Managing files with the Krusader twin-panel file manager

Handy Commander

By Matej Urbancic

Diego Cervo, Fotolia

Krusader is a graphical file manager based on the twin-panel paradigm. The Krusader file manager was created early in 2000 by two enthusiastic programmers who wanted a graphical twin-panel file manager for the KDE environment and couldn't find one.

The concept of a twin-panel file manager (which is also called an orthodox file manager) is not a new concept. The first twin-panel file managers emerged back in the mid 80s, with the now legendary Norton Commander, which was an inspiration for many text and graphical file managers. Among the first graphical versions that followed was the also legendary Windows Commander, which is now known as Total Commander for MS Windows.

In *nix systems, the grandfather of all orthodox file managers is Midnight Commander, or mc for short. Several projects are currently developing a diverse assortment of commanders in various programming languages.

Figure 1: The Krusader user interface offers a twin-panel design.

What Is Krusader?

Twin-panel file managers like Krusader are often called commanders. They are easily recognized by a basic structure consisting of left and right file panels on top and a bottom command-line panel. Even though the design is easy to understand, the functionality is difficult to implement, since a commander offers a wide spectrum of actions and features.

The goal is to execute each action with the minimum number of keystrokes, and the output must be as informative as possible. The two panels are the active (or source) panel and the inactive (or destination) panel. The panels are connected to each other; in other words, executing a command in one panel results in an action in the other panel. Additionally, every action must show the result without refreshing the view.

This connection between the left and right panels has many advantages, but the most important advantage is speed. When you move a file, you only need one key press or mouse click. The file manager executes the command from source to opposing destination in the other panel. Because the view does not change and the windows do not cover each other, the file simultaneously appears in the destination panel and is, at the same time, removed from the source panel. In more advanced uses, such as synchronization, space calculation, and ftp, the functionality is similar.

The real advantage of an orthodox file manager is its integration with the keyboard. Krusader is designed to function with little or no dependence on the mouse. The extensive collection of keyboard shortcuts, combined with keyboard steps for navigating the directories, makes Krusader much more efficient for an experienced user than the single-panel equivalents. Another important feature is the useraction system, which allows the user to extend and adjust Krusader to meet personal needs and further minimize key strokes needed to perform frequent operations.

It is sometimes said that an orthodox file manager inhabits the middle ground between a conventional file manager and command line. Krusader offers the simplicity of the command line with the visual orientation of a graphical interface.

Figure 2: You can customize Krusader with the KDE Konfigurator utility.

Getting Started

Krusader is included with many of the most popular Linux distributions, so check to see if you already have it before you download it. If you don't have Krusader already, you'll find source code, as well as packages for Gentoo, Debian, Fedora, and Slackware, at the Krusader website [2]. The installation page [3] has additional information.

In addition to providing the benefits of orthodox file management for KDE, Krusader offers advanced features, including support for synchronization, as well as file and directory comparison. Krusader comes with alternative protocols through KDE kioslaves, such as fish, ftp, and sftp, and includes support for a variety of archive formats. Krusader supports various integrated checksum calculation and verification tools, and it can handle associations to many common file types.

To truly experience the advantages of Krusader, you need to use the keyboard because Krusader really is designed for the keyboard user. Most basic actions are covered with function keys F1--F10.

Krusader also comes with an advanced integrated search engine capable of searching files and the text inside of them. You can apply as many filters to the search as needed.

All basic required information, such as occupied space, size, permissions, and dates, are readily updated on the main window. This format has many advantages, but the most obvious is that you can use a similar interface for different operations. Whether you work with file systems, archives, transfer protocols, or other virtual file systems, the usage and interface stay the same.

Krusader takes the middle road between advanced features and user friendliness. The Krusader team is currently working on integrating operations that will let users place time-consuming tasks into the background.

Also planned are enhanced regular expression features that will allow users to automate frequently recurring actions, as well as descriptive tooltips and support for the metadata of the most popular file types.

Figure 3: Convert your CDs with the audioCD KIO slave.

Conclusion

Krusader might be branded an advanced file manager, but it really is easy to use. The twin-panel paradigm is highly effective for a user who knows how to operate from the keyboard. Krusader also has a regular upgrade cycle, releasing new stable versions several times a year.