User commands and logs
As you might guess from the name, the
groups command extracts selected information from the
/etc/group file and displays it (Figure 9). With no options,
groups lists information for the current user, but a valid username can be used as an option instead.
For some reason, the
finger command is not installed by default on the desktops of many distributions. However, if you are administering a multiuser system, it is well worth installing.
Without the use of any options, or with the
-s option (Figure 10),
finger followed by an account name lists the login name, the name, the interface, how long the user has been idle, when they logged in, their office, and their office phone number. If, like many home users, you leave the name, office, and office number blank when you create users, these columns will, of course, be empty.
-l option, you get the same information reformatted, plus the user's home directory and login shell, as well as the last time they received internal mail. For administration work, this option is probably the most useful.
One of the most useful commands for gathering information about users,
w, is also one of the simplest. It shows what processes a user is running at the time the command is run.
w command plus a username (or omitting a username and defaulting to the current account) produces a table of information for the user (Figure 11). From left to right, the information is the user account, its terminal, its remote host (0 if none exists), the login time, the length of idle time, the JCPU or time used by all processes attached to the terminal, the PCPU or time used by the current process, and the name of the current process.
If you choose, you can run a shorter summary by using the
-l option. The information displayed using the
-l option omits the login time, the JCPU, and PCPU.
Buy this article as PDF
New partnership will bring more and better CS training to US schools
Criminals offer online help over Tor network
Sophisticated malware is still present on Joomla and WordPress sites around the world.
Future versions of Ubuntu's code service will support the popular Git version control system used with Linux and other open source projects.
New release marks the arrival of AMD’s unified driver strategy.
A new study by IDC charts big changes in the big hardware market.
Azure CTO says Redmond has already considered the unthinkable.
Lead developer quells rumors that the Debian version is slated for center stage.
MSBuild is now just another GitHub project as Redmond continues its path to the light.
Malware could pass data and commands between disconnected computers without leaving a trace on the network.