Process-use the ps command to view process information

This option combination will display the process information of each user. using these options without the prefix will enable the command to run in "BSD" mode

Introduction

The ps command has many options. the simplest format is as follows:

[Allyes_op @ allyes ~] $ Ps

PID TTY TIME CMD

1079 pts/2 00:00:00 bash

1114 pts/2 00:00:00 ps

In this example, the two processes correspond to the bash and ps commands respectively.

By default, the output information of ps commands is not many, but the process information related to the current session terminal is output.

Before introducing other options of the ps command, let's take a look at other fields output by the ps command:

TTY: indicates the control terminal of the process.

TIME: indicates the total cpu time consumed by the process.

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Ps x

Adding the x option will tell the ps command to display all processes without worrying about which terminal they are controlled.

The output result adds a new column named STAT, which displays the current state of the process.

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STAT status

R	Running status. The process is running or is ready to run.
S	Sleep status. The process is not running, but waiting for an event, such as inputting a keyboard or receiving a network packet.
D	Uninterrupted sleep status. Processes are waiting for I/O operations, such as hard drive
T	Paused. The process is instructed to be paused.
Z	Invalid or zombie process.
<	High-priority process. Processes can be assigned more importance and more CPU time.
N	Low-priority process. The time to use the processor can be obtained only after other higher-priority processes use the processor.

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Ps aux

Another common option combination is aux.

This option combination will display the process information of each user. using these options without the prefix will enable the command to run in "BSD" mode.

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BSD mode field information

USER	User ID
% CPU	CPU usage percentage
% MEM	Memory usage percentage
VSZ	Virtual memory consumption size
RSS	Actual memory size, in kb
START	Process start time. If the value exceeds 24 hours, the date is used for display.

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