.SH "Common Commands" .P Commands consist of a program name, possibly followed by a sequence of arguments. Arguments are sequences of characters separated by blanks or tabs, and are generally file names or options. The way in which commands react to different arguments is set out in detail later in this manual ("AGSM System Guide"), "UNIX Users Guide" or the green UNIX Programmers Manual. .P The following is a list of the most common commands used on the system. .LB 10 0 0 0 .LI ls \&'ls' lists all of your files. This command is often used to find the size of the files. If you use 'ls -l' you may get the following (-l is an option which means to give a long or full listing) .DS % ls -l total 2 -rw------- 1 joe 48 Nov 24:13:05 fred -rw------- 1 joe 72 Nov 24:13:16 junk % .DE This tells you, among other things, who owns the file (ie 'joe') how many characters are in the file (48 in "fred", 72 in "junk"), and the date of last modification of the file. .LI "who" \&'who' gives the names of all the users using the system at the moment. .DS % who johno tty6 Dec 04 12:01 root tty8 Dec 04 12:06 joe ttyi Dec 04 11:48 plip ttyn Dec 04 13:34 jack ttyo Dec 04 12:46 larry ttyp Dec 04 12:12 % .DE This indicates who is logged on, which terminal they are using, and when they logged on. This command is also useful for determining whether a user you wish to write to is logged on. .LI "date" This command is used to find the time and date. .DS % date Mon Dec 04 13:49:40 Sydney Time 1978 % .DE .SK .LI "pp" This command gives general information about your account. .DS % pp Password and Lnode structures for UID: 1234 <-- 1 LIMITS: Process Limit: 5 <-- 2 Core Limit: 64 Kbytes Processes: 2 <-- 3 Line Printer: 20 Printer units <-- 4 Disk Allocation: 100 units <-- 5 Disk Overshoot: 100 units Disk Usage: 5 units <-- 6 GENERAL: Encrypted Password: "do884r9e" Warnings: 0 Total Connect Time: 1d13h Total CPU Time: 0h30m Account last used at: Mon Dec 04 08:20:46 1978 Valid terminal groups: a STRINGS: Login name: joe Initial directory: /user3/stewed.ants/joe Initial shell: /bin/sh Names: Joe Cool .DE .P Message #1 indicates the number by which you are known to the system and corresponds to each user name. .P Message #2 tells you how many processes you can have going at any one time. A process is something which uses the machine, ie. any command you type in is a process. Because you are logged on you have the shell program going interpreting your commands. This is also a process. .P Message #3 tells you how many processes you had going when "pp" was typed in. .P Message #4 indicates the number of line printer pages you can print at any one time. .P Messages #5 and #6 tell you, how many "disk units" you are allocated (maximum space for your files), and how many "disk units" you are currently using. A "disk unit" is related to the number of files you have, and to their size. .LI "passwd" This command is used to change your password. You should change your password regularly (every month or so), using words of at least eight characters. The use of several words is also highly recommended. Typing in 'passwd' will produce the following .DS Old password: New password: Check: % .DE You will have to specify the old password, (this is again a security measure) and a new password. When 'Check:' is printed you must enter the new password again, just in case you have misspelt it the first time. No characters are printed when you type the passwords in. .LE pack, unpack .LB 10 0 0 0 "" 0 .LI pcat These three commands are used to save space. The first of these commands (pack) will attempt to compress the file into a smaller space without losing any information. This is very useful when you are reaching your disk limit. If packing a file will not save space the system will not pack it. Packing files works best on large files, as these save larger amounts of space than when smaller files are packed. The second command (unpack) is the reverse operation of "pack". When a file is packed, a suffix of ".z" will be appended to the file name. This is to indicate that the file has been packed. If you try to cat a packed file, you will only get garbage coming up as it is a binary file (see sect X.X). You must not edit or lpr a packed file. This is why the command "unpack" is used. An example of the use of "pack" and "unpack" is given below .DS % ls fred junk.z (this is a packed file) % pack fred (will now "pack" fred) fred: 35% compression (indicates space saved) % ls fred.z junk.z % unpack junk (will now unpack "junk") % ls fred.z junk % .DE A word of warning! 'cu Do not edit any packed file. You run the risk of destroying the file if you do (it has happened before). Before you do anything with any packed file you must unpack it. The only exception is pcat. .sp Pcat is used to view packed files when it is not required to unpack the file. If you typed .DS % pcat fred.z .DE the contents of "fred" will be printed on the terminal. This command in no way changes any files, it only prints the contents of the specified packed files. It can be given any number of file names, just as in 'cat'. .LE