How to Sort by PID in htop Linux?

The htop command-line utility is a powerful, interactive process manager for Linux that allows users to monitor system resources and manage running processes in real time. While htop defaults to sorting processes by CPU usage, you can easily change this behavior to organize the list by Process ID (PID) number instead. This article provides a quick, step-by-step guide on how to sort your process list by PID using both keyboard shortcuts and the interactive setup menu.

Sorting by PID Using Keyboard Shortcuts

The quickest way to change the sorting order in htop is by utilizing built-in keyboard shortcuts. This allows you to reorder the process list instantly without navigating away from the main screen.

• Open the Sort Menu: Press F6 (or O on some keyboard layouts) while htop is running. This opens a sidebar menu on the left side of the terminal listing all available column criteria.
• Select PID: Use the arrow keys to scroll up or down the list until PID is highlighted.
• Confirm: Press Enter. The process list will immediately rearrange itself in ascending order based on the Process ID numbers.

Sorting by PID Using the Setup Menu

If you prefer a more permanent configuration or want to adjust how columns are displayed, you can use the main setup interface.

• Enter Setup: Press F2 (or S) to open the configuration screen.
• Navigate to Display Options: Use the arrow keys to select Display options from the Setup column.
• Adjust Sorting: Move over to the right-hand columns to find the default sort direction settings. You can combine this with the F6 menu to ensure htop behaves exactly as needed for your troubleshooting workflow.

Quick Alternative: The Interactive Clicking Method

If your terminal emulator supports mouse interactions and you have mouse tracking enabled in htop, you can simply click directly on the column headers. Clicking the PID column header at the top of the process list will automatically sort the table by that column. Clicking it a second time will reverse the sort order between ascending and descending.