Monitoring Processes With ps

Monitoring Processes With ps

The ps -ef command allows you to look at all the processes currently running on your system.The output of ps -ef follows the format shown in Table 7-1:

Output format of the ps -ef Command
Name PID PPID C Time TTY CPU Time Process
joe 23328 316 1 May 5 ttyq1 1:01 csh

Output format of the *ps -ef* Command
Name	PID	PPID	C	Time	TTY	CPU Time	Process
joe	23328	316	1	May 5	ttyq1	1:01	csh

In this table, the process shown is for the user ''joe.'' In a real situation, each user with processes running on the system is represented. Each field in the output contains some useful information.

Name: The login name of the user who ''owns'' the process.
PID: The process identification number.
PPID: The process identification number of the parent process that spawned or forked the listed process.
C: Current execution priority. The higher this number, the lower the scheduling priority. This number is based on the recent scheduling of the process and is not a definitive indicator of its overall priority.
Time: The time when the process began executing. If it began more than 24 hours before the ps command was given, the date on which it began is displayed.
TTY: The TTY (Terminal or window) with which the process is associated.
CPU: The total amount of CPU time expended to date on this process. This field is useful in determining which processes are using the most CPU time. If a process uses a great deal in a brief period, it can cause a general system slowdown.

For even more information, including the general system priority of each process, use the -l flag to ps. For complete information on interpreting ps output, see the ps(1) reference page.