command to display motherboard's model

command to display hardware:

$ sudo lshw | less

command to display motherboard's model:

$ sudo dmidecode | less

QQ at Ubuntu crash

QQ is a very popular instant messenger software in China. Links to download QQ for Linux:
http://im.qq.com/qq/linux/download.shtml

However, when it runs, it always crash.
(Currently I'm using Ubuntu 8.04LTS)

Edit the following file can solve the problem:
vi /usr/bin/qq
#!/bin/sh

add the following line:
export GDK_NATIVE_WINDOWS=true

USB OTG

USB is a good interface but it can be very complicated and confusing(probably only for developers?)

The USB mini-male has 2 types:

• Mini-A-male


• Mini-B-male

The USB OTG devices detect itself as a host or client depends on the ID pin(pin 4). USB Mini-A-male has internal wiring to tie the ID pin to GND, which let the host to identify itself as USB host.

While most of the USB Mini-male cable you see on the market is Mini-B-male, which leave the pin unconnected.

gitweb on Ubuntu/Jaunty

Make sure these GIT packages are installed:

$ aptitude install git git-core gitk gitweb

Assume the default apache web server is /var/www/ ,
gitweb is the directory I want to install gitweb:

$ cd /var/www/
$ mkdir gitweb
$ cd gitweb

copy gitweb graphics and stylesheets(git-favicon.png git-logo.png gitweb.css) to its directory, their path should correspond to what states in /etc/gitweb.conf:

$ cd /var/www/gitweb/
$ cp /usr/share/gitweb/* .

add gitweb directory to apache2 configuration by creating a "gitweb" file inside apache conf.d directory:

$ vi /etc/apache/conf.d/gitweb

Paste the following text and modify if your path is different:

Alias /gitweb /var/www/gitweb

Options Indexes FollowSymlinks ExecCGI
DirectoryIndex /cgi-bin/gitweb.cgi
AllowOverride None

Modify gitweb.conf, assuming the public GIT repositories are located in /var/www/repo/

$ vi /etc/gitweb.conf

$projectroot = "/var/www/repo/";

# directory to use for temp files
$git_temp = "/tmp";

# target of the home link on top of all pages
#$home_link = $my_uri || "/";

# html text to include at home page
$home_text = "indextext.html";

# file with project list; by default, simply scan the projectroot dir.
$projects_list = $projectroot;

# stylesheet to use
# I took off the prefix / of the following path to put these files inside gitweb directory directly
$stylesheet = "gitweb.css";

# logo to use
$logo = "git-logo.png";

# the 'favicon'
$favicon = "git-favicon.png";

restart apache2 web server:

$ sudo /etc/init.d/apache2 restart

Now you should be able to view gitweb listing all GIT projects under /var/www/repo/:
http://localhost/gitweb

vi copy and paste format problem

when copy and paste in vi it automatically inserts many annoying indents and tabs. To disable the auto indents and formatting, use this command before you paste

:set paste

and paste your codes. After that, set it back

:set nopaste

8051 Linux programmer

I just had no luck searching for this topic. Any one come across the same idea please shed me some lights.

Any cheap (universal) programmer out there can be used to compile 8051 C programs and also capable of writing the hex file into 8051 derivatives? I would also like to know what packages/compilers/similators to drive this programmer.

vim autocomplete

For some reason Ubuntu 8.04 didn't install vim by default, thus no syntax.

There's also another tips I always forgot.  vim has a very nice autocomplete feature.  For example you've a variable name "apple", you can type "ap", then press Ctrl-n or ctrl-p, it would show all the functions and variables start with "ap".

How to change the default system shell back to bash

For some reason, Ubuntu changed the default system shell from bash to dash.  To what I noticed, I didn't see any speed improvement but many scripts shows error or are not compatible.

To restore the whole system back to bash, call this command:

sudo dpkg-reconfigure dash

Typing Chinese in English Ubuntu 8.04

Update on Sept 12, 2010
For tips to install Chinese in any Debian based system, please follow this links:

• Chinese Debian Mini Howto


• Make Debian support Chinese

---

I always prefer to install the OS in English and enable Chinese.  However, Chinese tool (scim) is not installed by default. Followings are my steps to enable Chinese support and typing in Ubuntu(6.04 ?)

1. Go to System -> Administration -> Language Support
   Choose Chinese (Traditional and/or Simplified)


2. install packages scim-chinese, scim-tables-zh, and all other dependencies


3. $ vi /etc/X11/xinit/xinput.d/scim
   change xim input to scim 
   
   GTK_IM_MODULE="scim"
   QT_IM_MODULE="scim"


4. without using root, type
   $ im-switch -z <Your locale> -s scim
   your locale can be figured out by command
   $ locale | grep LANG


5. restart your X (Ctrl-Alt Del), then Ctrl-spacebar should give you a scim toolbar

P.S. After the scim toolbar is poping up, you still need to right click the toolbar to setup what input method you would like to use.  Personally, I used Changjie3 to type Chinese, it seems the closest to the Windows version of Changjie.

P.S.  I wonder if there is easier way...

yum database clean up

Sometimes when yum is not updating, or simply not synchronized with the repository, it's a good idea to clean up the cache database and fetch a new list from the server.

1. yum clean all


2. mv /var/cache/yum/ /tmp/


3. mv /var/lib/rpm/__db* /tmp/


4. rpm --rebuilddb

Somehow I tend to move the files to /tmp/ rather then just remove them, since the rm -rf command is the No. 1 enemy of idiocity.