•There are no real limits to file name lengths, but users should be careful with nonalphabetic characters.

•Files that begin with ‘.’ are often system files (like ‘.login’), and should not be deleted, moved, or created unless you are sure that is what you want to do.

2.2.3 Advanced Concepts

•Besides the normal keyboard operation, some keys have special meanings. Erasing a character can be done with delete/rubout or backspace /control-h (^h), the actual key varies from machine to machine. Control-s (^s) and control-q (^q) are for flow control, typing a ^s will stop output to the screen, which can then be continued by typing ^q. ^d represents end-of-file, and is used to exit from several programs like mail, or possibly to log off the computer.

•Most workstations run the UNIX operating system, which comes in two varieties: 4.3BSD (Sun) and System V (SGI), whose differences are minor for the average user (except for printing). When one logs into a UNIX system, you are actually running a program (shell) this is in some ways similar to DOS. In the standard shell you are given a prompt, where you type your command. If it is not a built-in command, it searches on the disk according to a user-specified search path, for an executable program of that name. Almost all commands are programs that are run in this manner. There are also executable shell scripts, similar to command files on DOS. UNIX is limited to running a program of a size equal to the sum of its memory, and swap space. As the system is multi-tasking, any program (or part thereof) that is not currently being run when extra memory is required, is swapped (moved) out to the disk, until it is ready to run again.

2.3 THE NETWORK

•Because the computers are on a network, they each have a unique identification.

•Each machine has a name, for example one of the machines is called ‘claymore.engineer.gvsu.edu’. The short form of this name is ‘claymore’. The machine also has an equivalent number ‘148.61.36.215’.

•you can log into other machines. Try ‘rlogin ws1’. This allows you to sit at one machine, and use many others, even around the world.

•you can also use a number of other commands which will allow network access,

rusers look at other users on the network

2.4 GOOD MANNERS

• Check your mail on a regular basis - your e-mail address is

your_login_name@river.it.gvsu.edu

•Do not run big programs on computers somebody else is using

•Keep your directory nicely structured

•DELETE ALL FILES THAT ARE NO LONGER NEEDED. We only have 200 Megabytes, and it will be used up faster than you think. Check your own disk usage with ‘du ~’. Check the

total area available with ‘df .’. Check your quota with ‘quota -v’

• Compress all your big files using ‘compress *’. Uncompress them with ‘uncompress *’