Red Flag asianux Server 3 System Management: command-line Operations (iv)

1.6 Process and job control commands

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 a 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

You can see the status of the process through the PS command, which will show the state of the current instantaneous process. Depending on the information displayed, determine which process is running, which 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 users, and for system administrators

More important. 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 for each process associated with your current shell. The results are as follows:

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 times 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, it also lists CPU usage (%CPU), Memory usage (%MEM), virtual image size, host DataSet size (RSS), terminal number (TTY), status (STAT), and so on.