In Linux systems, viewing running processes can be achieved through multiple commands. 1. Use ps to view the current terminal process, such as ps to display basic information, ps -u to display detailed resource occupation; 2. Use top to view all processes in the system in real time and sort them dynamically; 3. Use htop to provide a more intuitive and interactive interface (need to be installed); 4. Use pgrep to quickly find specific processes and their PIDs. Different commands can be used for different scenarios: use ps for temporary viewing, use top or htop for real-time monitoring, and use pgrep for accurate search.

Viewing running processes in Linux systems is a common operation for troubleshooting problems, optimizing performance, and managing systems. There are several commands that can quickly implement this, and the key is to understand the purpose and output format of each command.

Use the ps command to view the current terminal's process

ps is one of the most basic and commonly used commands to view processes. It only displays processes in the current terminal session by default.

For example, enter:

 ps

You will see an output like this:

 PID TTY TIME CMD
 1234 pts/0 00:00:00 bash
 5678 pts/0 00:00:00 ps

• PID is the process ID.
• CMD is the command name that starts the process.

If you want to see more information, such as user, CPU, and memory usage, you can use:

 ps -u

This command is suitable for viewing the current user's process and is not suitable for global monitoring.

Use top to view system processes in real time

If you want to dynamically view all running processes in your system, top is a good choice.

Just enter:

 top

You will enter a real-time update interface and you can see:

• CPU and memory usage for each process
• Process status (run, sleep, etc.)
• Overall system load status

In this interface, you can sort by CPU usage by P and by M by memory usage.

If you exit, just press the q key.

Use htop to view a more intuitive process list (recommended installation)

htop is an enhanced version of top , with a more friendly interface, supporting mouse operation and color highlighting.

If not installed, you can install it through the package manager, for example on Debian/Ubuntu:

 sudo apt install htop

Then run:

 htop

Its advantages include:

• Support scrolling to view the full command line
• You can use the arrow keys to select the process and send a signal (such as terminating the process)
• Clearer colors to distinguish different types of processes

Quickly find specific processes with pgrep

If you just want to know if a service or program is running, you can use pgrep .

For example:

 pgrep sshd

If there is a matching process, the corresponding PID will be output; if there is no, there will be no output.

You can also display the process name in combination with the -l parameter:

 pgrep -l python

This can quickly locate whether the process you are looking for exists.

Basically these are the methods. Different commands can be selected in different scenarios: use ps for temporary viewing, use top or htop for real-time monitoring, and use pgrep for specific processes. By mastering these tools, you can easily meet the needs of most viewing processes.

The above is the detailed content of How to list running processes in Linux. For more information, please follow other related articles on the PHP Chinese website!