Course: COSC513 Operating Systems
Name: Deyong Xu
This article is just an introduction of Unix operating system to people who don’t any knowledge about Unix operating system . Generally speaking , people don’t need to understand too much about the details about a software or a system , the most important thing is people should know how to use these software or systems as a user . So what I’m going to do is to offer a little help to people who know nothing about Unix system and try to use Unix system as a tool in their work .
Over the past few years , Unix operating system has gained unprecedented popularity . The reason why Unix operating system is so popular is it allows more than one person to use the computer at the same time which means it’s a multiuser operating system , and it allows a person to communicate directly with the computer via a terminal which means it’s interactive . So it allows a group of people working together on a project to share selected data and programs , while keeping other information private .
When users learn a new software , what they concern mostly is how to use utility tools which the software offers and how to deal with files they create and operate on . So the next I’m going to talk about is whole idea about Unix operating system and its file structure . Major ideas about Unix operating system
First of all , Unix operating system is a multitasking , multiuser , and multichoice operating system . Multitasking means one user can run more than one program at the same time . Users don’t have to run their programs one by one , they can do together . Multiuser means that more than one user can operate on Unix operating system at the same time , and this is the reason why Unix operating system gained popularity in the past years . The last character of Unix operating system is multichoice which means that Unix operating system have different shells such as C-shell and B-shell etc . Reader maybe just wonder What a shell is . The shell is the utility that processes your requests . when you enter a command line at a terminal , the shell interprets the command and calls the program you want . Because separate users can use different shells at the same time at a system , a system can appear different to different users . The choice of shells demonstrates one of the powers of Unix operating system : the ability to provide a customized user interface .
The utilities of Unix operating system
Unix utility program allow you to work with the Unix system and manipulate the files that you create . Some of utilities allow you to communicate with other people using he computer . The following utilities I will introduce is the most useful utilities . These are : man , who , write , mesg , mail , cp lpr , date , echo , sort . Man : display how to use the utility you want to use and forget how to use . eg : $ man who
This command displays information about who utility .
Who : display a list of the users currently logged on .
Write : to send messages to another user who is logged on .
eg : $ write mike
Hi mike , how are you ?
Mesg : mesg n / y , if you don’t want other user to interrupt you by sending messages to you , this command will give other users permission of sending messages to you . Mail : to send mail to other users , whether or not they are logged on . Cp : to make a copy of a file .
eg : cp sourece-file destination-file
Lpr : to place a file in the printer queue for printing .
Eg : $ lpr report
Date : to display the current time and date .
Eg : $ date
Echo : to copy to the terminal anything you put on the command line after echo . Eg : $echo Hi
Sort : to put the contents of a file in order by lines .
Eg : $ cat days
$ sort days
cat : to display the contents...