You can jump to longer descriptions of cheat sheet items by clicking on the links at each item's beginning.
More detailed information starts here.
The focus of this document is on making screenshots of free software (to be uploaded to Wikimedia Commons, for example) and the many ways of changing the user environment to accommodate such tasks.
This writeup requires that the user is reasonably knowledgeable around Linux, or at least computers in general. The notes are primarily about CD variants of Knoppix. Because these are supposed to be "quick notes", the informative warnings and suggestions have less significance and are thus in smaller type and lighter colour. If you're using a different LiveCD, then Knoppix-specific notes might not apply to you.
Important features deprecated in Knoppix 6.0 and since
If you’ve used a Knoppix LiveCD before, but you’re new to Knoppix 6.x, then note that since this branch of Knoppix, development has taken a different path and many things you’d expect from using earlier releases are missing.
The desktop= startup parameter to choose an alternative non-default window manager does not work — at least in the CD release, and the restartx program ("Restart Knoppix in different window manager") is not there either. OTOH, restarting X to see changes that need restarting works now through init (see point #7 at the top of the page).
Custom live sessions are impossible, because saveconfig doesn't exist, and so automatically saving and restoring settings to and from external storage (USB stick) doesn't work. Cumbersome workarounds: Save (some) settings manually, or save the whole Knoppix CD-image to a hard drive or another storage device.
Because of all that, all the files you've created/saved must then also be saved to external storage (USB stick, local hard drive, or online), if you don't want to lose them.
Likewise, if the hard drive is belly-up perhaps, and you don't have a memory stick, but a good network connection, then use cloud services (if they still work with an older browser), but they impose their own limits on how much you can store away for free and how much you can upload at a a time. Iceweasel settings can be saved to Firefox Sync.
When choosing a cloud service, choose the one that has an open-source-friendly company behind it, where the service is known to work well with Firefox/Iceweasel. Good cloud services set file and document permissions to private by default. Some files you might like to share with friends and family, or the public.
When using free Wi-Fi or a connection you don't have complete trust in, use secure browser connections where available for web-based services and other sites (https: and the like).
The Knoppix 6.7 CD does not include Wine anymore!
If you plan to use Knoppix for a longer while, then the Suspend feature of very modern Knoppix 6.x releases — particularly 6.7.1 and newer — works well, though it has to be started from the Logout menu. An additional best practice is to quit all applications when using Suspend. (Haven't tried the Hibernate functionality.)
1. To avoid shadows in screenshots and other graphical gimmicks (they take their own time, too), use the no3d startup parameter. The visual effects are generated by compiz.
Compiz also contains useful functions, while most effects , visual or otherwise, can be turned off.
If there is a need to use compiz without most graphical effects, launch without the no3d option.
CompizConfig Settings Manager is the go-to program to disable graphical effects; accessible via Start > Preferences or the ccsm command.
Knoppix 7.0.5
The only caveat in at least this version of Knoppix would be window shadows. In CompizConfig Settings Manager (CCSM), these are governed through Effects > Window Decoration [sic].
There, the next logical step would be not allowing shadows for any windows at the Shadow windows field, by specifying !any . Unfortunately, it does not apply to all window items: most actual windows still carry shadows.
Setting Shadow Radius and Shadow Opacity to a minimum does not help, because setting them to 0 by typing the 0 value and pressing the tab key will set them to 0.1000 and 0.0100, respectively. So this does not work in CCSM.
The solution is to make changes in the gconf-editor. In Knoppix 7 the default configuration editor is now dconf Editor; while the Gconf Editor is not included in the programs menu anymore. Nevertheless, it can still be accessed by using the gconf-editor command (either from the Run dialog or in the command line). The Gconf Editor works, but is not particularly stable (version 3.0.1), perhaps owing to possible conflicts with dconf-editor.
In gconf-editor, go to
/apps/compiz/plugins/decoration/allscreens/options
There, set both
shadow_opacity and
shadow_radius to 0
To remove title bar translucencies (these apply to metacity theme decorations), go to
/apps/gwd/
There, set
metacity_theme_active_opacity and
metacity_theme_opacity from 0.75 (or any other value less than 1) to 1
In addition, disable (uncheck) the following settings:
metacity_theme_active_shade_opacity and
metacity_theme_shade_opacity
The changes should be instantaneous.
active and shade stand for active window title and inactive window title, respectively.
2. If you’re not living in a mainly English-speaking country and your native language is not English, then the first part is usually setting the keyboard layout (applies to most all versions of Knoppix):
The following sets the keyboard layout to Estonian and Russian, with Windows-style switching using Left-Alt+Shift. Layout switching is optional and thus highlighted.
$ setxkbmap -layout ee,ru -model pc105 -option grp:alt_shift_toggle
Layout indicator and switcher (in LXDE): Left-click on the clock, choose Panel Settings, switch to Panel Applets tab, click Add button, choose Keyboard Layout Switcher from the list. Default option shows language flag, but can be changed to language code, if desirable.
Fork of Firefox. Note that the default Iceweasel UI settings in Knoppix deviate from the default Firefox (Iceweasel) UI appearance.
3. Remove the very annoying “Missing Plugins” infobar (Iceweasel 3.0 or newer):
about:config
plugins.hide_infobar_for_missing_plugin
toggle to true
4. For Iceweasel (and its screenshots) to be in a different language, a langpack must be installed. Depending on version. go to
ftp://ftp.mozilla.org/pub/mozilla.org/firefox/releases/6.0.2/linux-i686/xpi/
If your Iceweasel version number is different, change it to x.x.x in the URL. Just in case, make sure that the chosen language pack (or any other xpi) also matches your Linux architecture.
5. To temporarily launch Iceweasel in a different UI language:
$ iceweasel -uilocale nl &
I haven't found yet any way to make this more permanent than that, since a substantially more temporary nature of Knoppix 6.x and newer makes this a moot point.
The Google.com background picture works with Iceweasel 3.5 or newer (so definitely not Knoppix 6.0.1, which has Iceweasel 3.0).
6. (Iceweasel 4.0 or newer): Go to www.youtube.com/html5, opt in. The process is cookie-based, so in another operating system or browser a user can still view Flash videos.
YouTube has made a push for most all of its videos to be available in WebM (VP8) format. It’s also faster to download, because it uses better compression. This works really well in Linux (oddly, not so in Windows xp, even if Firefox version is 10). Note that some videos are not available in WebM and may still require Flash or Gnash.
7. I sometimes use Knoppix to make screenshots and often I can't use application icons of a program that has its logos trademarked. Typically, the program at issue is Mozilla Firefox.
Yes, there is Iceweasel, but I know for sure that Mozilla releases ready-made binaries of Firefox, while Iceweasel usually has only source packages which are then built (compiled) by package maintainers of various distributions.
What I needed is to make sure I could change window decorations to something nicer than the default for the duration of the session; this here does not make it permanent, and various Knoppix 6.x releases have had issues with that.
Knoppix 6.0.1/OpenBox
The following applies to Knoppix 6.0.1 and later versions that use Openbox as the built-in window manager.
Change the LXDE window manager from compiz to openbox-lxde:
$ sudo vi /etc/xdg/lxsession/LXDE/config
[Session]
window_manager=openbox-lxde
Restart X with init 2 and init 5 (these require sudo or the root terminal window).
After that you're free to start the Openbox Configuration Manager (obconf) from the taskbar menu and select whichever window decorations you like (there are several). You can see the immediate effect on all existing windows as you click on different window decoration themes. obconf also allows to choose which title bar buttons to display and how.
Knoppix 6.7.1/Metacity (quick and dirty edition for now)
While in this version of Knoppix changing window themes does not necessarily require the use of a command line, it requires making oneself familiar with GConf Configuration Manager (Start > System Tools > Configuration Editor or gconf-editor &).
Primer
Knoppix 6.7.1 has changed its window manager from OpenBox to Metacity.
Themes are usually located at
/usr/share/themes
Which themes are listed and which are available
Now, Metacity in the CD version of Knoppix 6.7.1 seems to have been gutted of (a) useful visual tool(s) to view and change window decoration themes. Strangely, it's still possible to view these themes, but with the help of a command line:
Use
ls /usr/share/themes
to list all the theme names and folders;
Use
metacity-theme-viewer themename &
Replace themename with the name of the theme/folder (the ampersand & serves to separate the program window from the terminal window at app launch).
Each folder has a varying amount of theme files: some folders only contain window widgets, some both, and some only window decorations (borders and title bar).
To spare you the chore of finding out which window decoration themes are available in Knoppix 6.7.1, I've listed them here:
Strangely, the default or fallback theme is Simple; Clearlooks is specified by default in settings, but is not available, and the Default-named theme is itself missing.
Now, the GConf Configuration Editor (gconf-editor) looks very similar to the Windows Registry Editor; with the difference that all the various settings are saved in user-editable text files.
To change a theme, go to
/apps/metacity/general
in the GConf tree, then on the right pane, look for the Theme parameter. It can be changed by clicking into the value and typing in the theme name to one of the themes listed above. The effect should be immediate. The change happens only when a typed name matches a theme that has existing files for window decorations; otherwise, no change occurs.
Another useful parameter is the button layout, especially if you want to make screenshots with non-free app icons. The layout syntax differs from that of OpenBox. I chose this:
:minimize,maximize,close
Now, the button layout I specified removes the window menu button (the item is just called 'menu'), which also typically contains the app icon. Removing the window menu button is important when making screenshots of open source software that have their logos trademarked (typically Firefox).
Knoppix 7.0.5/Metacity
Themes
The method of viewing Metacity themes is the same as described in instructions above for Knoppix 6.7.1. The list of themes available in Knoppix 7.0.5 is placed way below.
But changing themes is slightly different:
Instead of GConf Configuration Manager (gconf-editor) the LXDE menu now sports the dconf Configuration Editor.
Fortunately, though, gconf-editor is still available and can be accessed through the Start > Run command.
To launch dconf Editor, go to Start > System Tools > dconf Editor, or use dconf-editor & in the command line (notice the change in just one letter).
The preference tree nomenclature and positioning is also slightly different; go to
org.gnome.desktop.wm.preferences
There, change the theme parameter; changes should be instant.
Table listing themes for window decorations that can be used in the CD version.
The requirement is that the theme not use application icons and that it sport square edges to avoid including leftover visuals when round edges are involved.
Description of columns:
• Themes new compared to Knoppix 6.7.1 are formatted in a light green text background colour.
• App icon? shows whether a theme uses application icons. When testing out various themes, I learned that there were several that don't use app icons. This is a good thing, as now it won't be necessary to change the title bar button layout. Above instructions to change the button layout will remain for reference.
• Edges refers to whether a theme uses round or square edges. With windowed applications, visible remnants of rounded areas are also included in screenshots, which may make the window appearance inconsistent to people not familiar with the nature of the theme.
Theme name | App icon? | Edges | Notes |
AgingGorilla | No | Square | Appears distorted. |
Atlanta | Yes | Square | |
Bright | Yes | Square | |
Clearlooks | Yes | Round | |
ClearlooksClassic | Yes | Round | Looks very, very similar to Clearlooks |
Crux | No | Square | Appearance classic to the early first decade of 2000's |
Esco | Yes | Square | |
Glider | Yes | Square | Slightly buggy |
Glossy | Yes | Round | Similar to Clearlooks, with appearance true to its name |
Indubstrial | Yes | Square | Industrial and Indubstrial are both very similar |
Industrial | Yes | Round | |
Metabox | No | Square | Best choice in Knoppix 6.7.1. |
Mist | No | Square | A bit similar to Metabox; the window menu button is now more intuitive. Best choice overall. |
Simple | Yes | Square |
Screen resolutions
In some cases, one must change the screen resolution to something lower than the default (such as 1280x800, in a 16:10 aspect ratio), so that the resulting screenshot image would be smaller. This is especially useful, as elements in screenshots will be more visible, even when the image is a thumbnail.
Within Knoppix, the "Monitor Settings" icon between aumix and the taskbar is the one.
Knoppix 6.7.1 uses the lxrandr tool, while Knoppix 7 has ARandr. For some reason, the latter combination offers non-standard resolutions compared to those offered in Knoppix 6.7.1. I don't yet know if it's the result of different video adapters or different X.org versions. ARandR does offer some resolutions that somewhat align to the 16:9 aspect ratio; one of them is 848x480 (roughly corresponds to 1280x720).
For some reason, Knoppix 7.0.5 won't react to custom screen resolution startup parameters. So without much further effort, you're stuck using ARandR.
8. As I recently started real-life testing of Knoppix 7.0.5, I discovered to my great dismay serious issues around input device stability, where both the pointing device and keyboard worked intermittently (the keyboard was more stable, so it kinda saved me from greater embarrassment).
And I only attributed my problems to just the shaking of the train, while I wasn't using swap at all...
The hardware involved was hp Pavilion dv5204ea, with a Synaptics touchpad.
Well, if it's buggy, then you're testing it.
I don't know what causes this intermittency or what is the reason for it.
In such a case, the best solution is going back to Knoppix 6.7.1, even if some of the software there is not quite up-to-date.
Admittedly, the above hardware is six or so years old, and this latest (as of February 2013) Knoppix worked ok (ok, I won't say fine) with newer hardware, specifically a Samsung R20 notebook (has a dual-cure CPU and stuff), so it seems that the bug does not apply to all hardware. Planned obsolescence, I say :\
The quick collation of materials to help in changing window decorations in Knoppix 6.0.1 was moved to
Knoppix 6.0.1 window decorations old issues.