Tuesday, June 24, 2014

Create a simple animated GIF in Linux

From scottlinux.com.

Install imagemagick, put your images in a folder, and in a terminal run:
$ convert -delay 100 -loop 0 <frame1>.gif <frame2>.gif <animated>.gif
 (Slightly modified from the link above so I can remember how I did it.)

Saturday, June 21, 2014

GUIs broken in Debian Jessie

After an update recently, I noticed that some GUIs were broken.
Astute readers may recognise that all the broken GUIs use QT (KeePassX, Skype and VirtualBox).

The solution I found was to install qt4-qtconfig and change the GUI Style from Desktop Settings (Default) to GTK+.
Here are the same applications after the fix:
VLC was also affected, but curiously undoing the change did not break the GUI again as it did with the applications in the screenshot.

Sunday, June 15, 2014

External DVD drive not detected in Debian Jessie

The CD/DVD drive in my laptop long since packed in working, so I bought a cheap external drive from Amazon. (£12.99, free delivery.)

I plugged it in and ...nothing. The drive did not appear in Thunar. I thought I might have wasted my money on a drive that is not compatible with Linux, but then I tried VLC and that played the DVD all right. After that, the drive was mounted and visible in Thunar.

However, I tried the same thing today and could not get VLC to play the DVD I was trying to play. And it is really frustrating trying to solve a problem like that with a five year old girl asking you every 15 seconds if you have managed to play her Dora the Explorer DVD yet.

Eventually I had to give up, suspecting that the cheap drive might have broken. After lunch I tried booting into a Crunchbang Live USB, and to my relief found the drive was automounted and working.

I noticed the default name for the drive in Crunchbang was dev/dvd, so booted back into Debian and tried that: it worked.

But still the drive didn't automount. Later on, after aforementioned small child had watched Dora and chanted the obligatory mantra of "Swiper, no swiping!" three times plus various other exhortations and was sated, I managed to find the solution to the problem in a more leisurely period.

It seems there's a bug in Jessie which means drives are not auto detected.

Solution found on the Debian Forum.

The solution is near the end of the page, specifically:
To determine if kernel polling is enabled:

    cat /sys/module/block/parameter/events_dfl_poll_msecs
    cat /sys/block/sr0/events_poll_msecs

If you get 0 or -1 from both of those commands, kernel polling may be disabled.

To enable kernel polling permanently (survives a reboot), add the following command to your /etc/rc.local file (anywhere before the 'exit' line in that file):

    echo 2000 > /sys/module/block/parameters/events_dfl_poll_msecs
From udevil Homepage.

Friday, May 9, 2014

A look at Gnome 3.12

I would have liked to have an in depth look at Gnome 3.12, but unfortunately the Live CD I tried kept causing kernel panics every time I tried to launch an application. Here are a couple of screenshots I was able to take:

What I can say about it is that it looks beautiful, by which I mean the GUI of Gnome applications, the theme, the icons and the desktop, and it looks contemporary- of the 21st century rather than the 20th.

The Activities overview seems to open quickly. I tried an install of Gnome 3 recently in Fedora and found that there was a significant lag in opening the  Activities overview, admittedly on a now-quite-old laptop. I hope this is due to improvements in the compositing engine that might make Gnome more usable for me.

I've seen several people who wrote that they hated Gnome 3 say now that they use it and love it, so I suppose it's a bit ironic that I said I loved it from the start but don't now actually use it. Apart from the performance issue, another issue for me is non-Gnome applications. For example, I use Liferea a lot, but its notifications don't work natively with Gnome and look terrible; in XFCE however, it's fine.

Gnome 3.12 is in Debian Testing. I am tempted to try installing it, because it looks so good, and to see if any of my problems with Gnome 3 have gone, but my current installation of XFCE on Debian Testing is just so usable and stable that I'm reluctant to wipe it.

Thursday, March 27, 2014

Welcome to GNOME 3.12

Gnome 3.12 is out. You can try it out here. Somebody has already done so and posted a video (with a great soundtrack) here. I'll be doing so myself soon.

Tuesday, December 31, 2013

XFCE annoyances

XFCE is a great Linux desktop and ideal for replacing Windows XP on older computers (security updates are of course gong to end for XP next year, so there's no time like the present for trying Linux on XP machines). I've been using it for about six months on this 2005 laptop, as well as on a 2003 laptop. XFCE is noticeably less taxing on the more modern laptop than Gnome 3.10, which I tried recently in the Fedora 20 beta, especially when switching quickly between different applications.

XFCE shares the same desktop paradigm as Windows XP (panel, menus, window buttons etc), so it's an easy switch to make, except for a few annoyances which may put off new users. I'm going to detail theses annoyances and how to get round them here.

Problem panels

After installing XFCE and logging in to your account, you are prompted to set up a panel. However, if you don't save the session after logging off, the next time you log on, you will not see any panels. You can get them back by right clicking on the desktop and going to Applications>Settings>Panel. However, you may see a popup window with the following error message as described on the Arch Linux forum:
The panel cannot be edited while running in kiosk mode.
Solution: Drop out of XFCE with Ctrl + Alt + F1, navigated to ~/.cache/sessions/ and delete the contents with the following command:
rm -rf *
Restart, log in to XFCE, set up panels as required and save the session on exit to see your panels appear at next log on.

Unwanted saved sessions

Having saved your session to save your panels, you may decide that you don't want to have every application you had open at shutdown reappear when you next log on. The solution to this is to close all applications, log off saving the minimal session, log back on and disable saved sessions.

However, you may be puzzled to find that applications are still reopening at logon.

Solution: be aware that only the logout GUI respects the preference to not save sessions. (See this post on the XFCE forum.) The Action Buttons panel plugin seems to use a shutdown method that does not respect session preferences, so if you're wondering why applications autostart when you've chosen not to autosave sessions, Action Buttons may be the culprit.

Sunday, December 22, 2013

Debian Sources List Generator

Ever wondered what your sources should be in Debian? Debian Sources List Generator will generate a sources list for you.