Your Linux Self-Help Desk. A selection of mostly Linux related tutorials, howtos, fixes, news and more.
KDE 4.1 in Windows XP SP3
After that it was amazing to see the KDE applications work pretty well natively under windows. And some KDE software is just really, really good and better than anything else you can get to run on windows.
Opera Link Disaster
Well, what was I going to do?
I tried to recover what was left. Many folders and files were just randomly spread across the Opera link directory where I at first couldn't find them, instead of deleted.
Then I tried to ease, but online editing is hardly possible. Trying to sync really deleted most of the bookmarks this time. At least there wasn't as much to sift through.
So I put everything in the trash and picked out the good stuff, put it into new folder and basically started over. Now I will backup my bookmarks and pray this won't happen again.
You really need to work on that sync code, guys at Opera!
The Incredible Dangers of the Buggy Opera Link
The problem is only that it's written so incredibly bad, that it's extremely dangerous to use. You must definitely make a backup of all your bookmarks before even thinking about using Opera link.
I had a database of about 550 bookmarks. They were neatly organized in the last few months and of course many were new. Because in the past Opera link often duplicated my bookmark folders, I created a new account to sync to.
The problem is I was too damn stupid to make a backup before using Opera link. And now the worst possible thing happened.
Opera did not use the newly created account I told it to use. It did not backup my bookmarks. It "synced" to the old account. It deleted all my bookmarks from the last 6 months forever. And it replaced them with the mess that had existed before.
I'm indefinitely frustrated right now, more than I have been in a very, very, very long time.
I think I will switch my browser.
Understanding Directory Rights in Linux
If you use ls -l it would display for example drwx--srwt someuser somegroup(...).
The first letter of the permission string is always d and stands for directory. Than come the letters for the user (rwx), the group (--s) and others, meaning everyone who is not the user of the group (rwt).
r--
If you have only reading rights you can do nothing (chmod a+r-wx mydir). If you're the owner you can list the contents it seems.
r-x
If you have reading and execute rights (chmod a-w+rx), you can see cd into the directory and list its files. But you can not create any files.
-w-
If you have only writing rights, you can not do anything with it.
-wx
If you have writing and execute rights, you can create new files, but not list the directory's contents. But you can still access the files, if you know their name and have permissions for that.
rws (with x) or rwS (without x)
If the directory's group permission is set to super (chmod g+s), new files have are owned by the same group as the directory.
rwt or rwT(without x)
If the text bit is set (chmod o+t), files in the directory can only be deleted by their owner, not the group. But they can still be overwritten, if the files permissions allow that. So it's no real protection.
This means that usually there's little sense in a directory that's r-- or -w-, as that let's you do hardly anything. You should usually set the directory to r-x, -wx or rwx.
Important: A user needs to have at least execute (x) rights to all directories above the directory in order to be able to do anything in it.
Be aware that the handling is usually on the careful side, so if you are the user and your permissions are --- but the group's permissions are rwx and you're in the group as well, you won't be able to access the file or directory. Because the more restrictive rights for the user will be used in favour of the permissions of the group you are in.
Also notice that in the example commands, e.g. chmod a+r-wx, I usually set the permissions for a, which stands for all and means user, group and others. This is just to make sure you can reproduce what I have written here. Of course you should carefully select what the rights for the owner(o), the group(g) and the others(o) should be: E.g. chmod u=rwx g=rx o-rwx mydir.
Also check out Wikipedia on file permissions as well as these articles by LinuxExposed for files and directories.
The Internet
I just wanted to try out something I found on the DVD of my computer magazine. I don't know why, but I just went to the website to download it. The problem is just that I'm in Australia and the download limit for this month is already exceeded and thus the bandwidth throttled to 6kb/s.
And after I had downloaded half of the file from the Internet it occured to me: Why not copy it from the DVD? And so I did. Crazy how you can get accustomized to downloading everything online...
Pc speaker as sound card
mplayer -ao alsa:device=hw=pcsp
The sound is of course pretty bad, but also amazingly good when you think about the fact that it's only made beeping. ;-)
Undelete Files on the ext3 filesystem - Finally!
The funny part is that many people are not yet aware of this and you may thus still make interesting findings in partition images, e.g. the popular VMware images.
Check out the article at Linux.com for more.
Fork KDE?!
Now let's see if the people bringing the complaints will deliver this or just keep shouting and complaining about it.
Look at the well written plasma libraries and you will know what I mean. KDE4 is a huge step and it's just amazing I could install the great vocabulary trainer parley unter windows with just a few clicks. This means you write your application with the comfort of KDE4 but you can use it under Windows, OS X, Linux and possibly other operating systems.
Check out this groklaw article for more.
Plasma Clocks after Suspend to Ram
The answer to life, the universe and everything
"answer to life, the universe and everything"
and you shall get it. More, as always, on Wikipedia.
Many Applets in KDE Playground trunk are broken
I especially like wifi-signal-strenght: Easy but nice and rather pretty. Get it with
svn co svn://anonsvn.kde.org/home/kde/trunk/playground/base/plasma/applets/wifi-signal-strength
And compile it with:
cd wifi-signal-strength
mkdir build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=/usr/lib/kde4/
make
You may have to replace with PREFIX with the one from your distribution.
Run Applications Faster in Wine
env WINEDEBUG=-all wine
it's a bit faster, because the debugging is turned off.
Intel Wireless Card not working in Ubuntu 8.04
sudo /etc/init.d/hal restart
This might fix that wireless networks don't show up as well as other problems. Try the key combination for enabling/disabling the wireless card in your notebook again afterwards.
NX Remote Control Software.
It only needs one free port - the SSH port 22. And you can get your free server for Linux or Solaris(limited to two users). The two users which can use NX are chosen when you first connect as a certain user. If you want to free one user slot, just delele the user from NX:
/usr/NX/bin/nxserver --userdel user123
Another cool thing: Instead of the whole desktop environment you can also just run a single program. That makes it really easy to run a Linux program in a Windows environment. It supports printing over cups and has (rudimentary) sound and video support.
And this is not paid advertisement, I actually really like the software. And I think it's great the small company publish the library under the GPL. Of course you have to pay for enterprise level tools. But hey, they got to make money as well. ;)
µTorrent with Wine under Linux
Here's a little script to let you pass .torrent files comfortably over command line. I've got the same type of script for WordViewer and other software. Hopefully this will sometime soon by handled by wine directly.
#!/bin/sh
WINE="env WINEDEBUG=-all wine"
UTORRENT="C:\Programme\uTorrent\uTorrent.exe"
if [ "$@" ]; then arg="z:`echo $@ | sed -e 's/\//\\\\/g'`"; fi
echo $arg > ~/logs/tmp
if [ "$@" ];
then
$WINE "$UTORRENT" "$arg" >> /dev/null 2>> /dev/null &
else
$WINE "$UTORRENT" >> /dev/null 2>> /dev/null &
fi
Wine is called without debugging to save more resources. The argument is converted to a pathname that wine can handle better ("/" are converted to "\"). You probably need to adjust the path where uTorrent is saved.
Fork KDE?!
Practical-tech.com suggests KDE should be forked because he doesn't like the KDE4.1 prerelease so far. It's easy to come along, look at a prerelease and say: "Nah, don't like it." But you must be pretty crazy to go further and say: If I don't like it, noone will. So it should be forked.
It's funny because the things he criticizes most are the ones I cherish most in KDE 4.1.