Ubuntu 10.04 "Android Ant-based build system requires Ant 1.8.0 or later"

I got this crap when I was trying to compile the sample android app:

gideon@desktop-i7:~/workspace/MyFirstApp$ ant debug
Buildfile: build.xml
-set-mode-check:
-set-debug-files:
-check-env:
BUILD FAILED
/home/gideon/android-sdk-linux/tools/ant/build.xml:377: The Android Ant-based build system requires Ant 1.8.0 or later. Current version is 1.7.1
Total time: 0 seconds

The fix is easy, just install the ant1.8 package:

apt-get install ant1.8 

That'll do.

What is the device name for mount

When you insert your SD card or USB drive to a system, there will be some kernel message, but you may or may not see the message depends on what UI or tty you're at. You know you need to mount it, if not auto mounted, but you don't know what is the device name, you can try the following:

Before you insert your SD card or USB drive

# cat /proc/partitions

This will show you the existing partitions. Now insert your SD Card or USB drive, wait until the kernel message is done, or wait 5-10 secs to make sure your kernel complete recognizing your drive.

# cat /proc/partitions

You should see something new like sdb or mmcblk0p1. Check your /dev to see the device node is already exist. If not, uses the device major and minor name showed in /proc/partitions, create it using mknod command:

# mknod /dev/<device name> b <major> <minor>

Then you can create your mount point e.g. mkdir /mnt/sdcard or /mnt/usb_driver and mount your partiton

# mount /dev/<device name> /mnt/<mount point>

Then you should be able to read your drive.  If /proc/partitions fails to show up, I would suspect something is wrong with your SD card or USB drive, or something to do with the driver.

Wordpress export to Blogger bX-8bpovo error

Wordpress sucks.  I like them open source but their ads and archives list modules just pissed me off.  And I can't do nothing about it when I just use their services.  I expected that the transition from wordpress to blogger wouldn't smooth, and that's right.  When you export your blog from wordpress and try to import the xml in blogger, you'll find the following error:

Finished: Sorry, the import failed due to a server error. The error code is bX-8bpovo

The xml is obviously not compatible.  Luckily there is someone (probably from Blogger?) put up a tool to fix the xml file:

http://wordpress2blogger.appspot.com/

After the conversion, the xml file imported successfully, and this blog is alive again.

C pointers and array examples

Some pointers and array examples

int ia[6] = {0, 1, 2, 3, 4, 5}; /* 1 */
int *ip; /* 2 */

ip = ia; /* equivalent to ip = &ia[0]; */ /* 3 */
ip[3] = 32; /* equivalent to ia[3] = 32; */ /* 4 */
ip++; /* ip now points to ia[1] */ /* 5 */
printf("%d ", *ip); /* prints 1 to the screen */ /* 6 */
ip[3] = 52; /* equivalent to ia[4] = 52 */ /* 7 */

argv
+---+
| 0 | ---> "./junk"
+---+
| 1 | ---> "-b"
+---+
| 2 | ---> "gradient"
+---+
| 3 | ---> "yeehaw"
+---+

**argv or *argv[] are equal. Array is just a pointer, and a double pointer is just an array of pointers.

Ubuntu make xconfig qt error

When you do make xconfig (graphical kernel config), you may receive following error

gideon@gideon-desktop:~/linux$ make xconfig
CHECK qt
* Unable to find the QT4 tool qmake. Trying to use QT3
*
* Unable to find any QT installation. Please make sure that
* the QT4 or QT3 development package is correctly installed and
* either qmake can be found or install pkg-config or set
* the QTDIR environment variable to the correct location.

In Ubuntu, you just need to install the qt4-dev-tools package to fix it.

# aptitude install qt4-dev-tools

Compiling Linux kernel (Cheatsheet)

I'm not sure if these instructions are distribution specific.   Currently I'm testing this with LinuxMint13 with Cinnamon.

To probe disks on the system for other operating systems:

# os-probe

Search the new kernel images and update the grub configuration

# update-grub

But in fact, kernel make install will automatically run update-grub..

# cd LINUX_SOURCE_TREE
# cp /boot/config-`uname -r` .config
# make menuconfig
# make -j4
# make modules
# make modules_install
# make install

Reboot! (Don't blame me if your machine doesn't boot!)

Installing new kernel (Debian/Ubuntu/Mint)

Should be quite easy?

 

Move kernel images and initrd to /boot

To probe disks on the system for other operating systems:

# os-probe

Search the new kernel images and update the grub configuration

# update-grub

Reboot!

Linux Mint 13 Black Splash Screen

In Linux Mint the boot splash screen is completely black. According their website it is by design not a bug. If you want to change the splash screen you can select one by typing the following command and selecting mint-logo:

sudo update-alternatives --config default.plymouth

postfix dovecot

I had been setting up my own server for website for like 10+ years but still this is my first time to get the e-mail working! Still excited!

I followed a website to use dovecot and postfix. Both are very easy to use! not like sendmail which is horribly complicated.

Basically you need the following packages: (Ubuntu 10.04)

aptitude install postfix dovecot dovecot-pop3d dovecot-imapd dovecot-postfix

For setup, the following is a good guideline:
http://wiki.centos.org/HowTos/postfix

Android apps sample code

If you are interested in develop Android applications, don't miss this sample source codes!

http://sudarmuthu.com/blog/10-open-source-android-apps-which-every-android-developer-must-look-into

Linux Chinese fonts

I love the 文泉驛 WenQuanYi font, it's already in the main debian/ubuntu repositories.

sudo apt-get install ttf-wqy-zenhei

Reference:
http://wiki.debian.org.hk/w/Where_can_I_find_fonts_for_GNU/Linux

http://cle.linux.org.tw/fonts/FireFly/