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This article will explain in detail the method of viewing process commands on linux. The editor thinks it is very practical, so I share it for you as a reference. I hope you can get something after reading this article.

The commands for linux to view processes are: ps command to view static process statistics, top command to view process dynamic information, pgrep command to query process PID information according to conditions, and pstree command to view process tree information.

A program is a static collection of executable machine code and data stored in an external storage medium (such as a hard disk), while a process is a computer program that executes dynamically in CPU and memory. In Linux systems, one or more processes can be created after each program starts. For example, a httpd program that provides Web services may create multiple processes to provide services when a large number of users visit the Web page at the same time. Next, we will describe in detail how to view process commands in Linux.

View the process

Use different command tools to view the status of the process from different angles.

Commonly used process view commands

(1) ps command

Used to view static process statistics

Common options are as follows:

A: displays all the process information under the current terminal, including the processes of other users.

U: use a user-based format to output process information.

X: displays the progress of the current user under all terminals.

-e: displays all process information in the system.

-l: displays process information in long format.

-f: displays process information in full (full) format.

It is important to note that some of the options do not have a "-" prefix (adding "-" prefixes may have different meanings). It is customary to combine the above options, such as "ps aux" or "ps-elf"

Example: ps aux will display process information in the form of a simple list. The figure below is as follows

In the output information in the above figure, the title of the first behavior list, where the meaning of each field is described as follows:

USER: the name of the user account that started the process

PID: the ID number of the process, which is unique on the current system

TTY: on which terminal the process runs. "?" The table is unknown or no terminal is required

STAT: shows the current state of the process, such as S (hibernating), R (running), Z (dead),

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