Skip to content

The top/htop command

top is the default command-line utility that comes pre-installed on Linux distributions and Unix-like operating systems. It is used for displaying information about the system and its top CPU-consuming processes as well as RAM usage.

htop is interactive process-viewer and process-manager for Linux and Unix-like operating system based on ncurses. If you take top and put it on steroids, you get htop.

Comparison between top and htop:

Feature top htop
Type Interactive system-monitor, process-viewer and process-manager Interactive system-monitor, process-viewer and process-manager
Operating System Linux distributions, macOS Linux distributions, macOS
Installation Built-in and is always there. Also has more adoption due to this fact. Doesn't come preinstalled on most Linux distros. Manual installation is needed
User Interface Basic text only Colorful and nicer text-graphics interface
Scrolling Support No Yes, supports horizontal and vertical scrolling
Mouse Support No Yes
Process utilization Displays processes but not in tree format Yes, including user and kernel threads
Scrolling Support No Yes, supports horizontal and vertical scrolling
Mouse Support No Yes
Process utilization Displays processes but not in tree format Yes, including user and kernel threads
Network Utilization No No
Disk Utilization No No
Comments Has a learning curve for some advanced options like searching, sending messages to processes, etc. It is good to have some knowledge of top because it is the default process viewer on many systems. Easier to use and supports vi like searching with /. Sending messages to processes (kill, renice) is easier and doesn't require typing in the process number like top.

Examples:

top

  1. To display dynamic real-time information about running processes:

top

  1. Sorting processes by internal memory size (default order - process ID):

top -o mem

  1. Sorting processes first by CPU, then by running time:

top -o cpu -O time

  1. Display only processes owned by given user:

top -user {user_name}

htop

  1. Display dynamic real-time information about running processes. An enhanced version of top.

htop

  1. displaying processes owned by a specific user:

htop --user {user_name}

  1. Sort processes by a specified sort_item (use htop --sort help for available options):

htop --sort {sort_item}

Syntax:

top [OPTIONS]

htop [OPTIONS]

Additional Flags and their Functionalities:

Short Flag Long Flag Description
-a
-
Sort by memory usage.
-b
-
Batch mode operation. Starts top in 'Batch mode', which could be useful for sending output from top to other programs or to a file. In this mode, top will not accept input and runs until the iterations limit you've set with the '-n' command-line option or until killed.
-h
-
top --user {user_name} Only display processes owned by user.
-U
-user
Help.
-u
-
This is an alias equivalent to: -o cpu -O time.

Last update: 2022-05-12
Back to top