htop Command in Linux

Monitoring system resources is an important task for Linux developers and system administrators. The htop command provides an interactive process viewer that makes it easier to monitor running applications and system resources.

Unlike a basic process listing, htop provides an interactive interface where users can scroll through processes, sort them, search for specific processes, and perform actions on selected processes.

What Is htop?

htop is an interactive, terminal-based process viewer for Linux and other supported platforms.

To start it, simply run:

htop

The interface provides information about running processes along with CPU and memory-related information.

Why Use htop?

htop is useful when you need to:

• Monitor CPU and memory usage.
• Identify resource-intensive processes.
• Search and inspect running processes.
• View processes in a tree structure.
• Troubleshoot server performance problems.

Useful htop Features

Process Search

You can search the displayed processes to quickly find a particular application or command. The manual documents F3 or / for incremental process searching.

Tree View

Tree view helps you understand the relationship between parent and child processes.

You can start htop with:

htop -t

The -t option enables tree view.

Sort Processes

Processes can be sorted by different columns, making it easier to identify applications consuming significant resources.

For example:

htop --sort-key PERCENT_CPU

The exact available sort keys depend on the htop version.

Filter Processes

You can filter processes using the command line:

htop --filter=php

This can be useful when monitoring a specific application or service.

htop vs top

Both htop and top are used for process monitoring.

top is widely available and provides a traditional terminal interface. htop offers a more interactive experience with easier scrolling, searching, tree views, and mouse support.

Best Practices

Use htop together with commands such as free, df, du, and ps when troubleshooting Linux servers.

When you identify a resource-heavy process, investigate why it is consuming resources before terminating it. Avoid killing critical system or application processes without understanding their purpose.

Conclusion

The htop command is a powerful and user-friendly tool for monitoring Linux processes and system resources. Its interactive interface makes it easier to identify CPU and memory usage, search processes, view process relationships, and troubleshoot performance issues.

For Linux server administration, htop is a useful addition to the standard command-line toolkit.