ps

ps

The ps command, short for „process status“, is used to display information about currently running processes on your system. This includes details such as process IDs, user accounts associated with them, CPU usage, memory consumption, and more.

Basic Use Case

You can use the ps command in various forms, depending on your needs. Here are a few basic examples:

• ps: This will display information about all running processes for the current user.
• ps -ef: This option displays detailed information about every process on the system.
  • -e means to list all processes (-e stands for „all“ in some systems, while others use it as a long format option).
  • -f is used with other options like -e, -u, or -p and causes ps to display detailed information about each process.

Advanced Use Cases

For those familiar with filtering processes based on criteria like user names (-u) or specific IDs (-p), the following examples illustrate how versatile ps can be:

• ps -fu username: Displays all processes running under a specified user account.
• ps -fp process_id: Shows detailed information about a process identified by its ID.

Special Hacks

If you’re dealing with a system where there are many processes and want to see them in a more readable format, here’s a trick:

• Use ps aux or ps -efl instead of ps auxf. The latter provides more information about each process but in a less cluttered way compared to the traditional output of ps aux.

Necessity Level

Understanding and mastering basic uses of the ps command is essential for Linux users at an intermediate level. This includes system administrators, those who manage their own servers, and developers who work on their local machines. For beginners, learning about ps can be a bit challenging without prior knowledge of Linux processes and how they are managed.

Therefore, I would categorize the necessity of this command for different levels of experience as follows:

• Beginner: Not immediately necessary but useful to know.
• Intermediate: Essential to understand basic usage and filtering options.
• Advanced: Familiarity with more advanced options like -fu or -fp can be helpful in specific scenarios.

Remember, practice is the best way to become comfortable with any Linux command. Experimenting with ps will give you a good grasp of its capabilities and how it fits into your daily Linux work.