Red Flag Linux Desktop 6.0 User manual: Process and Job control

Simply put, a process is the process of executing a program or task. In a Linux system, executing any command creates one or more processes, that is, the command is implemented through the process.

The multitasking concept of Linux operating systems can be better understood from a process perspective. For http://www.aliyun.com/zixun/aggregation/13879.html "> system administrators, the management system process is an important part of day-to-day management."

Viewing process status in the system with PS

By using the PS command to observe the state of the process, the status of the current instantaneous process is displayed. Depending on the information displayed, you can determine which process is running, whether a process is suspended, or how long the process has been running, the resources the process is using, the relative priority of the process, and the process's identification number (PID) ... This information is useful to the user and is more important to the system administrator.

The general usage of the PS command is:

ps [option [arguments] ...]

The PS command has the following key parameters:

Without any options, the PS command lists the PID of each process associated with the current shell, with the following results:

PID TTY Time CMD

596 pts/0 Unlimited Bash

627 Pts/0 Unlimited VI

628 Pts/0 Unlimited PS

Where the meanings of each field are as follows:

--PID: Process identification number

--tty: Start the process's terminal number

--time: reports the cumulative CPU time used by the process

--cmd: Executing process name

To obtain a complete list of process information, you can use the PS command with the following options:

Ps–aux

In addition to listing the above fields, the CPU usage (%CPU), Memory usage (%MEM), virtual image size, host DataSet size (RSS), terminal number (TTY), status (STAT) are listed.