Beginners guide to Unix

What is UNIX ?

UNIX is a multitasking operating system which allows multiple users to works together. It arrived much before than DOS and Windows. It has a very different working environment compared to windows. It demands a certain level of commitment from its users. One interacts with UNIX via a command interpreter known as the shell. You have to enter the command in the shell to execute them. The best thing of UNIX is that it lets you combine commands and use them as English language lets you to join two works to generate a meaning full idea. But the problem one often faces with UNIX is that it does not warn whether you are right or wrong. It does not make you aware about the consequences of your actions. Perhaps this is the reason that most do not prefer UNIX.

Windows gain preference over UNIX due to the enriched Graphical user interface (GUI). In order to overcome this weakness "X-window" was introduced to UNIX.

Basic Commands in UNIX

The format of commands used in UNIX is like these $ command – [options] arguments. Options will add different utility to you command. (Example $ ls will show you a list of your files at that location where as $ ls –l will show you all the files in a long format). Arguments are essential in case of some commands only.

Commands related to Files

Arguments are essential in case of some commands only.
• ls --- makes a list of your files
• ls -l --- makes a list of your files in long format containing lots of useful information, e.g. the who owns the file and who has the right to look at it, exact size of the file, when it was last modified.
• ls -a --- lists all files, including the ones whose file names begin in a dot, which you do not always want to see.
You can also join to commands and use them together for example ls-la (instead of using ls-a or ls -l).
• rm --- remove file
• cp --- copy file
• mv --- move file
• gzip --- zip file
• gunzip --- unzip files
• wc --- Word count in a file
• view --- view file

Commands related to Directories

• cd --- change directory
• mk –-- make directory
• cd ..--- go up the directory

Commands related to Users

• who --- shows you the details of all the users online
• uname --- Operating system in use
• uname –r --- current release of the operating system implemented in the machine
• uname –n --- hostname of the machine

Other useful commands

• date --- shows you the current date on your machine
• cal --- shows you the calendar of that month

The man command is a very important command. By using the man command you can get hold of all the details of a particular command.
$ man command (example $ man ls)man command shows all the possible ways of using a particular command with their options. In case of any query regarding any command a person can use the man command (it provides the manual for a command.). To exit from the man page the press" q" and then press "enter" key.

Complete detail of any command is available as a manual in the operating system itself. This makes UNIX very special.