Introduction to UNIX

Getting the most out of the Physics and Astronomy computers will require at least a little knowledge of UNIX. Don't worry, it's painless.

Here are some UNIX commands:

Command	Description
`ls`	lists the files and subdirectories in the current directory
`pico filename.txt`	a simple text file editor, hit control-X to save and exit
`rm filename`	removes (deletes) the file called "filename"
`cd subdir`	change the current directory to subdir
`cd ..`	change directory to the parent directory
`cd`	without an arguments, this sends you to your home directory
`mkdir dirname`	make a subdirectory called dirname
`rmdir dirname`	remove a subdirectory called dirname
`lpr filename.ps`	sends a postscript file to the printer
`lpd`	view the print queue, and JOBNUMBERS
`lprm JOBNUMBER`	used to remove a print job from the queue
`passwd`	change your password

Using these commands, you could try the following exercise:

Task	Thing to Type
Make a subdirectory called 'animals'	`mkdir animals`
Go into that new directory	`cd animals`
Create a text file called cow	`pico cow`
Now type something bovine and hit...	`control-X`
List the file you have created	`ls`
Print the file	`lpr cow`
Remove the file you have created	`rm cow`
List the now empty directory to confirm the deletion	`ls`
Change to the parent directory again	`cd ..`
delete the animals directory	`rmdir animals`

The behavior of UNIX commands can be modified using 'options'. For example, if you want to list not only the 'normal' files, but also the 'hidden' files, try the following:

ls -a

Or to get a more detailed listing of your files, try:

ls -l

To learn more about the options for a given command, try typing:

man commandname

That will get you the online manual page.

If you want to close one of your extra text windows, type:

exit

If you type exit or logout in your primary login window, it will log you out of the system.

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Introduction to UNIX