apple are purely UNIX based operating systems.
Why UNIX is useful (in Trainer words)?
UNIX knowledge is very useful for any IT professionals. People spend lot of time on working on some specific task in
Microsoft environment it can be done in a few seconds by using existing UNIX commands, utility or writing a 4 lines of shell script.
UNIX knowledge is necessary. In many fields of the IT business, critical stuff, servers, applications relies on UNIX systems. Many servers/super-computers/appliances/devices/etc have a UNIX core.
UNIX knowledge is not hard. This is by design. That doesn’t mean everyone can be a UNIX guru in a couple weeks, far from that. But all, and by that I mean all, the information you need is available.
UNIX knowledge is efficient. Replacing a 5K LoC application with 3 piped commands, and improving the performances at the same time is always nice.
UNIX knowledge is fun. It’s actually hard to tell you why, but it sure is … in a geeky way. 🙂
