From the Gloucester Linux User Group Website

6. Working with Processes

Utility definitions

The Mandrake Guide has a section on using ps

"Report on active processes. Note that you do not need to include a - before options. In options, list arguments should either be separated by commas or be put in double quotes. In comparing the amount of output produced, note that e prints more than a and l prints more than f." (O'Reilly)
The Mandrake Guide also has a section on using pstree.
The Mandrake Guide also has a section on using top

"Provide information (frequently refreshed) about the most CPU-intensive processes currently running. See ps for explanations of the field descriptors." (O'Reilly)
The Mandrake Guide also has a section on using kill and killall.

"This is the /bin/kill command; there is also a shell command of the same name. Send a signal to terminate one or more process IDs. You must own the process or be a privileged user. If no signal is specified, TERM is sent." (O'Reilly)
"Kill processes by command name. If more than one process is running the specified command, kill all of them. Treat command names that contain a / as files; kill all processes that are executing that file." (O'Reilly)
Usually add to the end of a command to make the command run in the background, leaving the prompt free for the next command. A better explanation is avalible at the guide.
A full description is avalible at
Give details of processes that are running in the background. A full description is avalible at
fg and bg are covered in the Mandrake Guide to using job control
A full description is avalible at
"Execute a command (with its arguments) with lower priority (i.e., be "nice" to other users). With no arguments, nice prints the default scheduling priority (niceness). If nice is a child process, it prints the parent process's scheduling priority. Niceness has a range of -20 (highest priority) to 19 (lowest priority)." (O'Reilly)
"Control the scheduling priority of various processes as they run. May be applied to a process, process group, or user (target). A privileged user may alter the priority of other users' processes. priority must, for ordinary users, lie between 0 and the environment variable PRIO_MAX (normally 20), with a higher number indicating increased niceness. A privileged user may set a negative priority, as low as PRIO_MIN, to speed up processes." (O'Reilly definition)
"Accept output from another command and send it both to the standard output and to files (like a T or fork in a road)." (O'Reilly definition)

Other online resources

There is an article covering most of this at, and a more involved one at Linux World

To do:

SourceForge LogoWant to suggest improvements, resources, contribute or comment on this article? Please do.