PC Plus HelpDesk - issue 269

Paul Grosse This month, Paul Grosse gives you more insight into some of the topics dealt with in HelpDesk.

From the pages of HelpDesk, I look at:

  • Scaling large images;
  • Video screen capture;
  • Burning ISOs;
  • Linux with Wine; and,
  • Killing windows.


Scaling large images

If you regularly print out large image files from Internet Explorer, you might encounter problems with the image running off the right and side and the bottom, rendering the printout useless. So, how do you get it to print out the whole image?

This problem used to occur when people bought a new monitor and changed the screen resolution - Internet Explorer altering the size of the printed image so that it was bigger.

However, you can get around this without changing resolutions just by going into print preview - click on the down-arrow to the right of the printer icon on the toolbar then select 'Print Preview...'.

In that view, you have the option to adjust the page margins by dragging the markers that appear just outside the edge of the page (you need to have the full page view to do this because they disappear if you select the full page width view), or, you can change the scale of the image.

Just select 'Shrink To Fit' from the drop-down menu and your image will fit on the page.

At print resolutions of 300dpi, a scale change of a few per cent is not going to cause moire-like banding on the printout.

Video screen capture

Video screen capture on Linux is easy and, of course, free with Istanbul.

Capturing video to demonstrate something is always more effective than just static pictures alone - I bet you can't wait until the pages of PC Plus are in such a form.

On Linux (here in Ubuntu), there is a program called Istanbul that will record an area of the screen for you.

Start it by clicking on 'Applications', 'Sound & Video', 'Istanbul'.

Right-click on the red dot on the taskbar to see the options and select the area to record - this appears as a red rectangle as you drag it and if you get it wrong, you can always reselect it.

When you are ready, click on the red button to start the recording process and get on with whatever you are supposed to be doing, whether it is demonstrating how to get the computer to do something unusual or displaying your outstanding abilities at Tetris.

When you have finished, click on the stop button (the square in the taskbar that the red circle became) and save the video to the place of your choice.

The video is saved at 10 frames per second using the Ogg Theora video codec which has a mime type of 'video/x-theora+ogg' for your web pages.

Ogg is included in the upcoming HTML5 standard and it is worth noting that Ogg has no issue with patents or patent royalties (thanks to an irrevocable and free license) so you can put them on your website freely.

If you want to look at the video (it illustrates the use of the video rather than my abilities at playing Tetris) then just click here to open up a directory in a new window.

Burning ISOs

If you are trying to burn an ISO image file (such as those for KNOPPIX or OpenBSD and so on) to CD under Windows Vista - you might find it tempting to insert the CD and then drag the ISO file and drop it onto the folders directory of the CD in Windows Explorer.

However, when you have finished burning it and reboot the machine, it will look at the CD and then the BIOS will just take you straight to where it normally goes - usually Windows (even though the BIOS is set to boot from the CD first). So, what's going wrong?

The CD/DVD support on Windows is very rudimentary and saving files is made so easy that it seems the natural thing to drag an ISO disc image onto File Manager and think that it has done what you want it to.

However there is a subtle difference.

When you save a file, you put it into a file system that Windows has already constructed for you on the CD (as in the 'CD/DVD for saving data' example in the diagram on the right).

An ISO image (as in the '.ISO file' example in the diagram) already has that structure within it and is literally an image of the whole CD, including any boot files that are necessary.

All that the CD burner program has to do is to copy it, sector for sector onto the CD (which is how it appears in the last diagram on the right - the way it should be). That way, on boot up, when the BIOS needs to read a sector from it, it does so directly and will boot.

If you just save it as a file (as in the 'CD/DVD with .ISO file "saved"' diagram on the right), the BIOS will not see the ISO's boot files it needs and go onto the installed hard drives to look for an OS or bootloader.

ISOs are usually used to produce installation discs for installing UNIX-like OSes such as Linux, Solaris, and *BSD so Windows would have no need for the capability because Windows is the only OS you will ever need. Apparently.

You can install a proper Windows executable CD/DVD ISO burning program for free.

There is a list of ISO burners at www.windowsmarketplace.com/results.aspx?text=.iso&WT.mc_id=iso .

If you are lucky enough to know someone with Linux already installed, you can use the K3B CD/DVD burner which is very easy to use.

Linux with Wine

Using Windows programs in Linux is not as difficult as it sounds, thanks to the emulators that you can use.

The best known of these is 'Wine'.

To install a Windows program from a browser (here, we'll use Firefox), all you do is click on the download link and when Firefox opens the file, select 'Open with wine (default)' and click on 'OK'.

The program then runs and installs itself as it would on Windows, all from a pseudo c:\ directory in your home '.wine' directory if you want to find it.

From the main menu, the program appears under the 'Applications', 'Programs', program-name.

If your program runs as full screen, as many games do, but you want to run it in a window (as the program in the screenshot on the right is doing), just press [Alt][Enter] as you would if you were running Windows.

We'll leave it as an exercise for you to see if you think that programs run with higher frame rates under Linux with Wine.

Also, as you are running with the security of Linux, if the program turns out to be malicious, it only affects resources that you have access to, limiting it effectively to your own home directory.

Killing windows

If you sometimes get a window that won't die, you can kill it off by using things other than the little 'X' button that is usually in the top right of the Window, on the title bar.

If you don't know, from the command line, you can grep a list of processes for a process (here, hypothetically called 'progname') by name by entering ...

ps aux | grep progname

... or, more concisely by using the dedicated function pgrep like so ...

pgrep progname

... which will give you a list of PIDs from which you can choose one to kill.

Alternatively, if you have a process that is gobbling up processor time, you can see it by using 'top' which will display the process list according to how much processor time the programs are using.

Pressing 'K' will freeze the list and allow you to kill the process by typing in its PID.

However, if a program has multiple windows or you have several copies of the same program running, there is a more explicit way of doing this.

At the command line, type 'xkill' and the mouse will change to the skull and crossbones, allowing you to click on the offending window and kill that program.

The only thing that can go wrong is that the program terminates itself and the window disappears before you have a chance to kill it thus leaving you with an armed and dangerous mouse that will kill the first thing it clicks on. If you think this might happen, you can always open up another window beforehand (such as a terminal or text editor) so that you can click on that if necessary.

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