[linuxkernelnewbies] Development [LWN.net]

[Peter Teoh]

http://lwn.net/Articles/313050/ Development [LWN subscriber-only content] BleachBit: Does GNU/Linux need the equivalent of a Windows registry cleaner? January 6, 2009 This article was contributed by Bruce Byfield On Windows, configuration options are stored in the registry, and are arcane enough that most people use a specialized editor, or cleaner, to remove unnecessary information. Recently, in a blog entry, Andrew Ziem argues that GNU/Linux needs the equivalent of a registry cleaner on Windows. He does so by pointing out examples of files and directories that remain in your home directory even after a package is deleted, and offers his new program BleachBitas a solution. However, while BleachBit -- currently at version 0.2.1 -- is easy enough to use, you have to wonder whether the minimal disk spaced saved or the privacy gained by running it is worth the effort -- especially when such advantages come with the risk of accidentally deleting information. BleachBit is available as source code, or as packages for various recent versions of CentOS, Debian, Fedora, Mandriva, openSUSE, and Ubuntu, as well as SUSE Linux Enterprise and Red Hat Enterprise Linux. At 16 kilobytes, it downloads almost instantly. It is enough of a standalone program that, if necessary, you can install the different .DEB and .RPM packages on a wide variety of other distributions. As an application, BleachBit is largely self-explanatory. You select an operation from the left hand pane, reading a brief description of it in the right hand pane if necessary, and click the Preview button to see what will be deleted, then the Delete button to actually remove files and directories. Operations complete in well under 20 seconds, even if you choose all of them. The list of applications that BleachBit cleans is a long one, and grows with each release. In the current version, the supported applications include Bash, Beagle, Epiphany, Firefox, KDE and OpenOffice.org. BleachBit also supports proprietary applications, such as Flash and Opera, as well as desktop caches and recent document lists. Among those not supported are GNOME and Mozilla Thunderbird -- although, to be fair, BleachBit is in rapid development, and is only likely to increase its support in later releases. The BleachBit interface is also in development. The descriptions of operations would be more visible with word wrapping, and, although a generic warning that deleted files cannot be recovered appears before anything is deleted, a confirmation specific to your choices -- and, perhaps, suggesting that you preview first -- might also be order. Even more importantly, you should be aware that BleachBit does not clear your choice of operations after they are complete, even when you close and restart the application. That means that, unless you check carefully, you could easily find yourself performing an unintended operation, all the more so because the list of operations requires scrolling to see every item, even when the BleachBit window is maximized. Similarly, you need to remember that selecting a top-level operation, such as Firefox, selects a number of other operations, not all of which you necessarily want. Useful, redundant, or dangerous? The real question about BleachBit is not so much how to use it, but whether it is needed or even advisable to use. Ziem himself admits in his blog entry that "there is no promise your system will run much faster" if you use BleachBit -- and that "much" seems a euphemism for "any," if the results on my test systems are any indication. After all, unlike an unneeded entry in the Windows registry, most unused configuration files on GNU/Linux are simply not accessed, and therefore have no effect on system performance. True, running BleachBit can free up hard drive space. However, because many configuration files are plain text, in many cases the space freed is measurable in kilobytes. The largest savings is likely to be in browser caches, but the total freed space is unlikely to be more than a gigabyte or two, an amount barely noticeable on recent computers. So, unless you are temporarily in need of more storage space until you can get out and buy an external drive, are on a network where your available space is limited, or take an anal-retentive pleasure in cleaning your system, you may find the saving of hard drive space a less than compelling argument for BleachBit. If you don't miss the space occupied by unnecessary files, then you won't see much need to reclaim it. Probably the best argument in favor of BleachBit is the ease with which it protects your privacy. Many programs, such as Firefox, have their own controls for clearing associated files, and, if nothing else, you can set a file manager to view hidden files, and cherrypick the ones you want to delete manually. Yet, whether you wish to hide your viewing habits or simply believe in privacy, the convenience and efficiency of cleaning everything in your home directory from a single window is undeniable. By using the Preview, you can even learn from BleachBit the location and name of configuration files, which is more than you can say for many desktop administration utilities. However, as with any desktop utility, the danger of BleachBit lies in putting power in the hands of users who may not be fully aware of what they are doing. Fortunately, unlike cleaners of the Windows registry, BleachBit does not affect system configuration, so it is not going to leave you with an unusable system if you accidentally delete the wrong file. Still, a mistake made when running BleachBit could mean the loss of valuable information stored in configuration files. After all, the whole point of having a BASH history is so that you don't need to recall or retype a command you have recently used. Similarly, if you miss that Sign ons under Firefox in the operation pane includes bookmarks and recently visited URLs, you could easily lose information that you were counting on being preserved. Moreover, such mistakes are all the easier to make because of BleachBit's interface deficiencies (see above). Personally, I would be much more assured about BleachBit if these deficiencies were corrected, and actions within the application were hedged with more warnings and reviews of what you are about to do. Some users might complain about such additions, but making an application idiot-proof is a basic requirement if you are going to offer desktop users the power to make sweeping changes. After all, no matter what our experience, we can all be idiots sometimes, especially if tired or rushed. Conclusion None of these concerns are necessarily reasons to avoid BleachBit. Personally, I end with mixed feelings about the application. Possibly, BleachBit is an example of how following the Windows analogy too closely can lead to programs of minimal use. Alternatively, perhaps it empowers users to do what is otherwise more difficult and time-consuming, and allows them to protect their privacy without having to learn about their systems. Possibly, both could be true at the same time. But, perhaps in the long run, the value of an application like BleachBit lies less in any improvements in performance or privacy that it offers than in the discussion of desktop and system design it provokes. Packages should be removing all traces of themselves when they are removed, but, as Ziem observes, many are not. Perhaps what is needed is not a tool like BleachBit, but stricter policies by distributions about the scripts that packages run before they are removed.