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CHAPTER 8 Staying Informed About System Activity

If you choose, you can obtain details about the computer's activity. In particular, you can find out how busy the computer is, who is logged in, and what other users are doing. The information you receive depends on the UNIX workstation or host you are logged on to.

Getting Basic System Information

The uptime command displays some information regarding the status of the computer: the time, how long the machine has been up and running, the number of users currently logged on, and the load average. As more users log on to the system and do work, the load average tends to increase. This gives you a rough idea of how busy the system is.

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$ uptime                                                             
10:24am  up 4 days, 4 min  4 users, load average: 0.00, 0.04, 0.00   
$                                                                    
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The load average numbers are for 1 minute, 5 minutes, and 15 min CPU cycles received. So in the above example, the 1 minute CPU cycles received is 0.00; the 5 minutes CPU cycles received is 0.04; and the 15 minutes cycles received is 0.00.

Finding Out About Other Users

The who command displays who is currently logged in to the computer. From left to right, the first entry is the user's login name, followed by that person's terminal (tty), and the date, time, and location of the login.

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$who                       
smith ttyq1 Oct 08 10:33   
jones ttyq2 Oct 08 08:22   
root  ttyq3 Oct 08 09:51   
$                          
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The command whoami displays only the line of information for the user who is logged on to that terminal. This is useful in finding who is logged on to an unattended terminal.

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$ whoami   
smith      
$          
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The w command lists all the users on the system and what they are doing. The first line is essentially the uptime command output. For more information on what the fields in the user lines are, type man w at the system prompt.

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$ w                                                                          
10:27am & 6lup 4 days, 4 mins, 4 users, load average: 0.00, 0.04, 0.00   
User  tty   login@  idle JCPU PCPU what                                      
smith ttyq1 10:23am   47   2:15  w                                           
jones ttyq2 11:45am        3:35  csh -v view                                 
$                                                                            
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To find out more information about particular users, use the finger command. When you use the command finger with no arguments, you get abbreviated information (full name, tty, idle time, login time, office) for each user on the system. If you use the command finger with a username as an argument, that user's .project and .plan files also display. (See section 3.)

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$ finger                                                   
Login Name         TTY Idle When                           
smith John Smith   q1       Mon 10:23                      
jones Smith Jones  q2  4    Mon 09:51                      
root  Super User   q3  51   Mon 09:04                      
$ finger smith                                             
Login name:  smith             In real life:  John Smith   
Office:  Bldg 4 D560 x2345   Shell:  /bin/csh              
On since Oct 8 10:23:50 on ttyq1 from 134.3.130.197        
58 seconds Idle Time                                       
Plan:                                                      
:                                                          
<displays user .plan file>                           
$                                                          
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A text editor can be used to add messages or information to the .project and .plan files in your home directory. (For details, see section 5.) These files should only contain information that you would like other users to know about you. Also, be sure that you give permission for others to read your .project and .plan files. If you don't, people who finger your username will not be able to see the information you include in your files. (See section 3.7.2 for more information.)

Also see historical information up to and including yesterday about performance and usage of RS6000/AIX computers (e.g., the Batch Farm, general interactive servers, NFS and AFS servers, tape servers, etc.) that are maintained by SCS. Please note these are accessible only to SLAC nodes.

 
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