Cron دایمونی (Daemonها مانند سرویس ها در سیستم عامل ویندوز است) است که برای زمان بندی کارها در گنو/لینوکس استفاده می شود. هر کاربر در گنو/لینوکس دارای یک فایل به نام crontab است که دایمون Cron برنامه هایی که در فایل های crontab قرار دارند را بر اساس زمان بندی آن ها اجرا می کند.

برای ایجاد فایل crontab به راهنمای ویکی در این جا مراجعه کنید.

برنامه هایی که شما می خواهید اجرا کنید به دو صورت هستند:

1. برنامه هایی که دارای محیط گرافیکی کاربر هستند (GUI) و نیاز به تعامل با سرویس دهنده پنجره X هستند مانند مرورگر Firefox
2. برنامه هایی که بدون GUI هستند که این برنامه ها خروجی و ورودی آن ها در پوسته خط فرمان است و برای اجرا شدن نیازی به تعامل با سرویس دهنده پنجره X ندارند. مانند برنامه ls یا GPG

برنامه هایی که در دسته دوم قرار می گیرند بدون هیچ مشکلی به وسیله Cron اجرا می گردند. اما برنامه های دستهٔ اول که دارای GUI هستند فقط با نوشتن دستور مورد نظر اجرا نخواهند شد. قبل از دستور باید به سرویس دهنده X بگویید که برنامه در کدام صفحه نمایش برای شما اجرا شود. برای این منظور قبل از دستور مورد نظر از env DISPLAY=:0 استفاده می کنیم. به عنوان مثال برای اجرای برنامه gedit در ساعت 10:25 هر روز صبح در فایل crontab دستور زیر را وارد می کنیم:

25 10 * * * env DISPLAY=:0 /usr/bin/gedit

DISPLAY=:0 به Cron می گوید که برنامه در صفحه جاری (desktop) اجرا شود.

و اگر دارای چندین صفحه نمایش هستید از دستور زیر استفاده می کنیم:

25 10 * * * env DISPLAY=:0.0 /usr/bin/gedit

DISPLAY=:0.0 به Cron می گوید که برنامه در صفحه نمایش اول و در صفحه جاری اجرا شود.

توجه: در اوبونتوی 9.10 (کارمیک) شما باید X ACL را برای localhost فعال کنید. برای این منظور از دستور زیر استفاده می کنیم:

xhost +local:

این دستور حتما باید قبل از اجرا شدن یک برنامه GUI به وسیله Cron اجرا شود. شما می توانید این دستور را در قسمت Startup Application قرار دهید تا هنگام بوت شدن سیستم اجرا شود.

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El equipo de X.org ha hecho su X Server 1.7.0 disponible para descargar. X.org 7.5 sera el siguiente a seguir, según una nueva, orden de estrategia de liberación.

El nuevo servidor X, segun cuenta Pedro Hutterer, dispondra del apoyo de dos cursores, por primera vez se permitira el apoyo de múltiples cursores simultáneos, que en teoría debería permitir el acceso a más de un usuario a la misma PC, incluso para juegos que utilizan esta característica. También por primera vez X Server 1.7.0 se basará en Xquartz para proporcionar un servidor estable para Mac OS X basado en el código fuente original de X Server.

Esto es especialmente util cuando se requiere jugar con dos mouse ya que se dispondra de dos cursores en pantalla muy util para los juegos de disparos.

Fuente: linux-magazine

Happy-Word

In einem älteren Beitrag hatte ich mich ja schon mal über den aktuellen Zustand der Intel Treiber unter Linux ausgelassen und bisher hat sich anscheinend auch nicht wirklich viel getan. Vor kurzem bin ich aber auf ein interessantes Paket in den Arch Linux repos gestoßen, welches wohl eine ältere Version (2.3.2-3) der Intel Treiber enthällt. Anscheinend hat sich wirklich jemand die Mühe gemacht und diesen Treiber an neuere X.org Versionen angepasst.

Ausprobiert habe ich ihn bis jetzt noch nicht, weil auf meinem Netbook momentan Debian läuft. Auf einen wirklichen Performance-Schub darf man aber nicht hoffen, der Treiber unterstützt wegen den neuen X.org Versionen wohl kein XAA. Ich könnte mir aber gut vorstellen, dass er so einige Stabilitätsprobleme lösen könnte. Garantieren kann ich aber für nichts – die alten Treiber wurden schließlich nie ausgiebig in Kombination mit neueren X.org Versionen getestet!

Recently I decided to get out the old GTA2 Laptop again. Why GTA2? Because that was its killer application, as it only features a 600 Mhz Intel Celeron, some on-board graphics card and 64 MB of RAM. This game runs pretty well while being very much fun, especially the LAN mode is just awesome. If you never played GTA2 yet, here’s a multiplayer gameplay video I just googled up. Also the game became freeware, so if you like it download it!

But let’s get to the point of the article. I have always played with the thought of installing (any) Linux on this notebook, until yesterday it was running a very nlited Windows XP.  So I finally decided to throw that off the about 5 GB harddrive and give arch a shot. Why did I choose Arch and not lets say Debian? The later one compiles x86 packages for i386, but archlinux compiles to i686, which is less backward compatible, but a bit faster. Plus the other reasons why I just love archlinux – simple configuration, pacman and yaourt, aur and so on.

While downloading the lastest snapshot for i686, I browsed a bit around and came across this thread from which I used their suggestions to add lowmem to the kernel line as well as setting ramdisk to 20% (also kernel line in grub). Then /arch/setup worked out pretty good, just like any installation. It was a bit slower of course, but I didn’t expect it to behave different.

Suprisingly WLAN actually worked with ndiswrapper, I was not sure about that at all. This laptop has a T-Com Sinus 154 Card, I took the windows driver from the installation CD. The next not-so-clear-thing was setting up xorg without nvidia (I’m used to do it with that), but after I found hwd, it worked out fine.

lxpanel displays the CPU usage at the bottom right corner

To get decent performance, only lightweight and fast software would work. As WM I chose openbox with the lxpanel. The browser with the best performance after text browsers is propably dillo. But dillo can’t even display common websites like wikipedia and google right, because its CSS implementation has just started. Even worse, javascript does not work at all, so sadly half the web does not work. If you just want to do some quick research, it is enough though, so I kept it installed. Firefox was slow as hell, just the experience I had using it with windows XP. Because of that I tried some alternative browsers. Chromium (the opensource project behind Google Chrome without the spyware) just segfaulted, so I tried the closed source Opera (10). Yaourt -Ss opera lead me to opera-snapshot from the archlinuxfr repository, which was actually pretty fast. In every other case, it would have been Firefox. But as this was just a matter of speed, Opera took the cake.

QMPDClient open

Other software I installed is mpd, mpc and for the first time QMPDClient as GUI. Mpd is very lightweight and can be used without a X server, just like unix tools should behave. I chose the said graphical user interface, because it is not written in script-languages like python or perl, but in c++ which not only has less dependencies, but also brings more speed. In fact, I have nothing python or perl related installed on this machine.

desktop pc: copying music from within amarok to my laptop

Another pick was OpenSSH and SSHFS over nfs and samba. Why? Because nfs did not work at all and samba plus its dependencies was about 100 megabytes. When I mounted my laptop’s music folder on my desktop computer, I was able to fill it from within amarok via drag and drop, just like any mp3 player, which is quite useful

Other applications I installed and tested were pidgin, codeblocks and lbreakout2. For pidgin, I think BitlBee plus something like xchat would be the better choice, but I have not tried that yet. It was usable though, as well as codeblocks and lbreakout2 were. What I did not try yet is GTA2 (with wine), but I will likely do that.

No desktop icons, no wallpaper

Software I did not install on purpose: A program that displays a wallpaper and/or desktop icons and a file manager. These are just too wasteful for that little system.

Update: As expected, GTA2 is not playable at all. The wine-layer is just slowing it down too much, and while epsxe offers more tweaking, it is not faster. On the other hand, I’ve got bitlbee with the otr patch running. Bitlbee is a fake IRC server which displays contacts from other IM networks that all IRC programs can connect to. Since I found out that Opera has an integrated IRC client, I don’t even need another program and so I removed pidgin.

Furthermore I did not mention the usage of the Vorbis audio codec yet, which is better known by its file extension ogg. Because they are so small, you can easily fit much music on such a tiny harddrive. Oh and I compile most aur packages from my arch32 environment on my desktop pc. That saves much time.

So in conclusion there’s pretty much you can do with a low-end machine like this. The most exciting feature for me is ssh and ssh-fs. GTA2 does not work anymore, but I have played the single player mode almost through anyway. LBreakout2 works fine and without making the cooler get very loud, like GTA2 used to. Plus now I just have a fully running linux with all its nice CL tools

Got a new Samsung 22″ 1920×1080 monitor and the default resolution being shown was 1280×800. Now with 8.04 I used to do dpkg-reconfigure xserver-xorg and it would redo the X11 configuration.

In Jaunty, the above command just configures the keyboard setting. In order to get the monitor to work with the correct resolution do

$ xrandr

This would probe the monitor and display the resolutions, then do the following

$ xrandr --output VGA --auto --above LVDS

The past days I have been on Rocco del Schlacko 2009, a festival in Germany with four of my favorite bands: Anti-Flag, Rise Against, Zebrahead and Farin Urlaub Racing Team (the last one sings in German). It was really fantastic, but I won’t write too much in English about it, because I think the information will be more useful in German plus it makes it easier for me to comment ADI64, who already blogged a whole article about it in that language. So expect another post on that topic soon.

In other news, I just ran a  yaourt -Syu today which finally brought a fixed evdev and made my keyboard work as usually again. I’ve had serveral issues, the most annoying one caused my X-server to zap randomly (I have Zap activated, because it’s useful to kill my gaming X-Server), also characters appeared twice or three times by pressing the key only once and the scroll lock LED toggled by pressing random keys. Weird shit!

I woke up this morning in a not-so-good mood and thought I had enough of a hardware problem I had on my PC that had been bugging me for about two weeks. I then started troubleshooting my hardware and after pulling out my video card and putting it back in, everything was miraculously solved. So it seemed to me like today was the day for miracle fixes and I addressed an extremely weird problem that came up on my laptop since probably last Sunday:

I was working on a Qt project that uses OpenGL (I’ll soon post about it) and I left it working relatively fine on Sunday. While I worked on that project, I had an ongoing update on Gentoo’s world of just 17 packages, none of them sensitive to the system. I also changed my X Server configuration to something less sophisticated because I had done some changes trying to get Compiz working on my radeon driver and I thought those were messing up a part of my program… yet I forgot to restart X to test those changes. Nevertheless, everything was working ok when I shut down my laptop that night.

Yesterday I was going to do some more work on that project and I tried to run a modified version of it and it “failed with an unexpected error” as my Qt Creator said. I tried it from the console, and it died with a Segmentation Fault. I removed all changes and it still died with a Segmentation Fault. I went to the original version of the project (I was working on a separate folder to do those changes) and I ran the original version, and it died with a Segfault too. I then ran it on GDB and observed that the program was dying on a call to glxWaitX() which was done internally by libQtGL to libGL. I was really puzzled but after double checking the list of installed packages on Sunday’s update and reasuring nothing could have changed my OpenGL implementation, I remembered that untested change on my X Server. So I reconfigured my X Server with the defaults (using xservercf), restarted X and tried again… nothing.

Today I Googled on Segfaults on glxWaitX() and I realized people were having the exact same problem on Mythtv on Ubuntu, and many other Qt4 + OpenGL programs on Fedora, all bugs report were recent: between April and May of this year. One of the guys at the Fedora bug report said the problem was specific to Qt and OpenGL, and that it was solved on SVN versions of the Mesa library. It didn’t make any sense to me: I had not changed anything on my Mesa configuration recently, so I kept trying workarounds reinstalling the version I had of Mesa library (7.3-r1) and libDRM (that’s NOT Digital Rights Management!) and nothing helped. I then gave in on my research and opted for the easy fix: I bumped up a version of Mesa an libDRM and emerged those new packages… and everything was miraculously working back again.

I’ll probably never know what happened there, which actually sucks because that’s one of the reasons I use Gentoo, because it lets you get down and dirty with the system to understand what can go wrong and how to fix it. But the good thing is I can now go back to my important project. I hope to read someone’s comments here telling me what was that all about, and I also hope this post helps some other Gentoo (or any other distro whatsoever) user experiencing the same problems. Happy Hacking!

I’ve wanted to play/pause music with Amarok while playing a game on a second X-Server. The trick is to use

DISPLAY=:0 dcop [...]

instead of just dcop in combination with software like xbindkeys, so that dcop can find amarok (which is running on the first X-Server in my case).

In questo momento sto scrivendo dal mio pc fisso, sul quale di recente ho reinstallato Ubuntu Pure remix. Ho un monitor CRT da 17 pollici, che seppur vissuto fa ancora benissimo il suo lavoro, tuttavia supporta anche risoluzioni “enormi” per la sua ampiezza.

Ubuntu in automatico infatti mi fa partire lo schermo a una risoluzione superiore rispetto a 1024×768, che uso di solito. Purtroppo come sapete il file xorg.conf non è molto “loquace”, è quasi tutto auto-configurato. Per questo ho dovuto cercare in internet come fare per forzare la risoluzione.

Non è una faccenda poi così difficile (il fatto che il gestore delle impostazioni video di Nvidia non riesca a elaborare il file la rende solo scomoda). Vi riporto la procedura per reimpostare la risoluzione a livello di sistema e anche la frequenza di aggiornamento (sui CRT specialmente fa la differenza, anche per la nitidezza).

Per prima cosa aprite per la modifica il file:

sudo gedit /etc/X11/xorg.conf

Dopodiché all’interno della sezione Screen inserite questa sottosezione:

SubSection "Display"
Depth 24
Modes "1024x768_70" "800x600" "640x480"
EndSubSection

Vedete la modalità a 1024×768? Contiene anche indicata la frequenza di aggiornamento, separata dall’underscore “_”. Salvate ed uscite.

Facendo il logout vedrete la risoluzione tornare al suo posto. Non è una guida enorme, ma penso torni utile a chi si trova con una risoluzione immensa e minuscola.

While Installation of NVIDIA Graphic Drivers the system asks you to stop X Server!! This can be done with following steps…

1. Press CTRL-ALT-F1

2. Give your login details (viz. username and password)

3. Now to stop X Server use following command

sudo /etc/init.d/gdm stop

4. Proceed your installation of required driver package.

ex: sudo sh [deb package name]
and follow the instructions.

5. Now start your X Server Again using following commands

sudo /etc/init.d/gdm stop

You are done with the driver installation

About the only problem I have with my OpenSUSE 11.1 on my desktop PC at work is the ATI graphic card configuration. Each time I upgrade the kernel I have to rebuild the module again, so I enclose here a list of steps that seem to work fine. I have taken these from pongaunagujeronegroensuvida.

1. Obtain the latest ATI drivers, some large file named “ati-driver-installer-9.2-x86.x86_64.run” or similarly.
2. Go to text mode (su -; init 3).
3. Run it as a superuser (su – ; sh ati-driver… etc ), select direct install.
4. Run aticonfig –initial -f
5. Try aticonfig –overlay-type=Xv, although it may do nothing.
6. Run sax2 -r -m 0=fglrx. Hopefully, it will present a X valid config screen; say “OK”.
7. Reboot normaly.
8. Each time the kernel is upgraded: reboot in secure mode, the X server will fail, but press crtl+atl+F1, go to step 3.

If you ever want to see what Linux was like before they had GNOME or KDE (or any other desktop environment for that matter) here are some simple steps to (try) to bring down the X-Server. Due to the possible different configuration of your X Server, I make no promise to this actually working.

If you want to restart the X-Server, on most systems at least, do Ctrl+Alt+Backspace. But this won’t keep it down. It will merely restart the X Server, useful if your computer isn’t responding. The way I bring it down is the command (be sure to either be logged in as root or to use sudo) :

su
shutdown now

If you don’t specify any options:

[...The system is brought down into maintenance (single-user) mode by default...] (taken from shutdown –help)

Single user mode is, Linux with no X-Server. If you try to use a program like Gedit or Firefox, you will most likely get a GTK error.

I really don’t recommend doing this, but if you want to see, be my guest. Personally, If you want to do something really cool install Elinks and run it in maintenance mode. It will amazing how much you can do from the terminal!

Weil oft danach gefragt wird und ich keine Lust habe, immer alles neu zu schreiben, gibts hier eine kleine Anleitung. Ich benutze übrigens nicht die Treiber aus den repos, sondern immer den Aktuellsten. Der Nachteil ist, dass man nach jedem größeren Kernelupdate den Treiber neu kompilieren muss. Die Features der neuen Treiber möchte ich aber jedenfalls nicht mehr missen.

Gerade die Treiber aus der 180er Serie haben nämlich eine deutlich bessere 2D-Beschleunigung mit Karten, die auf eine G80 GPU oder neuer setzen. Diese Karten müssen die 2D-Beschleunigung über die Shader(?) ausführen und das klappt mit den 170er nur über zusätzliche Befehle, die leider auch nicht die Performance der neuen Treiber erreichen. Vergleichswerte mit gtkperf kann man in diesem thread finden.

Bevor es ans Installieren geht, braucht man natürlich den richtigen Treiber. Nvidia unterstützt momentan noch alle Grafikkarten ab den Geforce 6 Modellen mit den normalen Treibern, alle darunter werden durch sogenannte Legacy Releases versorgt. Finden kann man diese Treiber entweder über die Nvidia homepage oder im nvnews forum.

Um die Treiber kompilieren zu können, benötigt man aber noch einige Pakete.

aptitude update && aptitude install build-essential linux-headers-`uname -r`

Dieser Befehl bringt die Datenbank von apt auf den neuesten Stand und installiert das Metapackage build-essential, das schon die meisten Kompilierwerkzeuge mitbringt, sowie die kernel-headers.

Leider lässt sich der Treiber nicht installieren, solange eine grafische Oberfläche läuft. Daher muss man mit STRG+ALT+F1 auf eine Konsole wechseln und meldet sich als “root” an. Den X-Server kann man wieder mit STRG+ALT+F7 erreichen.

Wie man die grafische Oberfläche schließt, hängt vom verwendeten login manager ab. XFCE und Gnome benutzen GDM, wenn man die Standardinstallation von Debian benutzt, KDE dagegen verwendet KDM. Im Grunde muss man aber nur gdm gegen kdm bzw. xdm im Befehl austauschen.

Schließen:
/etc/init.d/gdm stop

Um ihn wieder zu starten:
/etc/init.d/gdm start

Wenn die grafische Oberfläche geschlossen wurde, kann der Installer mit sh aufgerufen werden.

sh /hier/liegt/der/treiber

Die Warnungen, dass die GCC Version nicht passt, kann man einfach ignorieren. Eine neue xorg.conf sollte man durch nvidia-xconfig aber nicht anlegen lassen, weil dadurch unter anderem ein falsches Tastaturlayout in die xorg.conf geschrieben wird. Alternativ kann man eine Datei mit dem Befehl X -Configure in /root erzeugen. Mit nano kann die alte xorg.conf auch ganz einfach um den Eintrag für den Treiber erweitert werden.

nano /etc/X11/xorg.conf

Nun schreibt man einfach in die Section “Device” noch zusätzlich Driver "nvidia", speichert mit STRG+O und schließt nano mit STRG+X. Der login manager kann jetzt wieder gestartet werden.

Fertig

Wie vielleicht einige von euch schon mitbekommen haben, setzen die neuen Versionen von Ubuntu, OpenSUSE sowie Fedora auf eine neue Tastenkombination, um den X-Server neu zu starten. Strg-Alt-Backspace wird also zukünftig nicht mehr funktionieren und durch Alt-Druck-K ersetzt.

Die Änderung erscheint zwar auf den ersten Blick nicht besonders spannend, der clou ist aber, dass nun auch vermeintlich abgestürzte X-Server beendet werden können.

Tja, darauf muss man aber auch erst einmal kommen. Hatte mich schon gewundert, warum das neue Xubuntu auf die alte Tastenkombination nicht mehr reagiert

Instalação do driver NVIDIA no Ubuntu

Nunca fui fã do desktop Linux. E olha que faz tempo que utilizo Linux em meus servidores. Tudo começou com o Conectiva Guarani (versão 3 de 1998). Nunca me adaptei ao KDE e nem ao Gnome. Sempre instalei, mas nunca passei mais de um mês utilizando. Tentei também icewm e Fluxbox, mas nunca me adaptava… De um mês pra cá recomecei a utilizar o Gnome e por incrível que pareça me apaixonei. Ainda apanho com a interface, pois minha praia é programação e servidores, então não tenho costume de procurar o ícone correto para uma determinada ação… mas vamos tocando…

Como o Gnome me empolgou bastante, migrei todo meu desktop pra ele e logo de cara surgiu um desafio: como utilizar minhas placas GeForce 7200 GS e GeForce 8400 GS para fazer dual vídeo?

Dual vídeo, para quem não conhece, é fazer com que seja possível utilizar dois monitores para ampliar a área de trabalho. Muito bom para quem programa (bom também para quem trabalha com gráficos), pois posso abrir o gerenciador de banco de dados em uma área e a IDE de desenvolvimento em outra.

Procurei então como instalar minha GeForce 7200 GS no Ubuntu Jaunty (Ubuntu 9.04) e vi que existe na área de Sistema / Administração o utilitário de drivers, porém, pelo menos pra mim, apresentou vários problemas fazendo com que o Jockey (nome do utilitário) parasse de funcionar várias vezes sem conseguir instalar o driver. Então fui ao site da NVIDIA e baixei o driver e fiz a instalação manualmente que mostro abaixo:

Primeiro, vamos baixar o driver direto do site da NVIDIA. Então basta acessar http://www.nvidia.com.br/Download/index.aspx?lang=br e escolher o tipo do produto, série e família. Não precisa escolher o sistema operacional, pois o próprio site já identifica o Linux.

Após baixar o driver, basta sair do gerenciador de janelas, que no meu caso é o Gnome. Para isso abra o aplicativo Terminal que está no menu Acessórios dentro de Aplicativos e digite o comando abaixo:

$ sudo /etc/init.d/gdm stop

Pronto, agora que saímos do Gnome (ou de outro gerenciador de janelas), podemos executar o instalador com o comando:

$ sudo sh NVIDIA-Linux-x86-180.51-pkg1.run

E começa a instalação… a primeira coisa a fazer é aceitar a licença de uso. Os próximos passos, pelo menos no meu caso, foram simples, basicamente lia a informação e selecionava ok ou avançar. As informações eram referentes ao Kernel precompilado, a necessidade de adicionar módulo ao Kernel, porém isso tudo o driver fez sozinho.

Bulding kernel module

Por fim o instalador informou que inseriu o módulo no Kernel e que a instalação estava finalizada.

Então agora é voltar ao Gnome e configurar o driver. Para iniciar o Gnome digite o comando abaixo:

$ sudo /etc/init.d/gdm start

Voltamos ao Gnome, porém com o driver funcionando. Para finalizar a configuração e habilitar o segundo monitor, basta acessar o menu Sistema, depois Administração e você verá o item NVIDIA X server settings.

NVIDIA X server settings

Dentro do aplicativo, basta clicar na opção X Server Display Configuration. Você verá que seu segundo monitor não está habilitado, então clique sobre ele e depois no botão Enable. Pronto. Agora seu Ubuntu Jaunty já está funcionando com dois monitores.

Após utilizar por um tempo, a funcionalidade de efeitos visuais extras simplesmente parou! Para resolver qualquer tipo de problema no funcionamento do driver NVIDIA, basta utilizar o comando abaixo:

# nvidia-xconfig

Meu próximo passo no desktop é fazer um deskmod bem legalzinho.

Fontes e Referências:

• NVIDIA
• Fórum Ubuntu

This article is also your answer to: How to access a Linux system GUI remotely via SSH from Windows?

Accessing the GUI in Linux remotely from another Linux box via SSH is very simple. But if you are at your workplace (where you most probably run windows) and want to access the Linux GUI at your Home from your office, via Windows, then you need to configure and set up a few softwares and tweaks which will do the job for you. For setting the entire thing up you need Three (3) things to be installed on your computer:

Xming X Server for Windows, Xming Fonts, PUTTY – SSH Client for Windows.

The Xming server is a 2.5 MB download and the Xming Fonts package is a ~35 MB Download. The Putty client is an executable, you just need to download and run it. Now follow these steps. We have included a screencast at the end so that you can speed up the installation process.

1) Goto the program properties of Xming (right click on the Xming icon and select properties). In the target field, add -ac to the end of the target string. This switch sets the Xming server to allow anonymous connections. Now Start the Xming X server. Once it starts, you will see a X icon in the system tray.

2) Now open the Putty Client. From the Menu on the left hand side, select Connection > SSH >X11. Check Enable X11 Forwarding. Enter your X Display location. This is generally localhost:O.O (if your remote desktop on tty7 – the GUI). Now goto Session and key in the ip address of your rmote server and the port on which the remote SSHD server is listening (22 by default). Make sure you have started the Xming X Server as described in step no.1. Now start the SSH session by clicking on Open.

3) In the terminal that opens, type a command such as xterm or xclock or try to launch any GUI application. Wait for a few seconds and your remote GUI will start. Thus you have now successfully forwarded X11 Session to windows over SSH!!

Here is the screencast, that will make things much easier for you: http://blip.tv/file/1827992/

Related: How to securely transfer files between two computers in Linux?

Technorati Tags: X11, forward, session, linux, windows, xming

I like my EeePC 901, though the missing navigation keys hit me a bit, and getting a pipe symbol (|) with one hand is wrist-flipping (AltGr+Function+Y [on a German keyboard]). I knew I had to fix that, and now I’ve done it.

As a solution, I set up some alternative keys to trigger:

• lesser than
• greater than
• pipe
• Home
• End
• Prev Page/Page Up
• Next Page/Page Down

Note: This article is going to be a bit more long. Hence, if you want, you can just skip to the howto. Oh, and by the way, the solution provided is for the X server, not for Windows.

(CC) BY-NC-SA I'mNannie / Flickr; example EeePC keyboard (en)

For the navigation keys, initially I thought I could just reuse the given navigation keys Up/Down/Left/Right by hitting them while holding down AltGr. Though, that didn’t work, so I had to find some new keys to use. As I am a right-handed person and as I don’t want to occupy the other hand for navigational tasks too, the right side of the keyboard is the only choice.

In that area we’ve got the AltGr key available as a modifier. Also, there is a mouse menu key — pretty pointless as the big touchpad is right next to it. So, alternatively, I could use that mouse key as another modifier key. But it turned out that didn’t work, so I have AltGr as the only modifier available.
 

Since I couldn’t reuse the menu key in any other obvious beneficial way, I decided to make it become Page Down. Of the missing navigational keys, Page Down is the most important one since on web pages and other large documents you start at the top and want down, not upwards. In browsers, usually the spacebar works also, but in editors hitting the spacebar gives you a space, not a Page Down.

Next, Page Up, since Page Down is rather silly. So what key to use? — I picked ‘.’ (period) since its almost straight North of the menu key.

Since there’s no other use for the menu key, I made the menu key be Page Down without any modifier to be held down, though to stay able to use the period as usual, to make it be Page Up, it must be used together with the chosen modifier, AltGr.
 

On trying out AltGr as a navigational modifier, I learned that it’s cruical to be able to use the key-to-be-modified with the middle finger, and that conveniently. So, choice what to use for Home and End became quite restricted.

I selected L and the character second-right to it, ‘Ä’ on a German keyboard. — I left the one-key gap in between since the keys out there in the periphery are a bit more slim, and the L/Ö alternative felt not as convenient as using L and Ä.
 

On the issue about the lesser-than and greater-than symbols as well as the pipe one, I chose to keep them in the bottom left corner of the keyboard. In German layout, the bottom left key is Y.

Originally, to get a Pipe, you need to press AltGr-Function-Y. Doing this one-handedly requires quite a bit of training, but still you often will achieve AltGr-Y only, which gives you some angle-bracket like quotation mark.

Also, to get a greater-than character, you need to perform a similar bit of keyboard artistic — AltGr-Shift-Y.

That’s a bit inconvenient. Instead, I decided to untangle those four characters a bit: I want a two-keys combination at max. That is: AltGr+Y gives lesser-than, AltGr+X be greater-than. And for purpose of convenience I put the pipe North of X and Y: AltGr+S gives Pipe. Perfect.
 

Sidenote: The key next to the backspace, on a German keyboard layout is rather pointless: Originally, it features the single quotation mark and the backtick, though there’s another key nearby, featuring the very single quotation mark and the number sign — and AltGr gives you the backtick too. As AltGr+# or Shift+’ is the same number of keystrokes, alternatively, you could dump the key next to the backspace completely and put lesser-/greater-than and pipe there. — I did not so because I learned about AltGr+# only after I was done with configuring, and you might also want to keep the usual keys (like single quotation mark/backtick) untouched.
 

How To Do It

Here is how I applied the modifications:

First, XModMap is the tool of choice.

On the console, I retrieved the current, i.e. system-given, settings for my keyboard by xmodmap -pke. I immediately stored that output to ~/.xmodmaprc where it will be read from, each time I’ll re-login: $ xmodmap -pke > ~/.xmodmaprc

I opened ~/.xmodmaprc, skimmed through it to find the key occupations I was after: Y, X, S, L, Ä, period, menu key. As that’s not what you are interested in, here’s just what the respective entries look like in my modified ~/.xmodmaprc now:

• keycode 39 = s S bar section bar section
• keycode 46 = l L Home Left Home Left
• keycode 48 = adiaeresis Adiaeresis End asciicircum End asciicircum
• keycode 52 = y Y less guillemotleft less guillemotleft
• keycode 53 = x X greater guillemotright greater guillemotright
• keycode 60 = period colon Prior division Prior division
• keycode 117 = Next

If you, as I do, never log out of your current session (due to the convenience of hibernate mode), you can make the changes work immediately, without any need to restart the session first: On a console, for every of the above keycode lines, issue a

$ xmodmap -e "keycode line“

Notes: You don’t need to be root to gain the effect. And everything will be in effect just after you issued the modification command. To undo any modification, just restore the original look of the keycode line from the editor, then issue that by another xmodmap -e " ... ".

Gestern, recht unerwartet, hat mir ein Systemupgrade, den Sprung von Etch zu Lenny beschert. Logischerweise und, in diesem Fall nicht unerwartet, hat sich dieses Upgrade als recht zäh erwiesen. Ich habe Nachmittags angefangen und war dann gegen 23:00 Uhr soweit, eine neue Version am Laufen zu haben.
Das Problem hatte eigentlich viele Schichten. Zum einen habe ich Software installiert und wieder deinstalliert, ohne nachher aufzuräumen – Fehler Nummer eins. Dann habe ich es versäumt, die locale ordentlich zu konfigurieren, was zusätzliche Fehlermeldungen hervorgerufen hat. Außerdem – und das scheint auch wichtig zu sein – habe ich OpenOffice nicht deinstalliert. Apt hatte so seine Probleme mit der installierten Version von OpenOffice. Um die neue Version zu installieren, sollte die alte entfernt werden – zumindest, wenn man sich das Packet von CD installiert und das System ansonsten nicht ändert. Bei einem Versionssprung sollte während des Upgradevorgangs die alte Version enfernt werden und dann die neue installiert werden. Aus irgend einem Grund, hat apt aber die “apt-utils” nicht gefunden. Leider sind die Logfiles da auch keine Hilfe. Jedenfalls wurde das alte OpenOffice nicht entfernt und so kam es wie es kommen musste, es gab ein Packetkonflikt. Dazu kam bei mir der chronische Mangel an Speicherplatz. Mehrmals musste ich die Packete wieder löschen, nachdem die Installation mit der Meldung “No space left on device!” abgebrochen hatte. Gut nur, das das System kein Windows ist. Ein Neustart währe verhängnissvoll gewesen. So lief das System erstmal weiter. Also, mit “apt-get clean” die Dateien gelöscht um Platz zu schaffen und dann mit “apt-get install -f” die Installation fortgesetzt. Ist zwar nicht unbedingt eine elegante Lösung, aber durchaus praktikabel. Jetzt funktioniert wieder alles – wobei, im Gegensatz zum letzten Versionssprung, brauchte ich den X-Server nicht neu einrichten. Netzwerk läuft, meine Platte vom Server ist wieder per NFS gemountet, alle Routen passen, der Netzwerkdrucker ist erreichbar und läuft, der 2. Netzwerkdrucker am alten Laptop ist auch erreichbar und läuft (CUPS ist ok). Alle Anwendungen laufen – einige davon mit neuem Aussehen. Quasi alles in Butter.
Das es weitaus einfacher geht hat mir dann Petras Rechner bewiesen. Auf diesem läuft ebenfalls ein Debian Linux Etch – nun Lenny. Ein geschmeidiges “apt-get update && apt-get dist-upgrade -y“, hat das Teil sofort loswerkeln lassen. OpenOffice wurde entfernt und die neue Version installiert. Überhaupt wurden die alten Programme sauber entfernt und durch die neuen ersetzt. Anschließend noch ein “apt-get autoremove” und die alten, nichtmehr benötigten Programme waren auch weg. Heute dann nur noch den alten Kernel entfernen, dann hatte der Rechner ein richtig rundes System.