System Administration Guide

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 such administrative tasks as determining how to set process priorities, and how to kill processes that have hung or become inactive.

Depending on which options you use, ps 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

Table 63-1 describes some of the fields reported by the ps command. The fields displayed depend on which option you choose. See ps(1) for a description of all available options.

Table 63-1 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's ID.
`C`	The processor utilization for scheduling. This field is not displayed when the `-c` option is used.
`CLS`	The scheduling class to which the process belongs: real-time, system, or timesharing. This field is included only with the `-c` option.
`PRI`	The kernel thread's scheduling priority. Higher numbers mean 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 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.

The ps Command

The `ps` Command