Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/a26f9f83/public_html/articles/includes/config.php on line 159
Intro to UNIX Shells > NetSparsh - Viral Content you Love & Share

Intro to UNIX Shells

A UNIX Shell is in simplest terms, a command line interpreter, that takes the users input and gives it to the Kernel. If you are familiar with DOS, you will remember the 'command.com' that file takes the users information and passes it to the operating system in a way it can be understood by the system. With DOS you only had one type of shell, but with UNIX you have a variety, each with their own abilities, pluses and minuses.

Keep in mind as you read about these shells, that though they may have major differences when they were created, that they have been updated and many features that were once only available in a single shell, may be available in other shells. This is more of a history lesson.

'sh'
The Bourne shell, named after its creator Steve Bourne is the oldest shell for most major distributions of UNIX and LINUX. Most shells today are in some fashion derived from the Bourne shell.

'csh'
The C Shell. The C shell is a great shell that has many advantages over the original Bourne shell, it was the first to introduce a history (the ability to scroll up, to view past commands). Also the C Shell as the name implies also integrates a great portion of the C programming language. If you are able to program in C, you can pretty much do it all in a shell script or from the command line, if you so desired.

'ksh'
The Korn Shell. Named after its creator David Korn. This shell is able to do most of the things both the Bourne, and C Shell can do, and improves on them. For instance, the history feature is available, plus you are able to call up the history, edit the command, and then re-run it.

'bash'
The Bourne-Again Shell. This is probably the most widely used shell to date, and is the default shell for most newer Linux distributions. Again it integrates most of the above features and improves upon them. It was developed by the Free Software Foundation.

There are many other shells out there, but chances are if you are using a UNIX style operating system, you are using one of the above mentioned shells. My personal favourite is the bash shell, which also happens to be the first one I was exposed towards, so I may be biased. However typically when shell scripting, I use the korn shell because of its programming friendly structure.

How do you know what UNIX shell I am using?

Type "ps" and then hit return at your shell prompt and you should get something similar to:

$ ps
PID TTY TIME CMD
13087 pts/1 00:00:00 bash
13121 pts/1 00:00:00 ps

The numbers under PID, TTY, TIME etc should all be different from machine to machine, and the number of lines of programs running may also. But one line you have will be probably "bash" "csh" "sh" "ksh".

Another way to check is to type the following:

grep your-user-name /etc/passwd (eg grep ken /etc/passwd)

Which will return you something along the lines of:

ken:x:501:501:Ken:/home/ken:/bin/bash

The last portion of that line is '/bin/bash' which tells you your default shell when you login.

Ken Dennis
Ken.Dennis@Gmail.com
http://KenDennis-RSS.homeip.net/

In The News:

This RSS feed URL is deprecated, please update. New URLs can be found in the footers at https://news.google.com/news

TechCrunch

Investment advisory software developer SigFig raises $50 million ...
TechCrunch
SigFig, the developer of an automated wealth management toolkit, has raised $50 million in a new round of funding. The company said the new money would be ...

and more »

Engadget

GitHub Education is a free software development package for schools
Engadget
GitHub, the online, open-source code repository recently acquired by Microsoft, has already made big moves to support future software developers. In 2012 it launched the Student Developer Pack, in 2015 it built the GitHub Classroom for teachers, and ...

and more »

Clarkson prof in Potsdam leading team to evaluate DNA software
North Country Now
POTSDAM -- A Clarkson University professor is working with a $75,000 grant to lead a team in evaluating differences in the results given by a variety of software programs used to analyze mixed DNA samples. Clarkson University Associate Computer Science ...


Investor's Business Daily

Red Hat Downgraded, Cloud Computing Growth May Hit Legacy Software
Investor's Business Daily
The enterprise software maker reports fiscal first-quarter earnings late Thursday. Analysts estimate profit growth of 21% to 68 cents a share, with revenue rising 19% to $897 million. At its analyst day in May, the company said its emerging technology ...
Oracle, Micron, FedEx and More Earnings Coming This Week24/7 Wall St.
The Week Ahead: Pharma IPOs Galore, Blackberry Earnings And MoreBenzinga
Benzinga's Top Upgrades, Downgrades For June 19, 2018Benzinga
Zacks -GlobeNewswire
all 123 news articles »

ZDNet

Two weeks with the OnePlus 6: Useful buttons, gorgeous design, stellar software, and reasonable price
ZDNet
Speed and updates: OxygenOS provides nearly a stock Android experience with software customizations that make the device even better than stock. The software screams and in the short couple of weeks of using it I have seen updates so the default ...


hcanews.com

AI Diabetes Tech Continues FDA's Software Push
hcanews.com
Last year, the agency announced the launch of a precertification pilot program, with the goal of approving and bringing potentially life-saving software to market more quickly. Major names like Johnson & Johnson, Apple, and Fitbit signed on as ...

and more »

GeekWire

Owl Insights raises cash for mental health treatment software platform
GeekWire
The company, which is incorporated under the name Mental Health Data Services, makes software that supports mental health treatment in a variety of settings. GeekWire has reached out to Owl Insights for more information on the funding and will update ...


Award-Winning ONYX 18 Software Now Shipping
What They Think
Salt Lake City, Utah – Today, Onyx Graphics, Inc., announced global availability of ONYX 18, the newest version release of the company's award-winning wide- and grand-format software that includes new color technologies for color accuracy, consistency, ...


WPRI 12 Eyewitness News

Major UHIP software upgrade delayed again
WPRI 12 Eyewitness News
PROVIDENCE, R.I. (WPRI) - A major software upgrade for Rhode Island's troubled UHIP computer system that was scheduled for this weekend has been delayed again. Ashley O'Shea, a spokesperson for the Executive Office of Health and Human Services, ...
State delays software upgrade of UHIP systemTurn to 10

all 34 news articles »

512tech.com

Austin logistics software firm Convey lands $10 million to break into new markets
512tech.com
Convey, whose software platform helps online retailers manage shipping logistics, has raised $10 million to break into new markets. The Austin-based company received the funding from Silverton Partners, Techstars Venture Capital Fund, RPM Ventures, ...

and more »
Google News

Lotus Notes Domino and Web: Application Development ? Tips for Programmers

Beginning with Domino version R4 it has integration with the... Read More

Unwanted Files

A LOT OF UNWANTED FILES.When you uninstall an item of... Read More

MySQL for Beginners ? How to Create a MySQL Database

Whether you are an experienced web programmer or a complete... Read More

Why Java RDBMS?

It is a well known fact that Java as a... Read More

Google Brings the Earth to Your Desktop

Google Inc. has launched a new software package that allows... Read More

Microsoft Great Plains Integration Manager ? Advanced Techniques

Great Plains Integration Manager scripting and translation - overview for... Read More

10 Programming Tips

(1) Avoid using the same variable again and again for... Read More

Your Computer May Be Infected, Heres How To Check (NOT about virus)

NOTE: Please take time to read on - it may... Read More

Reporting for Microsoft Great Plains/Dynamics/eEnterprise: RW ? ReportWriter ? Tips for Developer

Microsoft Business Solutions Great Plains is written in Great Plains... Read More

Linux Secrets

The first thing that you will notice about Linux Red... Read More

SQL scripts for Project Accounting: Microsoft Great Plains series ? overview for developer

Microsoft Business Solutions Great Plains has Project Accounting module where... Read More

15 Questions to Ask Your Software Vendor

When making a decision to buy any piece of software... Read More

Brief Notes About Mainframe Software Pricing

We don't think about mainframe software pricing anymore, we just... Read More

Microsoft CRM Implementation - US Market Lessons

Microsoft CRM is CRM answer from Microsoft Business Solutions. If... Read More

Do You Want Your Own Fully Programmable ERP? - Part 1

We are in a transition phase in the Managerial Administration... Read More

What is Software Piracy?

There are several kinds of software piracy. The bottom line... Read More

Cisco Certification: Five Things To Do DURING Your CCNA Exam

There are plenty of articles out there about how to... Read More

Linux Dual Boot-How To Format

Just the thought of a duel-boot scares many people away,... Read More

Review of TikiWiki Content Management System

TikiWiki is open source software - it is written in... Read More

The Importance of Timely Timesheets

Whether you are a small consultancy firm, a medium sized... Read More

Reloading Windows XP

If you have been running Windows XP for a couple... Read More

Unofficial Windows 98 SE Service Pack 2.0 RC2

Microsoft has never released a service pack for Windows98 SE,... Read More

MultiNational Corporation ERP Implementation ? Microsoft Business Solutions Great Plains

If you look back to the history, you will see... Read More

Software For Your Hard-Drive

All your software is stored on a hard-drive. But how... Read More

Great Plains Dexterity Programming ? Overview For Developer

Looks like Microsoft Great Plains becomes more and more popular,... Read More