4.5. Summary

Linux is a multi-user, multi-tasking operating system that has a UNIX-like way of handling processes. Execution speed of commands can depend on a thousand tiny things. Among others, we learned a lot of new commands to visualize and handle processes. Here's a list:

Table 4-3. New commands in chapter 4: Processes

atQueue jobs for later execution.
atqLists the user's pending jobs.
atrmDeletes jobs, determined by their job number.
batchExecutes commands when system load level permits.
crontabMaintain crontab files for individual users.
haltStop the system.
init run levelProcess control initialization.
jobsLists currently executing jobs.
killTerminate a process.
mesgControl write access to your terminal.
netstatDisplay network connections, routing tables, interface statistics, masquerade connections and multicast memberships.
niceRun a program with modified scheduling priority.
pgrepDisplay processes.
psReport process status.
pstreeDisplay a tree of processes.
rebootStop the system.
reniceAlter priority of running processes.
shutdownBring the system down.
sleepDelay for a specified time.
timeTime a command or report resource usage.
topDisplay top CPU processes.
uptimeShow how long the system has been running.
vmstatReport virtual memory statistics.
wShow who is logged on and what they are doing.
wallSend a message to everybody's terminals.
whoShow who is logged on.
writeSend a message to another user.