Using the ps Command (System Administration Guide: Advanced Administration)

System Administration Guide: Advanced Administration

Using the `ps` Command

The ps command enables you to check the status of active processes on a system, as well as display technical information about the processes. This data is useful for administrative tasks such as determining how to set process priorities.

Depending on which options you use, the ps command reports the following information:

Current status of the process
Process ID
Parent process ID
User ID
Scheduling class
Priority
Address of the process
Memory used
CPU time used

The following table describes some fields that are reported by the ps command. Which fields are displayed depend on which option you choose. For a description of all available options, see the ps(1) man page.

Table 12–2 Summary of Fields in ps Reports


Field	Description
`UID`	The effective user ID of the process's owner.
`PID`	The process ID.
`PPID`	The parent process ID.
`C`	The processor xutilization for scheduling. This field is not displayed when the `-c` option is used.
`CLS`	The scheduling class to which the process belongs such as real-time, system, or timesharing. This field is included only with the `-c` option.
`PRI`	The kernel thread's scheduling priority. Higher numbers indicate a higher priority.
`NI`	The process's `nice` number, which contributes to its scheduling priority. Making a process “nicer” means lowering its priority.
`ADDR`	The address of the `proc` structure.
`SZ`	The virtual address size of the process.
`WCHAN`	The address of an event or lock for which the process is sleeping.
`STIME`	The starting time of the process in hours, minutes, and seconds.
`TTY`	The terminal from which the process, or its parent, was started. A question mark indicates that there is no controlling terminal.
`TIME`	The total amount of CPU time used by the process since it began.
`CMD`	The command that generated the process.