xuedi 的 blog
A BLUG Spammers BLOG

Archive for the ‘linux’ Category

temp scp alias

Saturday, September 4th, 2010

Quite often i am sitting with someone in some cafe working and ‘just’ want to copy a file over … even though we can today send bits and bytes all over the world, the communication of two people next to each other failing on stupid simple reasons quite often (no net-cat installed, samba not configured, nfs modules missing, someone remember the hassle of serial dialog cables ^^) well, the point i try to make here is that for me the most simple and fast is still ssh.

But, with the situation to freelance in changing cafe places and just shortly here and there send some files to different people my .ssh/known_host file grow to about 120 entrys. I can not recall (trust) any of them, so the point of the warning at a man-in-the-middle attack is useless …

I was searching for quite some time (read here and there a few lines of the manual) for a simple –no-host-check option for ssh. Now i found it:


alias mscp='scp -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null'

It is very convenient to have a guest user (no bash / login, with password) account on the system, so you just do sshd->start … then: mscp (mobile-scp) and there is your file … sshd->stop

Cheers
xuedi

annoying bug on the N900

Thursday, August 26th, 2010

Really annoying and not fixed since 3 months:

last 1.2 release, signed in on Skype via 3G change to wiki and Skype is f**ked up, can sign in any more, only solution is to remove the Skype account and create it again. For me this mean to merge 100 contact into my phones address book again.

Nokia and Skype do not even reply to the Ticket i wrote via Support. its in the maemo bug Tracker since month with the info: it depends on action from Skype or Nokia….

Great, reason no. 1 to buy the N900 is not working any more :-( So far i had only great experiences with the phone, hope it will be fixed soon…

great progress on my game project

Monday, June 21st, 2010

Hello there,

recently i started massively working on my game project again, and i really fall in love with doxygen and mercurial :-)

Check it out

The only problem is i am running out of money because i program to much for hobby ^^

Cheers
xuedi

New Ubuntu and binary

Tuesday, April 27th, 2010

Good news,

The 10.10 release of Ubuntu will increase all kind of stats, network speed, hard disk size and so on. And no one need to do any kernel magic for that ;-)

What i am talking about is that 10.10 will have finally implemented the binary norm from 1998 and now there is a difference between 1000MB and 1024MB so only fields where it is really necessary like counting the memory it will be kept in binary counting. All human readable values like hard disk, network bandwidth and so on will be counted in 10 system. To make that clear 1MB will be in the future 1000kB, and in binary counting 1MiB will be 1024KiB so the ‘i’ is the new part the signalize binary counting. That should make calculating much more easy and help the USB-Stick sellers to finally have the right size for free :-P (previous 1G stick was 931MB) now a 1G stick will have exact 1000MB ^^

Cheers
xuedi

Remote control rhythmbox

Thursday, April 8th, 2010

Programmer are good ones if the are lazy in their style of work, and i using that concept for all my live. So one of my new laziness gadgets, imagine you lie in bed, but your laptop is playing music on your working desk, now a song came up you want to skip or you want to change the volume. Given the fact you have a ssh comparable device like i have my N900 with you, you can easily remote control rhythmbox.

The command line control is rhythmbox-client, unluckly its an GUI app that gets a bit confused if the right environment variables are not set, so that how i make it run easily for me.

First:

Make sure you can access the machine that runs rhythmbox easily, my laptop runs a SSH server, so first i created a certificate on my N900, this is not nessesary if you have there alreada a xxx.pub file:

cd /home/<yourUser>/.ssh
ssh-keygen -t rsa

Second:

You need to make your machine that runs the music play to know that this created certificate is accepted, therefor you need to register it, the first variable here is the key file its called something xxx.pub depending if you use rsa or another algorithm. You also need to copy that key over via SSH so you need to enter the name and ip or your machine that runs rhythbox:

ssh-copy-id -i /home/<yourUser>/ssh/id_rsa.pub <user>@<hostname_or_ip_address>

Third:

Make it more easy to access your remote music machine, if you use it only in a home wifi you can create a SSH config file and if you gave your machine that runs ryhthmbox a name lets say ‘myLaptop’ then this command will connect you via SSH: ‘ssh myLaptop’ but you can choose freely run ‘vim /home/<yourUser>/.ssh/config’ and enter this config option:

Host myLaptop
User yourUser       #or whatever you like
Port 22
Hostname <MusicPlayersIP>
IdentityFile /home/<yourUser>/.ssh/id_rsa
TCPKeepAlive yes
IdentitiesOnly yes

Forth:

The command to change your rythmbox need some variables set as well, that makes it quite long, so i suggest you create an alias for that, normally you do that in ~/.bashrc (for your user only) /etc/bash.bashec (for systemwide) but if your machine like mine N900 just using shell not bash you need to use ~/.profile . Add  now the alias command to our file of choice:

alias rc='ssh yourUser@myLaptop env DISPLAY=:0.0 rhythmbox-client --no-start'

Usage:

You can use that new command now for:

  • rc –help                    # get all options
  • rc –next                    # next song
  • rc –previous            # next song
  • rc –volume-up        # louder
  • rc –volume-down  # more quite
  • rc –pause                 # pause the music
  • rc –play                    # start playing music

Some tip, the volume up and down command just change the internal rhythmbox level, so before you go with some beers, sandwiches, to bed an plan to stay there all sunday long, set the rhythmbox level to middle and ajust your system sound level to normal room sound, now you have room for more lous and more quite, and no reason to get up at all … well, get some empty plastic bottle and you even can save the way to your washroom ;-)

N900, N810, N800 Users

You can also create a desktop icon for ever singe command and create your own remote control looking desktop, but don’t be inpatient, command via SSH take a second to work, so don’t press 10 time more loud, that will be still executed just a second later and you neighbors might not like it…

Cheers
xuedi

N900: partitioning

Thursday, March 11th, 2010

There are some good guides in the wiki, but they use sfdisk and you have to calculate the blocks yourself, what a pain, here is the way how to install fdisk on tn N900

cd /root
wget http://ftp.de.debian.org/debian/pool/main/u/util-linux/util-linux_2.13.1.1-1_armel.deb
dpkg-deb -x util-linux_2.13.1.1-1_armel.deb root
cp root/sbin/fdisk .
rm -r root/
rm util-linux_2.13.1.1-1_armel.deb

In general it from huge advantage if you have a MicroSD card, then you can copy your MyDocs and the /home stuff first and can delete both partitions, after reboot you are totally free to repartinion as you like, after that mount the new partitions, copy the backup back where they belong and reboot again. It worked well if you change the design, for ex. have the vfat on the secon part, but some 3rd party< programms might not like it, so better keep it: part.1=cfat (MyDocs), part.2=linux (Home), part.3=swap. my actual partition table looks like this:

1. 3G vfat
2. 27G ext3
3. rest swap

N900, too much fun

Thursday, March 11th, 2010

Finally i got my N900 and the first think i tried to do is to swap the 27G (vfat) with the 2G (ext3) partitions, went good so far, but then i messed up and reboot by accident (wrong terminal, wanted to shutdown another machine) and my N900 starts crashing on the initial start (inf. loop), now i need not even flash the normal firmware, but do a full overwrite and reset the whole internal memory card, how embarrassing …

I think this time i got for no vfat and sawp at all, just create a single ext3 over the 32G (minus the 256) and do the sawp as well as the vfat (needed for the camera) in the file system via loop device. So then i will be able to resize them dynamicly in care i need more space for photos or bigger swap if i like to run apache ^^

Filesystem: 32G ext3
- 1,5G /swap
- 1,5G /vfat

I am btw extremely surprised by the speed of the 900 compare to the 800 series, the only sad point is a little offset in the map software.

xuedi

working again on my game

Tuesday, March 9th, 2010

History

long time i did not do anything on my game, i had the idea already in 1999. I had always time where i developed a lot, then ot boring and stoped, after a while i found a new better fitting library and i rewrote the whole shit, that happen about 11 time … so almost a rewrite a year, now i had a chat with a fellow BLUG’er and got some new inspiration. This time i will do it the real way, write a road-map first, and do the easy stuff first and then continue, so i wont stuck in reinventing a HTML kind of parsing and browsing system and give up at the end.

Idea

The idea itself did not change for a long time, its a MMORPG where the character is a spaceship witch is highly customizable it will be cross platform and the inicial server will deal with 1024 clients. It will be a one universe game, no instances, some basic components are:

  • allegro 4.9 (alias 5 based)
  • 2D game more comic than realistic look
  • using raknet network library (interesting fair license)
  • own window system
  • realtime action
  • influence by eve online
  • free and open-source not sure what license yet
  • C++ based (server & client)
  • 3D client possible later
  • open network protocol for 3rd party clients

Roadmap

This is just an pre road map, more an idea collection first step first i will do the basic server client communication with some chat system, then the serves object handling and then the clients object display, following that the objects attributes as well and the client interaction with objects over the server, then its already 2020 and i will think about the rest ;-)