By default, You need to guide Vim to decode double-byte encodings like GBK and Big5. The default Vim configuration only works well with Unicode encodings including utf-8, utf-16, utf-16be etc..Edit your .vimrc file, add line like:

Now Vim is able to detect and decode GBK and Big5 encodings automatically. And according my experience, Vim respects utf-16 and utf-16be files only they have BOM byes. Otherwise, these files are wrongly decoded. In this case, you may want to manually reopen the file using a correct encoding. The Vim command like:

And Vim does not store BOM when saving by default. To enable/disable BOM saving, use:

I’ve attached a series of text files to learn the usage. These text file all contains string “123你好”, but saved in different encodings. Let’s list their code points first:

1 2 3
GBK 0x31 0x32 0x33 0xc4e3 0xbac3
Big5 0x31 0x32 0x33 0xa741 0xa66e
Unicode 0x31 0x32 0x33 0x4f60 0x597d
UTF-8 encoded 0x31 0x32 0x33 0xe4bda0 0xe5a5bd

And our hexdump’s here, note the byte order:

My test text files are here. More info:

The objective of this article is to make Vim your programmer’s editor.

First, a normal version of Vim should be installed to enable syntax highlighting. The default installation of Ubuntu 10.04 only contains a compact version “vim-tiny”:

Then copy a local vim configure file:

1. Line Number

Add line into the .vimrc file:

A similar command can be used to show/hide line number when editing on the fly:

Related help:

2. Tab-space Conversion

From the Vim help:

'tabstop' 'ts'          number  (default 8)
                        local to buffer
        Number of spaces that a  in the file counts for.  Also see
        |:retab| command, and 'softtabstop' option.

        Note: Setting 'tabstop' to any other value than 8 can make your file
        appear wrong in many places (e.g., when printing it).

        There are four main ways to use tabs in Vim:
        1. Always keep 'tabstop' at 8, set 'softtabstop' and 'shiftwidth' to 4
           (or 3 or whatever you prefer) and use 'noexpandtab'.  Then Vim
           will use a mix of tabs and spaces, but typing  and  will
           behave like a tab appears every 4 (or 3) characters.
        2. Set 'tabstop' and 'shiftwidth' to whatever you prefer and use
           'expandtab'.  This way you will always insert spaces.  The
           formatting will never be messed up when 'tabstop' is changed.
        3. Set 'tabstop' and 'shiftwidth' to whatever you prefer and use a
           |modeline| to set these values when editing the file again.  Only
           works when using Vim to edit the file.
        4. Always set 'tabstop' and 'shiftwidth' to the same value, and
           'noexpandtab'.  This should then work (for initial indents only)
           for any tabstop setting that people use.  It might be nice to have
           tabs after the first non-blank inserted as spaces if you do this
           though.  Otherwise aligned comments will be wrong when 'tabstop' is
           changed.

I will choose to use the 2nd approach, so add:

The auto-indent feature is also useful:

When setting expandtab, a real tab can be input by <Ctrl-v>_<Tab>

Related help:

3. Option ‘modeline’:

If you start editing a new file, and the ‘modeline’ option is on, a number of lines at the beginning and end of the file are checked for modelines. This is simply enabled by adding:

Your C/C++ comment may look like one of the following:

And likely, the Python comments:

Here, ai, et, ts and sw are just abbreviations. And expandtab is an option only in Vim, not Vi.

Read related help by typing:

4. Using Taglist:

There are lots of useful scripts in the Vim website that we can use. But Actually, Ubuntu repository also has some of them included:

After installation, these scripts are just downloaded, but not installed for your Vim. We list available script by typing:

Output on Lucid 10.04:

The Taglist plugin is described here, while OmniCppComplete plugin in next section. Both of them make use of ctags utility. Install it first:

Now install the Taglist plugin to your Vim:

When editing a supported file type, Show the taglist window can be opened by one of the following:

Move your cursor between windows by <Ctrl-w>_w as usual. You may want to add a shortcut to toggle this feature. Add lines to your .vimrc file per official document:

When your cursor hovers on a function, <Ctrl-]> takes you to its declaration, while <Ctrl-t> takes you back.

More help:

5. Using OmniCppComplete:

Vim include basic support for code completion. The simplest way is to use <Ctrl-p>. Vim will search your include headers and do insertion. See the screenshot:

vim_ctrlp

The include search path can be set by:

More help info:

Next, Vim provides basic C language completion using ctags. No C++ is supported. Additional languages script can be found in Vim’s autoload directory, say /usr/share/vim/vim72/autoload. But you should generate necessary ctags index files first. For libc6 header files:

And add lines to .vimrc file:

Omni completion can be issued by <Ctrl-x>_<Ctrl-o>.

Screenshot showing function prototype:

vim_omni_c1

Screenshot showing struct member completion:

vim_omni_c2

More help info:

Note, the ccomplete does not work well in C++ completion. So we need to install OmniCppComplete plugin:

Generate ctags index for libstdc++ and qt4:

And add lines to .vimrc file:

You may encounter problems when completing STL functions. Refer to :help omnicpp-faq and find the solution. Anyway, it works all good for me. Here’re screenshots showing STL and Qt code completion:

vim_omni_cpp1

vim_omni_cpp2

!!!NOTE!!! : The tags file for current file must be generated for OmniCppComplete to work. I’ve set Ctrl+F12 as the accelerate key. Otherwise, you’ll get “Pattern not found” error. More help:

Finally, the list of lines adding to my .vimrc file:

Got a new EeePC 1015PX this week. I just installed the netbook version of Ubuntu 10.04.2 and all devices are recognized. Only some small tweaks are needed:

1. Add the partner repository

Go to System –> Administration –> Software Sources –> Other Softwares tab, check the partner repository. Then software like Sun’s JDK and Skype become available. Skype works fine with my webcam.

2. Tweak asus hotkeys

The volume and wireless hotkeys do not function by default. Here’s the official solution in wiki.

Find GRUB_CMDLINE_LINUX_DEFAULT parameter and modify it as follow:

Then update grub installation with the command and reboot:

Update Feb 17, 2012: acpi_backlight=vendor dims initial screen brightness, and make it difficult to adjust it later. Now I use acpi_backlight=video to avoid this.

3. Disable touchpad

It’s necessary to disable the touchpad while typing. It annoying because it’s always mis-clicked and cause input focus to move away. Many threads in forums discussed about this, but none works for me. The .32 kernel just recognizes the touchpad as a mouse, thus cannot be disabled. Then I just install the .35 kernel in the backport repository:

After reboot into the new kernel, run:

The touchpad finally recognized correctly. Then continue installation:

Go to Preference –> Touchpad, uncheck “Enable touchpad”.
Go to Preference –> Mouse –> Touchpad tab, uncheck “Disable touchpad while typing”. If this option is not disabled, your touchpad will be enabled after you type something.

Update Jul 15, 2011: Newer .32 kernels from 2.6.32-33 recognize the touchpad correctly. So if you use later versions or fresh install your ubuntu from 10.04.3, there’s no need to install .35 kernel.

4. Autohide top panel

I installed the netbook UI by:

There’s no autohide property in the context menu of top panel of the UI. I had to modify it manually:

5. Hide menu/bookmark bar in firefox

Too small content area in firefox by default. To hide bookmark bar, just find and uncheck the option in View menu. To hide menu bar, you need to install an extension called “Compact Menu 2”. It compacts the whole menu as a single button in navigation bar. In addition, you may also want to disable the “webfav” extension to make room.

6. Adjust screen panning

Some application is not netbook-friendly. Their windows are just to large, even beyond 1024×600. To view the whole window, you can set the logic resolution of your screen. And it scrolls when your mouse pointer reaches the border of the physical screen. First, find the output of your screen by:

The current output name may be VGA*, LVDS* or else. Then change your logic resolution of it like:

7. Tweak startup applications

Go to System –> Preferences –> Startup Applications, uncheck unnecessary items. For me, they are:

  • Evolution Mail Notifier (unused)
  • Print Queue Applet (unused)
  • Visual Assistance (unused)
  • Bluetooth Manager (no bluetooth device)
  • Maximus Window Management (no need to the feature)

8. Make Vim your text reader

I read novels in text files, I want to keep track of the last reading position automatically.

Search and uncomment the line as guided:

9. Switch between gcc versions

Sometimes, a specific version of gcc/g++ is needed to build a project. I simplify this by making use of the “update-alternative” utility. Suppose you have installed gcc-4.1 and gcc-4.4:

Then you can switch versions by:

Actually, other less used symbolic links also need configure like this. They are gcov, i486-linux-gnu-gcc, i486-linux-gnu-cpp.

In previous articles, I was not able to use Qt’s debug package provided by Ubuntu. Now, I will explain how to use them.

Our simple application:

Our *.pro file, you should enable the debug build:

1. Build your debug version of application:

2. Install Qt’s debug package:

3. Install the Qt source:

Now you can start debugging your application. Since Qt’s debug symbols are installed in /usr/lib, It does not follow the GDB’s global debug directory described here. We should tell GDB to load these symbols manually:

We set a breakpoint at the beginning of main function to load all shared libraries. Next, we will load symbols for libQtCore.so.4. The symbol will be loaded in the start address of it (0xb7652510):

Now, you are able to step into the Qt library, but no source is attached:

Source files are attached by:

See the source and backtrace? 🙂

Finally, we comes with the C# language. C# supports all OO features mentioned in previous articles in language level. So, our implementation is quite straight forward. Just check the source code in my skydrive: http://cid-481cbe104492a3af.office.live.com/browse.aspx/share/dev/TestOO. In the TestCSObject-{date}.zip file.

Lastly, I drew a simple table to compare and summarize the OO supports in the four leading languages:

C/gtk+ C++/Qt Java C#
Basic Features
Encapsulation library good design Y Y
Inheritance library Y Y Y
Polymorphism function pointer Y Y Y
Advanced Features
Property library library reflection feature Y
Meta Info library library annotations attributes
Event Driven library(signals) library(signals/slots) events/listeners delegates/events/handlers
Measurements (Using a test application to demostrate above 5 features)
Compiler mingw32-gcc/3.4 mingw32-g++/3.4 JDK/1.6.20 VC#/2005
Library gtk+/2.16.6 Qt/4.3.5 Java/6.0 .NET/2.0
Source Size 19.09 KB 7.28 KB (+10.17 KB) * 13.18 KB 6.28 KB
Binary Size 32.69 KB 34.00 KB 9.48 KB 5.50 KB
Runtime Size 1.46 MB 2.00 MB 15.54 MB 23.84 MB
* Generated source