Thoughts in Air

The Headache of a Separate /usr Partition

2012-01-31T21:33:00.002+08:00

I installed Arch Linux inside a VirtualBox. Originally I made a bad decision and only allocated 20 GB for the whole Linux hard disk, among which root partition occupies 8.3 GB. Later on, I found that I need to squeeze disk spaces since the root partition is quickly occupied by ever increasing packages. Then I decided that I need to add another disk to balance the load of root partition. Which directory shall I put on the separate partition? After looking at the disk usage, /usr seems a nice candidate. So I created another virtual disk, moved all /usr content to that disk, and mount it as /usr. There were problems in this process since /usr contains many important binaries, but I overcome these issues. Finally I have enough space in my root partition, although everytime Arch Linux boot process complains that separate /usr partition is not supported. I didn't care since everything went fine.

Yesterday I rebooted Linux. During boot process, Linux complained that /dev/sdb1 is mounted. e2fsck: Cannot continue, aboring. I was given a typical panic screen to either enter root password and fix the problem, or hit Control-D to continue. /dev/sdb1 is where my current /usr partition. So I knew that I was finally hit by the separate /usr partition problem.

How to solve the problem? After Googling around, the solution is to disable boot time disk checking, as discussed here. So I entered root password, and mounted root partition as writable by typing mount -o remount,rw /. Then I edit /etc/fstab. The trick here is to change the last parameter (pass) to 0 for partition /dev/sdb1. The line

UUID=adbe588d-fd82-4ab1-b935-5ea245cf89fa /usr ext4 defaults,noatime,nodiratime 0 2

is changed to

UUID=adbe588d-fd82-4ab1-b935-5ea245cf89fa /usr ext4 defaults,noatime,nodiratime 0 0

There are issues with such solution though. Boot time disk checking is useful to ensure data consistency. The solution bypasses such safety guard. But currently I cannot find any other solutions to boot the Linux box. Since I cannot check the partition after booting (since /usr is busy), I may need other ways to check the partition (maybe boot via CD-ROM and check the partition manually). The lesson here is that a small decision error at the beginning may have large implications at the end.

Displaying ANSI Escape Sequences in Windows

2011-11-07T21:08:00.000+08:00

I installed Busybox on my Samsung Galaxy S II to enjoy the Swiss Army Knife of Embedded Linux. When I want to look at my phone SD card content, I often use adb if the phone is connected with my laptop. So I typed the following command at Windows command prompt:

adb shell ls /sdcard

What I got is somehow scary as shown below (only first line is shown):

←[1;34mAndroid←[0m ←[1;34mTitaniumBackup←[0m

After a while, I realized that what is shown is actually ANSI escape codes. The ls command provided by Busybox is actually showing color codes by default.

So what shall I do? I know option --color=never can suppress ANSI escape sequences but I don't like typing such long keystrokes. On the other hand, getting useful information out of those ANSI codes is very difficult. My first reaction is trying to see whether Windows shell can show those ANSI codes. I remember my old friend DOS can display ANSI codes, so a modern Windows 7 should be able to do so. But I cannot find relevant configuration in Properties dialog of command prompt. After reading Wikipedia page on ANSI escape codes, I found the following sentence Console windows in all versions of Windows do not support ANSI escape sequences at all. Therefore the only solution is to find some console replacements which can show ANSI codes.

I do found some by Googling. But before trying one, I asked myself why I should install one software for just such a trivial task? I suddenly thought: how about Emacs shell? Maybe Emacs folks have already solved this issue? So I fired up Emacs, typed M-x shell, and typed adb shell ls /sdcard in Emacs shell. Bingo! All ANSI color codes are correctly shown, just as in an Linux box when typing ls --color.

Ubiquitous Emacs to the rescue again.

Mobilizing All Forces

2011-09-10T10:10:00.000+08:00

Recently I played a corresponding game at chess.com. It is one of the games I played in 16th Chess.com Tournament. It is an interesting demo on how Black can attack the King sides in King's Indian Defense. Below is the PGN and an embedded PDF analyzing the game.

[Event "16th Chess.com Tournament (1801-2000) - Round 1"]
[Site "Chess.com"]
[Date "2011.09.01"]
[White "ismail231"]
[Black "whily"]
[Result "0-1"]
[WhiteElo "1810"]
[BlackElo "1873"]
[TimeControl "1 in 3 days"]
[Termination "whily won by resignation"]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 O-O 5.e4 d6 6.Be2 e5 7.O-O Nc6 8.d5
Ne7 9.b4 Nh5 10.Re1 f5 11.Ng5 Nf6 12.f3 Kh8 13.Be3 Bh6 14.Nf7+ Rxf7
15.Bxh6 f4 16.Rf1 Neg8 17.Bg5 h6 18.Bh4 g5 19.Bf2 Rg7 20.c5 g4 21.fxg4
Nxg4 22.Kh1 Qg5 23.Bf3 N8f6 24.Qe2 Nxf2+ 25.Rxf2 Bg4 26.Nb5 Bxf3
27.gxf3 Rag8 28.h3 Nh5 29.Qc2 Qg3 0-1

alt : 2011-09-01-ismail231-vs-whily-kid.pdf

The Power of Two Bishops

2011-08-26T15:55:00.000+08:00

Recently I played a corresponding game at chess.com. It is one of the games I played in a Semi Slav thematic tournament. At the end of the game, my two bishops completely dominates the board. Below is the PGN and an embedded PDF analyzing the game.

[Event "12th Chess.com Thematic Tournament - Semi Slav (1801-2000) - Round 1"]
[Site "Chess.com"]
[Date "2011.08.01"]
[White "BennyNevis"]
[Black "whily"]
[Result "0-1"]
[WhiteElo "1768"]
[BlackElo "1876"]
[TimeControl "1 in 3 days"]
[Termination "whily won by resignation"]

1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 {Thematic Game - This is the starting position.} 
 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 Bb7 9.a3 Bd6 10.O-O O-O
 11.b4 a5 12.Rb1 axb4 13.axb4 Qe7 14.Qb3 Nd5 15.Nxd5 exd5 16.Bd2 Nf6 17.Ra1 Ne4 18.Bc3 Nxc3 
 19.Qxc3 Bxb4 20.Qc2 g6 21.g3 Bd6 22.Kg2 f6 23.Nd2 c5 24.dxc5 Bxc5 25.Bxb5 d4+ 26.Kg1 dxe3 
 27.fxe3 Qxe3+ 0-1

alt : 2011-08-01-bennynevis-vs-whily-semi-slav.pdf

Transition from Attack to Defense

2011-08-19T19:19:00.001+08:00

Recently I played a corresponding game at chess.com. It is one of the games I played in a Ruy Lopez thematic tournament. I attacked first, but later on have to defense and lost the game quickly (as I thought). Below is the PGN and an embedded PDF analyzing the game.

[Event "Ruy Lopez - Round 1"]
[Site "Chess.com"]
[Date "2011.07.25"]
[White "nadreck"]
[Black "whily"]
[Result "1-0"]
[WhiteElo "2022"]
[BlackElo "1882"]
[TimeControl "1 in 5 days"]
[Termination "nadreck won by resignation"]

1.e4 e5 2.Nf3 Nc6 3.Bb5 {Thematic Game - This is the starting
position.}  Nf6 4.O-O Nxe4 5.Re1 Nd6 6.Bxc6 dxc6 7.Nxe5 Be7 8.d4 Be6
9.Bf4 O-O 10.c3 Nf5 11.Nd2 c5 12.g4 Nh4 13.dxc5 Bxc5 14.Ne4 Bd6
15.Nxd6 cxd6 16.Nd3 Qd7 17.f3 Qc6 18.Re3 Bxg4 19.Nb4 Nxf3+ 20.Kh1 Qd7
21.Rxf3 Bxf3+ 22.Qxf3 Rfe8 23.Rg1 Re6 24.Nd5 Rae8 25.Qg4 1-0

alt : 2011-07-25-nadreck-vs-whily-ruy-lopez.pdf

Wild King's Gambit

2011-08-02T22:16:00.002+08:00

Recently I played a corresponding game at chess.com. I played King's gambit, and the game went wild as what usually happens in this opening. Both white and black kept making tactical blunders and I won the game although I just intended to draw the game at the critical moment. Below is the PGN and an embedded PDF analyzing the game.

[Event "The super wally's that will crush YOU!!! - Board 36"]
[Site "Chess.com"]
[Date "2011.07.22"]
[White "whily"]
[Black "graywyvern"]
[Result "1-0"]
[WhiteElo "1896"]
[BlackElo "1822"]
[TimeControl "1 in 5 days"]
[Termination "whily won by resignation"]

1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bd6 8.d4
 f3 9.O-O fxg2 10.Kxg2 h6 11.Nc3 Nbd7 12.Bf4 Nb6 13.Qe2 Qe7 14.Rae1
 Kf8 15.Nb5 Qd8 16.Nxd6 cxd6 17.Ng6+ fxg6 18.Bxd6+ Kg8 19.Rxf6 1-0

alt : 2011-07-22-whily-vs-graywyvern-kga.pdf

One technical note: I generated the PDF file by using LaTeX package xskak, which is great for chess articles/books.

Switching From Gentoo Linux to Arch Linux

2010-12-25T22:40:00.006+08:00

Introduction

Although I have been using Gentoo Linux for several years, I started to consider switching to other Linux distributions. The main drawback of Gentoo is that too much time is spent on compiling. It is really cool to build a cutting-edge system, however the time spent on building it and maintaining it is enormous. Therefore I am searching a minimalist's Linux distribution with binary packages. Arch Linux seems to be quite good. I gave it a try under VirtualBox 4.0. The reference I used was Beginner's Guide.

Install the base system

The overall installation steps are quite similar to Gentoo: you need to configure many things by hand. The difference is that the installation is significantly faster.

If possible, one should select the fastest mirror since downloading time is the most significant component of installing Arch Linux packages. For me, I select the mirror listed here with the best score for my location. After determining the mirror, you can download the ISO image from that mirror, and add it to your /etc/pacman.conf after installation. For example by adding Server = http://mirror.url/archlinux/$repo/os/x86_64 under the repo names, or uncomment preferred mirros in /etc/pacman.d/mirrorlist (which is preferred). As an alternative, one may also try reflector after installing Arch Linux. Yet another option (I'm currently using) is to rely on script rankmirrors (according to here) to select the fastest mirrors. Note that for rankmirrors option, file /etc/pacman.conf needs one line Architecture = x86_64.

To enable the compatibility with 32-bit legacy programs (like Android emulator), multilib should be enabled in pacman.conf as below:

[multilib]
Include = /etc/pacman.d/mirrorlist

Simply download the latest ISO image. I used "core" image since it contains all the base packages for installation. The latest version as writing is archlinux-2011.08.19-core-x86_64.iso. Download and mount it under VirtualBox. Then boot the virtual machine.

For help, open a virtual terminal (by typing Alt+F2) and type less /arch/beginnersguide.txt

The installation steps are as follows:

Login as root.
Type /arch/setup to start the installer.
Select the source as "core-local".
Select Editor according to your taste.
Set the clock by selecting region and timezone according to your location. You should know whether your hardware clock is UTC or local (my settings in VirtualBox is UTC). The recommended setting is UTC.
For "Prepare Hard Drive(s)", firslty I choose "Manually Partition Hard Drives" and then "Manually Configure block devices, file systems and mount points.". I only setup two partitions, /boot partition (200 MB, ext2), and root partition (remaining disk, ext4.)". For menu "Partition Access Method", select "uuid".
After completing partitioning, go back to main menu and select "Select Packages. For bootloaders, choose "grub". Then for package, select "base-devel" meta-package as well, and select following packages in addition: gpm, inetutils, linux-header, mlocate, ncurses, openssh, pacman-mirrorlist, readline, sqlite3, sqlite3-doc, sudo, xinetd.
Select "Install Packages" from main menu. Select "Yes" to keep packages in pacman cache.
Select "Configure the System" from main menu.
- Modify /etc/rc.conf. Change "foo" to your desired host name.
```
# NETWORKING

interface=eth0
```
  I also removed netfs from DAEMONS line.
- Write your desired host name to /etc/hostname.
- Modify /etc/fstab by adding options noatime and nodiratime to partition /.
- Modify /etc/locale.gen by uncommenting the lines starting as "zh_CN" since I'm a Chinese.
- Modify /etc/pacman.conf by uncommenting the Xfercommand line in /etc/pacman.conf for wget.
- Modify /etc/pacman.d/mirrorlist by uncomment your preferred mirrors as discussed above.
- Change root password.
Back to main menu, select "Install Boot loader". Add option "vga=0x360" for customed VESA mode provided by VirtualBox (as discussed below). Install the bootloader to master boot record (sda in my case).
Finally, select "Exit Install" and type reboot to turn on the new system.

Configuration and Graphics User Interface

This section documents further installation and customization I made.

VirtualBox related settings

Install custom VESA mode to support your PC/Laptop's screen resolution according to VirtualBox manual, if necessary.

Install VirtualBox guest additions as shown below (note that we need to install kernel headers first to compile the additions). Reboot is needed to make additions work. Note that if you want to install Xorg, you can run VBoxLinuxAdditions.run after completing pacman -S xorg. Optionally package xorg-xinit can be installed for script startx and package rxvt-unicode for a nice terminal.

# mkdir /mnt/cdrom
# mount -t iso9660 /dev/cdrom /mnt/cdrom
# cd /mnt/cdrom
# ./VBoxLinuxAdditions.run
# reboot

Proxy: for proxy, add export http_proxy=proxy.url to .bashrc of root. If subversion was later installed, oen need to modifiy ~/.subversion/servers for lines containing http-proxy-host and http-proxy-port. When using sudo to update pacman, one need to add the following line after typing visudo: Defaults env_keep += "http_proxy https_proxy".

To share folders between host and Linux guest, one need to first setup the sharing in VirtualBox GUI. Then after installing Guest Additions as discussed above, the sharing can be enabled like below (assuming the shared folder name is bar and you want to mount it in your Linux guest directory /mnt/bar):

# mkdir /mnt/bar
# mount -t vboxsf bar /mnt/bar

Add additional user

# useradd -m -G audio,optical,storage,video,wheel foo
# passwd foo

Change foo to your desired name.

Run visudo to edit file /etc/sudoers. Uncomment the 1st line containing wheel to enable running root commands from wheel group. One may add lines like Defaults env_keep += "http_proxy" to pass environment variables.

Handling of security

Ru nthe following command: cp /etc/pacman.conf.pacnew /etc/pacman.conf. Apply all previously mentioned changes to /etc/pacman.conf to the overwrittine file. Then uncomment following line:

SigLevel = Optional TrustAll

Run pacman-key --init to initialize keyrings.

Cleanup unused packages

Since some packages are not useful to me, I remove them to avoid future waste of time and bandwidth to update them. Note that you may use pacman -Qe to list the explicitly installed packages. Warning: please make sure you do understand what you're doing: removing important system packages may break your system. As shown below, I only remove those packages related to file systems I'm not using.

# pacman -Rsn jfsutils reiserfsprogs xfsprogs

ABS

Run the following command:

# pacman -S abs

Edit /etc/abs.conf, For REPOS line, add ! before testing.

AUR helper

There are lots of AUR helpers, and I chose pacaur after trying various helpers (e.g. pacaur support proxy seamlessly pacman). To install pacaur, one needs to first install yajl and expac using pacman, then install cower and pacaur by running the following command.

$ sudo pacman -S yajl
$ wget http://aur.archlinux.org/packages/co/cower/PKGBUILD ; makepkg -si
$ wget http://aur.archlinux.org/packages/pa/pacaur/PKGBUILD ; makepkg -si

To install packages from AUR, simply run pacaur -S pkg.

SSHD

If one want to run SSHD server, one need to add sshd to DAEMON line of /etc/rc.conf. One may modify /etc/hosts.allow and/or /etc/hosts.deny. Default is that all connections are denied.

Xorg

Install Xorg by simply running pacman -S xorg. Accept the default (although there are many drivers not needed). Afterward, one need to install VirtualBox Guest Addition for video drivers, as discussed above.

Generally, there is no need to modify /etc/X11/xorg.conf since VirtualBox can handle the file for you when installing Guest additions. There is no need to specify screen resolutions since VirtualBox can seamless adjust it according to host resolution. However, if one wants to restrict available resolutions (e.g. to use StumpWM which is not compatible with VirtualBox's seamleass operation), one can add the following line in Section Screen, Subsection Display. Below example sets up two resolutions with 60 Hz refresh rate.

  Modes "1680x1050_60.00" "1440x900_60.00"

One may install package mesa-demos to benchmark OpenGL performance with glxgears.

For better font rendering, one may install freetype2-infinality, fontconfig-infinality, ttf-google-webfonts, and libxft-lcd from AUR.

GNOME

Install GNOME by typing the command pacman -S gnome. Then add dbus to DAEMONS array in /etc/rc.conf.

Add the following line to ~/.xinitrc:

#!/bin/sh

# Make sure it is at the beginnig of the file, especially before "exec gnome-session"
[ -f /etc/xprofile ] && . /etc/profile
[ -f ~/.xprofile ] && . ~/.xprofile
exec gnome-session

For VirtualBox, type the following to use GNOME 3:

# ln -s /usr/lib/xorg/modules/dri/vboxvideo_dri.so /usr/lib/dri
# pacman -S libltdl # Such reinstallation is needed.
$ gnome-shell --replace

To start GNOME, simply type startx.

I installed following packages in addition:

gconf-editor: - Edit GNOME settings
gnome-system-tools: - contains GNOME admin tools
gksu: - allows normal user to use system tools
gamin: - allows changes to files and directories to be detected immediately.
gnome-media-pulse: - enables volume control as tray notification
faenza-icon-theme: - cool icon theme
baobab: - disk usage

To select fonts suitable for LCD display, right click mouse on desktop, then select Change Desktop Background -> Font, select "Subpixel smoothing (LCDs)" for Rendering.

Update (2011-05-03): I installed login manager GDM by typing pacman -S gdm, and perform following changes to /etc/inittab:

comment line id:3:initdefault:
uncomment line id:5:initdefault:
comment line x:5:respawn:/usr/bin/xdm -nodaemon
uncomment line x:5:respawn:/usr/sbin/gdm -nodaemon

Audio

In VirtualBox settings for Audio Controller, I select Intel HD Audio. The sound car can be automatically detected by udev. So what needs to be done is to unmute some channels and let alsa store and restore mixer settings.

# pacman -S alsa-utils
# amixer set Master 90% unmute
# amixer set PCM 85% unmute
# aplay /usr/share/sounds/alsa/Front_Center.wav
# alsactl -f /var/lib/alsa/asound.state store

Finally, edit /etc/rc.conf and add "alsa" to DAEMONS array to store on shutdown and restore mixer settings on boot.

Customization and Applications

Note: this part is quite personal. The purpose I wrote it is mainly for documenting the steps so I myself may use it later.

Applications

Following is a list of applications installed by category. Some packages are only available from AUR and are marked by suffix [A].

Development tools: gdb, strace, cmake, valgrind, gprof2dot-git[A], bochs, qemu, mmixware [A], ghc, cabal-install, sbcl, racket, fluxus-git[A], squeak-vm[A], squeak-image[A], ruby, python, ipython, ipython2, pylint, pychecker, pyflakes, pep8[A], scipy, python2-pybrain [A], python2-nltk, wxpython, python-httplib2, python-pygame, ropemacs[A], matplotlib, libgnomeui, python2-pandas, django, nginx, gunicorn[A], postgresql, python2-psycopg2, auto-complete[A], jdk7-openjdk, visualvm[A], eclipse, eclipse-findbugs[A], android-sdk[A], android-ndk[A], android-sdk-platform-tools[A], emacs-android-git[A], scala, scala-docs, scala-sources, sbt, r, emacs-ess-svn[A], nasm, clojure, subversion, rapidsvn, ctags, git, perl-term-readkey, tig, tk, perl-libwww, mercurial, darcs[A], xmlstarlet, cconv[A], emacs-markdown-mode-git[A]
Documentation: texlive-most, pdftk[A], aspell-en, multimarkdown-git
Font: ttf-dejavu, ttf-inconsolata, terminus-font, wqy-bitmapfont, wqy-zenhei, wqy-microhei[A], ttf-arphic-uming, ttf-ms-fonts[A], ttf-vista-fonts[A], ttf-ms-fonts-zh_cn[A]
Multimedia: mplayer, mencoder, ffmpeg, codecs, cdparanoia, lame, cuetools, flac, shntool, wavpack, mac, mp3info, vorbis-tools
Web: lynx, chromium, flashplugin-prerelease, w3m, curl, amule
Utilities: gnupg, unzip, zip, p7zip
Graphics: gnuplot, inkscape, processing, graphviz, gimp, blender, imagemagick, darktable
Reader: djview4 , evince, kchmviewer, fbreader, calibre, pdf2djvu, catdoc, tesseract, tesseract-data-eng
Network: whois, nfs-utils, xinetd
Mathematics: maxima
Education: timidity++, solfege
X: xscreensaver
Fun: povray
Libraries: gsl, atlas-lapack[A], libmtp
Science: pymol, biopython, stellarium, celestia

Chinese Input

I install ibus as below:

# pacman -S ibus ibus-pinyin

Then add the following lines into ~/.xprofile:

export XMODIFIERS=@im=ibus
export GTK_IM_MODULE=ibus
export QT_IM_MODULE=ibus
ibus-daemon -d -x

Update (2011-01-06): switch from SCIM to ibus.

Emacs

For Emacs package management, el-get is interesting to try. The installation method is very unique and there is no need for an ArchLinux package.

Install scala-mode as below:

$ cd ~/.emacs.d/plugins
$ svn co http://lampsvn.epfl.ch/svn-repos/scala/scala-tool-support/trunk/src/emacs/ scala-mode

Get anything.el by wget http://www.emacswiki.org/emacs/download/anything.el.

Install following packages: auctex, slime-cvs, emacs-w3m-cvs, pymacs.

Install clojure related modes.

$ cd ~/.emacs.d/plugins
$ git clone https://github.com/technomancy/clojure-mode.git clojure-mode
$ git clone https://github.com/technomancy/swank-clojure.git
$ mkdir ~/.swank-clojure
$ cd ~/.swank-clojure
## Get three jars in https://github.com/technomancy/swank-clojure/blog/master/swank-clojure.el manually.

Install Hyperspec for Common Lisp

Run the following commands:

# wget ftp://ftp.lispworks.com/pub/software_tools/reference/HyperSpec-7-0.tar.gz
# tar xzvf HyperSpec-7-0.tar.gz
# mkdir /usr/share/doc/hyperspec
# mv HyperSpec !$

Stumpwm

First invoke sbcl, then type the following into REPL. Note that ASDF install is used other than AUR. Note that installation of trivial-gray-streams, flexi-streams, and cl-unicode might not be needed.

(require 'asdf)
(require 'asdf-install)
(asdf-install:install "http://common-lisp.net/project/cl-plus-ssl/download/trivial-gray-streams.tar.gz")
(asdf-install:install "http://weitz.de/files/flexi-streams.tar.gz")
(asdf-install:install "http://weitz.de/files/cl-unicode.tar.gz")
(asdf-install:install 'clx)
(asdf-install:install 'cl-ppcre)

When prompted by "Install where", it is recommended to select "Personal Installation" since it does not require root privilege. Note that some packages do not have GPG signature, so if SBCL drops you into debugger, simply select skip GPG check. If SBCL complaints and exited (due to in --disable-debugger mode), type the following after enter sbcl (sb-ext:enable-debugger) or add it to /etc/sbclrc as system initialize file for SBCL.

After installation of the dependencies, quit SBCL by type (sb-ext:quit) and run the following at CLI:

$ git clone http://git.sv.gnu.org/r/stumpwm.git stumpwm
$ cd stumpwm
$ ./autogen.sh
$ ./configure
$ make

After copy stumpwm to a directory in PATH, one can add "exec stumpwm" at the end of ~/.xinitrc. Then typing startx will bring up Stumpwm. Since I installed both GNOME and StumpWM, I decides to write two scrips to automate the changes to .~/.xinitrc. With these scripts, I can type startg for GNOME or starts for StumpWM.

Contents of script startg:

#!/usr/bin/env bash
sed -e 's/exec.*$/exec gnome-session/' -i ~/.xinitrc
startx

Contents of script starts:

#!/usr/bin/env bash
echo "exec stumpwm" > ~/.xinitrc
startx

Miscellaneous

For root, add one line in ~/.bash_profile to enable .bashrc

. $HOME/.bashrc

To run indexing daily, run crontab -e to add the following line (Update (2010-12-28): this step is not needed since updatedb is already added in /etc/cron.daily during installation of mlocate):

11 11 * * * updatedb

To keep boot messages on tty1 instead of clearing screen, add option for tty1 in /etc/inittab like below:

c1:2345:respawn:/sbin/agetty -i -8 38400 tty1 linux

Conclusion

After using Arch Linux for a long time, I have to say that I'm extremely satisfied. Your system may not be extremely fast as Gentoo boxes, but what you gain is significant: invaluable time.

My List of Android Apps

2010-03-13T11:39:00.003+08:00

I have been using HTC magic for 5 months. Although apps installed on top of cyanogenmod change week by week (if not day by day), I'd like to take a snapshot as shown below.

3banana: take quick notes. I sometimes use it to draft tweets which are sent out later when network connection is available.
Aldiko: ebook reader (specifically, an ePub reader). The builtin support of Feedbook catalog is fantastic.
Amazon: for quick lookup of prices.
APNdroid: control GPRS/EDGE/3G traffic.
ASTRO: file manager. Can also manage apps, show SD card usage, and display running processes/services.
Barcode Scanner: scan various codes. Good to scan QR code in Web to install apps.
Battery Monitor: show remaining battery percentage in notification area.
Bible KJV: the Bible.
CalWidget: highly customizable calendar widget. I just places one 4x4 widget at my left home screen. Much better than default widget.
Cavedroid: one addictive small 3D game.
EasyMoney: financial status manager.
FlipSilent: simply flip your phone to mute all sounds.
Google Pinyin: input method for Chinese.
Google Sky Map: cool app to view stars.
Google Voice: free SMS (English text only to non-GV users).
GPS Status: show GPS information as well as a compass.
handyCalc: a very powerful calculator. Serve as unit/currency converter as well.
HiDict: support offline dictionary.
iReader: I mainly use it to read transcripts (plain text format) of Tell Me More from NPR News.
Kids Paint: free drawing on screen. My daughter likes it.
Listen: podcast client. Integrate subscriptions with Google Reader now.
MarketEnabler: for rooted phone only. Useful for purchasing apps when your country is not in official support list.
My Tracks: I mainly use it for geotagging now.
NetCounter: look up data plan consumption instantly.
NewsRob: two-way synchronization with Google Reader. Grab contents for offline consumptions.
Places Directory: convenient to search nearby restaurants, banks etc.
Real Blackjack: try this one if you want to practice card counting...
RMaps: view maps offline.
Secrets: store your various passwords, account information here. Have strong security protection.
Shopper: shopping program from Google.
Shuffle: GTD tool.
Sipdroid: SIP client. Can be combined with Google Voice for free calls to US numbers.
SpacePhysics: challenging 2D physics game.
Swype: fantastic English input method.
Twidroid: Twitter client. Supports proxy API.
World Weather Clock: I now place two widgets on my home screen: one for home city, another for the destination I'm going to travel.

There are many cool apps that I installed and uninstalled later, because I seldom used them although they are awesome. For example, Layar, Shazam and Google Goggles are just some of them.

Upgrading SBCL

2009-01-01T21:31:00.003+08:00

Recently I upgraded SBCL from version 1.0.22 to 1.0.23. Then my window manager, Stumpwm refused to start. I have to solve the issue, otherwise I will start using console exclusively starting from 2009.

My first reaction was to reinstall stumpwm package. But when compiling, SBCL is complaining that there are version mismatch for stumpwm dependencies. I tried to solve the issue by reinstalling that package, but I met the same problem for its dependencies. I realized that I just stumbled upon dependency hell. I don't want to go through the same process of installing every CL package when I upgrade SBCL. So I need to find one simple solution. Indeed it exists: just delete all *.fasl files in SBCL's site directory (which is /usr/lib/sbcl/site under Arch Linux.), and then SBCL will rebuild all the installed packages. So the following command just solves the problem (assuming Arch Linux).

find /usr/lib/sbcl/site -name "*.fasl" -delete

Update (2009-2-11): do NOT run above command on the parent directory /usr/lib/sbcl, otherwise the fasl files bundled with SBCL will be deleted and many functionalities (e.g. ASDF) will break.

Adjusting Photos for Web Albums in Batch Mode

2008-12-24T20:37:00.001+08:00

I use Picasa Web Album to store my photos online. To save the precious storage at server, I have to change jpeg files before uploading them even for those taken by my old PowerShot S30 (which outputs photos with resolution 2048x1536, which is beyond the display capacity of most monitors today). To reduce file size, one normally need to reduce both resolution and image quality.

So how to adjust images in batch mode? There are various solutions of course. The one I take is to use the combination of find/xargs/mogrify (Note that mogrify modifies files in place. Therefore one may use convert instead of mogrify to preserve original files.) in Linux. Note that mogrify is one of ImageMagick utilities and may need separate installation depending on distribution. Following is my work flow when publishing images online.

Firstly, I select images with my preferred viewer gthumb. Images are rotated if necessary. During browsing, I copy the chosen files to another folder and run the following command in that folder:

find . -iname "*.jpg" | xargs mogrify -resize resize-option -quality quality-option

(I find the above command from here.)

Several notes regarding the above command:

resize-option could be either absolute (e.g. 800x600) or relative (e.g. 50%). For my S30, I use the latter which reduce the photo resolution to 1/4 of its original size.
quality-option is JPEG compression level. The larger the value, the better the quality, but the larger the file size. I often set the value as 60 to save space.

So for photos from my S30, I use the following command:

find . -iname "*.jpg" | xargs mogrify -resize 50% -quality 60

After running above command, photo file size can be reduced around 10 times. This means that I can put more images into my web album.

W(S)XGA+ Resolution in VirtualBox

2008-08-20T20:25:00.000+08:00

Note: this post is related to a workaround for one specific problem encountered by the author.

Recently I switched from coLinux to VirtualBox. VirtualBox provides guest addition which includes enhanced support for Video. Originally it worked fine for me. Due to unknown reason, the problem arises: I could not use resolution 1440x900 (WXGA+) or 1680x1050 (WSXGA+) any more. WXGA+ is the native resolution of my laptop, while WSXGA+ is the resolution of the external LCD when the laptop is placed in a dock. After tweaking for a long time, following is the solution I found so far (I installed Gentoo Linux as guest OS).

1. Revert video driver from VirtualBox to Vesa

This is done by editing /etc/X11/xorg.conf, change one line in Section Device from Driver "vboxvideo" to Driver "vesa".



2. Install support of 1440x900 and 1680x1050 to VESA BIOS

Add parameter vga=864 as Linux bootup parameter
(e.g. in /boot/grub/grub.conf) for resolution 1440x900,
or vga=865 for 1680x1050.

When Virtual machine is turned off, run the following two commands
at Windows command line prompt, assuming virtual machine is named
"Gentoo":

VBoxManage setextradata "Gentoo" "CustomeVideoMode1" "1440x900x24"
VBoxManage setextradata "Gentoo" "CustomeVideoMode2" "1680x1050x24"


Start virtual machine, select resolution 1440x900 or 1680x1050 for
console display. Note that the resolution for console is not
necessarily the same resolution for X, i.e. you can use 1440x900 for
console, and 1680x1050 for X.

3. Add modelines for resolution 1440x900 and 1680x1050.

I use gtf to generate needed modelines. For example for
resolution 1440x900 with 60 Hz refresh rate, I use the following
command:

$ gtf 1440 900 60


which give the following line:

  Modeline "1440x900_60.00"  106.47  1440 1520 1672 1904  900 901 904 932  -HSync +Vsync


I do not like the suffix _60.00, therefore what finally
end up in section Monitor of /etc/X11/xorg.conf is
(with addition of modeline for 1680x1050):

 modeline "1440x900" 106.47 1440 1520 1672 1904 900 901 904 932 -HSync +Vsync
 modeline  "1680x1050"  147.14  1680 1784 1968 2256  1050 1051 1054 1087  -HSync +Vsync


In addition, the two modes should be added in
section Screen of /etc/X11/xorg.conf as well, my
current setting is:

Section "Screen"
 Identifier "Screen0"
 Device     "Card0"
 Monitor    "Monitor0"
 DefaultDepth     24
 SubSection "Display"
  Viewport   0 0
  Depth     24
  Modes    "1680x1050" "1440x900"
 EndSubSection
EndSection


4. Select the resolution

Now the toughest part. You may have noticed that in
section Monitor, there are two lines about HorizSync
and VertRefresh. After experimenting, my conclusion is that
one should comment out them when using 1680x1050 while enable them for
1440x900. Weird.

Since I need to switch between these two resolutions frequently,
manually editing file /etc/X11/xorg.conf is boring. Therefore
I write one script to automate the task. I named the script
as xres and invoke it as sudo xres 1440 for resolution
1440x900 and sudo xres 1680 for 1680x1050. Following is its
content:

#!/bin/bash
case $1 in
    1440)
        sed -i 's/^#    HorizSync    31.5 - 64.3/       HorizSync    31.5 - 64.3/' /etc/X11/xorg.conf
        sed -i 's/^#    VertRefresh  50.0 - 70.0/       VertRefresh  50.0 - 70.0/' /etc/X11/xorg.conf
        ;;
    1680)
        sed -i 's/^     HorizSync    31.5 - 64.3/#      HorizSync    31.5 - 64.3/' /etc/X11/xorg.conf
        sed -i 's/^     VertRefresh  50.0 - 70.0/#      VertRefresh  50.0 - 70.0/' /etc/X11/xorg.conf
        ;;
    *)
        echo "Supported horizontal resolution: 1440 and 1680."
        exit
        ;;
esac



Experiencing Stumpwm
2008-07-24T00:43:00.003+08:00
What Emacs is to editors, Stumpwm is to window managers.

 --Bill Clementson (link)

Introduction

Recently I switched from GNOME to Stumpwm (wiki), which means
that I jumped out of a desktop environment to a simple window manager.
So far, I'm very satisfied with such a change and never looked back.
Stumpwm, as its website says, is a tiling, keyboard driven X11
Window Manager written entirely in Common Lisp. This definition
summarizes the reasons why Stumpwm is so suitable for me.

First, Stumpwm is a tiling, keyboard driven window
manager. This is very useful to boost productivity. When working, it
is desirable to minimize context switching. Tilting combined with
keyboard driven enables working with several applications
simultaneously as if your are dealing with one single program. Let me
give an example. As described in previous
post, with Emacs as development environment, it is easy to fire up
one browser within Emacs itself to preview blog post. However it is
painful to switch between Emacs and browser. Before using Stumpwm, I
am considering ways to integrate Emacs and Firefox together. With
Stumpwm, such dream is just trivial to fulfill: one can show
Emacs and browser side by side, with a few keystrokes to switch
between them. Everytime you make changes in Emacs and request the
results to be shown in Firefox, they are shown simultaneously. No more
need to leave your hand for mouse to click back and forth between
Emacs and Firefox. This gives you the feeling of integrated
environment. Note that I just use Emacs and Firefox as an example, and
such convenience is applicable for every application. Currently, the
problem is that I'm so accustomed to Stumpwm keystrokes that I somehow
confused the keystrokes of switching between windows in Stumpwm and
Emacs!

Second, Stumpwm is written in Common Lisp.  which
means that you can build Stumpwm with your favorite CL implementation
and you have a Lisp runtime when you work under Stumpwm. A powerful
programming language is just embedded within your window manager and
you can invoke it at any time. The other benefit is that you can
configure your window manager as you like, even when it is
running!

You may get a feeling on how Stumpwm works by watching this nice video.

Installation

Given the above lengthy introduction of Stumpwm, you may wonder how
to install this gem. Here we assume that you have some knowledge about
Common Lisp. Basically, installing Stumpwm is to compile it with your
preferred CL implementation, and tell your system to run Stumpwm as
your window manager.

Installing Stumpwm on Gentoo Linux is straightforward. Throughout
this section, we will assume that SBCL is the CL
implementation. Stumpwm website suggests turn off threading support in
SBCL (disable USE flag threads) for better performance. To
install, simply type emerge stumpwm. Note
that at the time of writing, there is also an ebuild called
stumpwm-cvs. Simply ignore it since it is actually a very old version,
not the bleeding edge version suggested by its name. Advanced users
might consider to get git version for latest cool features. 

There are mainly two ways to invoke Stumpwm. One is to run it by
calling SBCL, the other is to dump a core image containing Stumpwm
within SBCL and invoke that image. We will take the latter
approach. To proceed, first start SBCL by typing sbcl. Next
issue the following in REPL sequentially:

(asdf:oos 'asdf:load-op :stumpwm)
(sb-ext:save-lisp-and-die "stumpwm" :executable t
                          :toplevel #'(lambda () (stumpwm:stumpwm ":0")))


Next, put the generated executable stumpwm somewhere in
PATH (I put it under /usr/local/bin). Since I always start X Window by
typing startx, following command is used to use Stumpwm as
my window manager:

$ echo "exec stumpwm" >> ~/.xinitrc


Using Stumpwm

Configuration

All stumpwm configurations are stored in
file ~/.stumpwmrc, which is written in Common Lisp. Just
like .emacs, this file allows you to fully customize
Stumpwm. Following is my current configuration:

;;;; -*- Mode: Lisp -*-

(in-package :stumpwm)

;; Load swank.
(load "/usr/share/emacs/site-lisp/slime/swank-loader.lisp")
(swank-loader:init)
(define-stumpwm-command "swank" ()
  (setf stumpwm:*top-level-error-action* :break)
  (swank:create-server :port 4005
                       :style swank:*communication-style*
                       :dont-close t)
  (echo-string (current-screen) "Starting swank."))
(define-key *root-map* (kbd "C-s") "swank")       

;; Customize bars and modeline.
(setf *message-window-gravity* :center)
(setf *input-window-gravity* :center)
;; Turn on mode line.
(toggle-mode-line (current-screen) (current-head))
(setf *screen-mode-line-format* 
      (list "%w | "
            '(:eval (run-shell-command "date | tr -d '[:cntrl:]'" t))))

(set-prefix-key (kbd "C-i"))
(define-key *root-map* (kbd "c") 
  "exec urxvt +sb -fn \"xft:Bitstream Vera Sans Mono:pixelsize=20\"")

(define-stumpwm-command "firefox" ()
  "Run or switch to firefox."
  (run-or-raise "firefox" '(:class "Firefox")))
(define-key *root-map* (kbd "f") "firefox")


Some explanations of my configuration:


  Prefix key: I use C-i instead of
  default C-t. The reason is that C-t is used in
  Firefox to open a new tab and also in Emacs for transpose. Then why
  choose C-i? I'd like to admit that it is quite difficult
  to select a prefix key for Emacs user. Before settle down
  on C-i, I fired up Emacs to see whether there is any key
  binding C-x where x from a to z is not used by
  Emacs. Unfortunately (fortunately?), Emacs binds every
  combination. So I can only choose one prefix key which is easy to
  type and I uses infrequently in Emacs. Then C-i is
  selected. Note that you can send C-i to application like
  Emacs by typing C-i i. For the following sections, please
  replace C-i with your favorite prefix key.
  SLIME: the section staring with
  comments Load swank provides ways to load
  swank. Type C-i C-s to start swank. To connect to swank,
  simply run Emacs, and type slime-connect within Emacs,
  and type RET and RET to accept default host
  (127.0.0.1) and default port (4005). Then you can play with Stumpwm
  as you wish: change parameters, add your own functions etc. Note
  that I do not start swank automatically for security reasons. 
  Key bindings: I use C-i c to start
  console: urxvt instead of xterm. Note that I have
  also set the font for urxvt. In addition I have setup using C-i
  f to start Firefox in case Firefox is not started, or bring
  Firefox window to front if it is already running.


Key Bindings

Following is a list of key bindings I used frequently. For
simplicity, I have omitted the prefix key.


  ?: Stumpwm help
  ;: Run Stumpwm commands
  :: Send commands to Common Lisp interpreter.
  Space: Go to next window
  c: Run X terminal
  e: Run Emacs or raise it if it is already running
  f: Run Firefox or raise it if it is already running
  k: Kill current window
  g c: Create a new group
  g k: Kill current group
  g m: Move current window to a specified group
  g Space: Next group
  o: Focus shifts to next frame
  Q: Remove all splits
  s: Vertical split
  S: Horizontal split



Using PulseAudio for OSS Applications
2008-05-21T20:13:00.001+08:00
In my previous
post, I discussed how to use PulseAudio to enable sound for
coLinux. This works fine for programs like MPlayer, but has issues
with some programs e.g. Solfege.

The solution is simple: if the problematic applications have
support for OSS, then emerge them with OSS USE flag on. In
addition, PulseAudio should also be emerged with OSS USE flag
(to enable the building of padsp, a PulseAudio OSS wrapper, which will
be discussed below). Under Gentoo Linux, one way is to simply
add OSS USE flag to /etc/make.conf. Alternative way
is to enable the USE flag application by application. For example, to
enable OSS USE flag for Solfege, type the following:

# echo "media-sound/solfege oss" >> /etc/portage/package.use


When running these applications, prefix the command line
with padsp like the following:

$ padsp solfege


Note that you may need additional configurations in the application
 to use OSS for audio output.


HV30: Camcorder and Accessories
2008-05-05T21:22:00.002+08:00
I just bought Canon HV30 (Amazon, Review)
recently for my baby. Before buying HV30, I was agonizing over the
selection between HV30 and Canon HF10 (Amazon, Review)
(although I know that HF100 is better than HF10 from money point of
view since the internal 16GB flash drive of HF10 does not justify the
price difference, I do like the black paint job of HF10 and HV30).

Comparison of HV30 vs. HF10

So why I chose HV30 over HF10? The following is my comparison.


Features HV30 HF10 Comments

  Price
  MSRP price is $999 in US and
  ¥10580.00 (about $1514) in China
  MSRP price is $1099 in US and ¥14080.00 (about $2014) in
  China
  The price difference in China is quite significant, which is
  true even for street price.


  Performance
  1/2.7 in. sensor
  1/3.2 in. sensor
  According to the review,
HV30 has slightly better performance over HF10 thanks to larger
sensor, however the gain seems to be marginal for most cases.


  Functionalities
  Viewfinder, Zebra, Peaking
  
  


  Accessories
  Standard accessory shoe
  Canon proprietary accessory shoe
  


  Backup
  Tapes are cheap for backup
  Additional backup is needed since SDHC cards are expensive and
  will be reused.
  


  Community
  A mature community (looking at hv20.com
  for example)
  Situation will improve
  


  Form Factor
  88x82x138 mm (3.5x3.2x5.4 in.), 535 g (1.2 lb.)
  73x64x129 mm (2.9x2.5x5.1 in.), 380 g
  (13.4 oz)
  HF10 is small and light, which is ideal for traveling. Normally
  the camcorder which you takes out often is the most useful one.


  Media
  Tape
  SDHC card + internal Flash
  Flash card is really convenient: just like small DCs. No hassles
  for rewinding and no worry for overriding.


  Zoom
  10x optical zoom
  12x optical zoom
  


  Noise
  Tape noise can be heard in silent environment
  No such noise since flash card is
  used.
  



Accessories

What I have:


  Battery and charger: compatible ones
  Camera bag: Lowepro Edit 120+
  CPL filter: Kenko 43mm
  HDMI cable
  IEEE 1394 cable: Belkin 4-pin to 4-pin
  Lens cap
  miniSD: Transcend 2G. Not sure whether 4G could be used (the
  manual only states that up to 2G has been tested).
  Tape: Panasonic AY-DVM63PQ
  UV filter: Kenko MC-UV 43mm


For future purchase:


  35mm adapter
  Close-up lens: +1/+2/+4
  Mic: Canon DM-50, or combination of Rode Videomic and stereo
  mic. Maybe XLR adapters with XLR Mics?
  Neutral density filters: ND2/4/8
  Shoulder strap
  Steadicam Merlin
  Telephoto lens: Canon TL-H43 (any black version?)
  Tripod and fluid head: Manfrotto 190XPROB (tripod) + 701RC2
  (fluid head) + MBAG70 (bag)
  Video light: Canon VL-3
  Wide angle lens: Canon WD-H43 (any black version?)
  Wrist strap


Final Words

After over 1 month's usage of HV30, I'm pretty satisfied with
it. There is a lot of things for me to learn: how to shoot, how to
edit, just to name a few. But all the efforts are worthy when you view
the video clips produced from it.


Automatic Backup
2008-05-02T16:30:00.000+08:00
We need to backup our stuff in case that some disasters might
happen. One way is to backup to some external medias like tape, USB
drives, or CD/DVDs. However working with them is somehow tedious and
manual intervention is needed. People tend to be lazy therefore we are
reluctant to backup if the process is inconvenient. If we have one
additional machine with link in between (throughout this article, we
assume the remote machine is named as remotebox), we can setup
an automatic backup mechanism.

Overview

We use crontab to schedule rsync jobs to backup our files to
another machine. Since rsync is secured with SSH, to suppress the
password prompt, we have to setup SSH keychain.

Setup SSH Keychain

Generate Keys

This section mainly follows this nice
guide.

We use the DSA approach.

$ ssh-keygen -t dsa
$ scp ~/.ssh/id_dsa.pub user@remotebox


Then log in to remotebox and append the public key to
~/.ssh/authorized_keys file like so:

cat id_dsa.pub >> ~/.ssh/authorized_keys
rm id_dsa.pub


Install Keychain

Keychain is a nice package which prompt you for your passphrase
once you log into the system, and automatically provides passwords for
later SSH session. Note this incurs security risks (there are always
tradeoffs between security and convenience) therefore attention is
needed.

This part mainly follows this guide.

First install keychain by typing emerge keychain.

Then add following lines to your ~/.bash_profile.

/keychain id_dsa
. ~/.keychain/$HOSTNAME-sh


Setup Crontab Job

We can then setup our automatic backup system now. Since there are
almost infinite number of combinations of crontab and rsync patterns,
I just shown one example below (many interesting examples of rsync
usage can be found by typing man rsync).

0 9,16 * * 1-5 rsync -az -e ssh --delete ~/work/ remotebox:~/backup/


The above example synchronizes local directory ~/work to
remote directory ~/backup on host remotebox, on 9
a.m. and 4 p.m. of every working day. Note that I have used
option --delete, which will try to delete extraneous files
from destination directory. This can ensure that the destination
directory is an exact copy of source directory but it would be
dangerous if the destination directory contains some files already. So
test this option before you actually use it.


Switching Browsers in Emacs
2008-05-02T16:24:00.001+08:00
Recently, I have met one dilemma in Emacs. Since I'm using Emacs for my blog writing, Firefox is used for
previewing. Also as an Common Lisp user, I use emacs-w3m to read
HyperSpec. Here comes the problem: I can only set one browser
for browse-url-browser-function. How can I suit my
requirements simultaneously?

Fortunately, Emacs is highly extensible. I just write one simple
interactive function toggle-browser, which can toggle between
Firefox and emacs-w3m when pressing M-x
toggle-browser. Following is the code:

(defun toggle-browser ()
  "Toggle browser between Firefox and emacs-w3m."
  (interactive)
  (setq browse-url-browser-function 
        (if (eql browse-url-browser-function 'browse-url-firefox)
            'w3m-browse-url
          'browse-url-firefox))
  (message "%s" browse-url-browser-function))


Update: please look at the 1st comment from pedro for a better solution.


Using Imaxima with Texlive in Gentoo Linux
2008-04-10T00:37:00.002+08:00
Imaxima is an Emacs extension to interface with Maxima (see here for a nice
tutorial). To use it, one need a LaTeX distribution. However with
default Texlive installation in Gentoo, imaxima cannot work. Following
is a sample session:

(%i1) integrate(x,x);
LaTex error in: \ifracn{x^{2}}{2}


The problem here is that there is another package breqn
needed. Breqn is inlcuded in Texlive
package texlive-mathextra, which is not installed when
you emerge texlive. The package is also masked by default,
therefore you need to unmask it before emerging. Following is a list
of commands to install the package (substitute x86
with amd64 for x86-64 systems).

# echo "dev-texlive/texlive-mathextra ~x86" >> /etc/portage/package.keywords
# emerge texlive-mathextra


After installation, fire up your Emacs and enjoy (I)maxima!

Update: if you are not comfortable with the
default equation size (as in my case), you can add the following line
into your .emacs (adjust the number to suit your own taste):

(setq imaxima-scale-factor 2.0)



Copy and Paste between Windows and Linux
2008-04-08T21:36:00.001+08:00
Many people use Windows as primary working machine and login to
remote Linux/Unix (we will use Linux as shorthand afterwards)
boxes. There are times when we need to copy and
paste information between Windows and Linux. Below we are going to
discuss convenient ways to do so.

Tools

PuTTY and Xming are two popular programs to run in Windows host to
facilitate communication to Linux. PuTTY provides console connection
while Xming X Window connection. For Xming, Ensure you start Xming
with parameter -clipboard (which is enabled by default). Our
discussion below is focused on how to copy/paste within
PuTTY/Xming. Copy/paste for other Windows applications is quite
general (Ctrl+C and Ctrl+V) and should be
familiar to the reader, therefore omitted.

Ways

PuTTY

Copy to clipboard: click-and-drag to
highlight. Just select, no need to press any key.

Paste from clipboard: right mouse
button.

Xming

For Xming applications, copy/paste follows the X window
standard as discussed below.

Copy to clipboard: click-and-drag to
highlight. Same as PuTTY.

Paste from clipboard: middle mouse
button.


Installation of Gentoo Linux 2008.0 Beta 1 with LiveCD
2008-04-07T21:17:00.002+08:00
I just started yet another process of installing Gentoo Linux, and
following is my record of the installation step by step. Previously I
preferred to install from stage 1/3 following
this
guide. I decided to try LiveCD this time.

1. Boot the machine.

Download the 2008.0 LiveCD from here. Burn the CD
and boot the machine with it.

Caveat: in my case, the boot process is stalled. I
solved it (according to this
article) by appending kernel options during GRUB screen
(press e to edit and append all-generic-ide irqpoll
pci=nommconf).

2. Installation.

After boot, I click icon "Gentoo Linux Installation (GTK+)" in the
desktop.

Partitioning: I selected Recommended
Layout.

Local Mounts: accept the defaults without any
changes.

Timezone: Asia/Shanghai.

Networking: Dhcp is used. Appropriate host and
domain name are provided.

Users: Just add the regular user for daily
usage.

Extra Packages: I selected screen and slocate. In
my first installation I also selected xorg-x11, gdm, firefox
etc. However the installation simply failed when emerging
x11-apps/xinit (and I cannot rescue the system since even /etc/fstab
is not correctly setup), therefore my second try is quite
conservative.

Startup services: I selected sshd.

Other Settings: Although I have not installed X11
or Gnome yet, I selected as following:


  Display Manager: gdm
  Clock: local
  XSession: Gnome


3. Post Installation.

This section is similar as what I have described for coLinux
(see here),
but is modified specifically for a standalone Gentoo Linux
installation.

3.0 Tiny Cleanups.

After rebooting, perform the following steps. Note that if your
system was stalled as described before, you can use same trick in GRUB
screen and you should add the kernel options to /boot/grub/grub.conf
after login.

To avoid some warning, you might need to perform following
steps.

# mkdir -p /usr/local/portage


To change host name (according to Gentoo
Handbook), edit file /etc/conf.d/hostname, if you call
your coLinux machine as tux, then set the following line.

HOSTNAME="tux"


In addition, remove string .\O from
file /etc/issue to get rid of the
annoying unknown_domain in the welcome message "This is
host.unknown_domain ...".

3.1 Network

We have already specified using DHCP. It works but the
configuration files is using old syntax. Let's clean it up to avoid
future complaints. Edit file /etc/conf.d/net as
follows.

config_eth0=( "dhcp" )


3.1.1 Proxy

If you connect to Internet directly, you can skip this section.

To use proxy server, add the
following lines into /etc/env.d/99local:

http_proxy="http://proxy.server.com:8080"
ftp_proxy="http://proxy.server.com:8080"


Replace the port and domain name according to your situation.  Then
run:

env-update && source /etc/profile


3.2 Add additional locales

Modify file /etc/locale.gen, select appropriate
locales. For me, the locales are:

en_US.UTF-8 UTF-8
zh_CN.UTF-8 UTF-8


Then run command locale-gen.

3.3 Modify /etc/make.conf

This is specific for your computer type and other
factors. Following is my configuration (I'm using a Core 2 Duo
CPU). Please refer to Gentoo documentation for your own
reference. GENTOO_MIRRORS reflects the fastest mirrors for my
connection, as discussed below.

CFLAGS="-march=nocona -O2 -fomit-frame-pointer -pipe -fno-ident"
CXXFLAGS="${CFLAGS}"
CHOST="x86_64-pc-linux-gnu"
LDFLAGS="-Wl,-O1"
MAKEOPTS="-j3"
ACCEPT_KEYWORDS="amd64"
FEATURES="parallel-fetch"
LINGUAS="en zh zh_CN"
INPUT_DEVICES="keyboard mouse"
VIDEO_CARDS="i810"
PORTDIR_OVERLAY="/usr/local/portage"
GENTOO_MIRRORS="http://ftp.iij.ad.jp/pub/linux/gentoo/ http://ftp.kaist.ac.kr/pub/gentoo/"

USE_DEV="bash-completion doc emacs latex ruby sbcl source spell"
USE_HW="cpudetection mmx sse sse2"
USE_LIB="curl gd glibc-omitfp ncurses readline zlib"
USE_MM="aac alsa encode ffmpeg flac midi mp3 ogg pulseaudio quicktime theora xvid"
USE_PIC="gif jpeg png raw svg tiff xpm"
USE_SECURITY="crypt pam ssl tcpd"
USE_SW="bzip2"
USE_SYS="cjk nls nptl nptlonly opengl truetype unicode xinerama xml"
USE_X11="cairo gnome gtk X xft xorg"
USE="-* ${USE_DEV} ${USE_HW} ${USE_LIB} ${USE_MM} \
     ${USE_PIC} ${USE_SECURITY} ${USE_SW} ${USE_SYS} ${USE_X11}"


3.4 Synchronize Portage

Use either emerge --sync or emerge-webrsync
-v to update the portage.

3.5 Mirror selection

First run emerge mirrorselect. To select the fastest
mirror. I use the following command mirrorselect -D -H
-s2 to select the mirror. It means
that:



  -D: actual file will be downloaded from the mirror to test speed.
  -H: test http mirrors only.
  -s2: only select 2 mirrors.


After running the command, original /etc/make.conf will be
backed up as /etc/make.conf.backup and your selected mirrors will be
reflected in make.conf. Type mirrorselect -h for
details.

3.6 Update system

Run the following suites of commands (we need the -p argument to
check what the commands are supposed to do since they're somehow
"dangerous"):

emerge -uDNpv world
emerge -uDNv world
emerge --depclean -pv 
emerge --depclean -v
revdep-rebuild -pv
revdep-rebuild -v


Caveat: if you encounter circular dependency when
emerge -uDNv world, try to remove gtk USE flag
from /etc/make.conf. After successful emerging, add
gtk flag again and run emerge -uDNv world again. 

After update, run dispatch-conf to update the
configuration files.

3.7 Install X11 and GNOME.

Run command emerge xorg-x11 to install X11. Then
use xorgcfg -textmode to configure X server.

I'm using a LCD with resolution of 1680x1050, which is not listed
in standard configurations. To use it, first run gtf 1680 1050
60, copy the output to the Monitor section
of /etc/X11/xorg.conf, and modify section Screen to
the resolution 1680x1050.

For GNOME, I prefer to install gnome-light to avoid the gigantic
full GNOME installation. To do so, simply run emerge
gnome-light.

If one use startx to run X11, one can simply
type echo "exec gnome-session" > ~/.xinitrc to configure
so.

To make gdm the default login screen, run the following commands:

# emerge gdm
# rc-update add xdm default


And then edit /etc/conf.d/xdm, changing DISPLAYMANAGER
to gdm.

3.8 Install Other programs.

This section is left empty intentionally :-)



Conclusion

It is quite convenient to install with LiveCD. There are some
hassles during installation, but I assume the reason is that I'm using
a beta version. Since beta version is not stable, my suggestion is to
install minimal components therefore you can quickly finish the
installation and boot from hard drive.

Although GRP install is not so optimal, the pre-compiled packages
should be quite close to optimal ones for 64-bit machines. Also as a
Gentoo user, I'm always in the process of customization the OS to suit
my needs, therefore a not-so-ideal-initial-setup is not an issue. In
summary, livecd approach can save a lot of time, with almost similar
end result as installing from stage 1/3.


Ripping CD to FLAC in Gentoo Linux
2008-04-07T21:15:00.000+08:00
This post is just a simple note, inspired from here.

First, install cdparanoia and flac:

# emerge cdparanoia flac


Next, issue the following commands (I deleted the original WAV
files after conversion). All tracks are extracted and converted to
FLAC format.

# cdparanoia -B
# find . -name "*.wav" -print0 | xargs -0 flac
# rm *.wav


Then enjoy the music with your favorite player. Since I'm using
mplayer, I call Ruby to generate the playlist and invoke mplayer with
it (in the 1st line below, the last track number is 16. Change it
according to your own situation).

$ ruby -e '(0..16).map{|i| printf("track%02d.cdda.flac\n", i)}' > pl
$ mplayer -playlist pl



Enable Sound for coLinux
2008-04-02T20:36:00.000+08:00
In my previous post about installing
coLinux with Gentoo, audio part is not touched. Here comes the
solution on how to use PulseAudio to bridge coLinux to sound
world. This is adapted from here
with contents modified for Gentoo Linux. 

Windows side

We need to install PulseAudio server on Windows. Frist
download binaries for Windows from here. Extract to one
directory (c:\bin\pulseaudio in my case).

In the directory of the binaries, create a text config file named
default.pa with the content:

load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1;192.168.0.0/24
load-module module-esound-protocol-tcp auth-ip-acl=127.0.0.1;192.168.0.0/24
load-module module-detect


We start PulseAudio automatically when coLinux starts, by adding
the following line to the coLinux configuration file:

exec0=c:\bin\pulseaudio\pulseaudio.exe


Linux side

Install and configure PulseAudio client

Install PulseAudio by emerge pulseaudio. Then
edit /etc/pulse/client.conf to set the address of the Windows
host that runs the PulseAudio server:

default-server = 192.168.0.1


where 192.168.0.1 is the IP address of the Windows
host.

Make sure to add USE flag alsa
to /etc/make.conf. If you just add this USE flag, update your
system with emerge -uDNv world. ALSA would be automatically
emerged.

Install alsa-plugins

In addition, we should install alsa-plugins:

# echo "media-plugins/alsa-plugins pulseaudio" >> /etc/portage/package.use
# emerge alsa-plugins


Edit ~/.asoundrc with the following contents.

pcm.!default {
    type pulse
}

ctl.!default {
    type pulse
}

pcm.pulse {
    type pulse
}

ctl.pulse {
    type pulse
}


Test

As a final step, you can test with an ALSA player:

aplay /usr/share/sounds/alsa/Front_Center.wav


You should hear a voice saying "Front Center". Enjoy!


Install Gentoo with coLinux
2008-03-16T14:53:00.006+08:00
coLinux is gaining momentum as a way to run Linux programs on
Windows, and I decided to try it. As a user
of Gentoo, my first choice is to use Gentoo with coLinux. The
following description documents what I have done to run Gentoo
cooperatively in Windows laptop. I mainly follows up the Gentoo Wiki Howto article
and other coLinux resources.

1. Installation

First download the latest coLinux snapshot (you can
also get it from SourceForge). The
file I used is coLinux-0.7.2.exe from SourceForge. Run the
installer. Some notes during installation:


  In screen Choose Components, leave the default settings
  on (i.e. selecting all components), but uncheck Root FileSystem
  image download (we will download it separately).
   In addition, change the Destination folder to
  c:\bin\coLinux (note that all the description below assumes
  coLinux is installed into this directory. If you prefer other
  directory, please modify accordingly in steps below). 
  Installer prompts to download and install WinPCap separately,
  but my network configuration does not need WinPCap therefore I don't
  install it.


Then download Gentoo-colinux-i686-2007-03-03.7z from SourceForge,
extract the archive into c:\bin\coLinux, with a
gentoo subdirectory created during extraction. Copy file
gentoo.conf in gentoo to the parent directory and
modify it as follows:

kernel=vmlinux
cobd0=C:\bin\coLinux\gentoo\gentoo-root
cobd1=C:\bin\coLinux\gentoo\linux-swap
root=/dev/cobd0
hdc=\Device\Cdrom0
initrd=initrd.gz
mem=1024
eth0=tuntap
cofs0=c:\linux


Some explanations of the above file, details will be covered in
later sections.


  For mem, I set it to 1G. Choose according to your own
  situation.
  For network, I only select TAP driver.
  I shared Windows folder c:\linux to coLinux.
  CD/DVD-Drive is mounted. 


To test drive, open a command prompt, change to the directory
c:\bin\coLinux, and run the following command:

colinux-daemon @gentoo.conf


coLinux console should run. If there is something wrong, please
check previous steps. After some time, you are prompted for log in.
You can now login as root with password. Change your password
immediately.

Congratulations! You just successfully run Gentoo in coLinux! You
can now fool around with the system. Type halt when you are
tired. There is still a long road ahead to fully harness the
power. Following is two optional steps, but highly recommended.

Run coLinux during system startup

First, we need to install coLinux as a service. Open a command
prompt, change to the directory c:\bin\coLinux, and run the
following command:

colinux-daemon.exe @gentoo.conf --install-service "CoGentoo Linux" 


Then open Control Panel, first select Administrative
Tools, then Services, click service CoGentoo Linux, and
change its Startup type to Automatic.

Enlarge the image file

The original image size is 2G. This might not be sufficient. To
enlarge it, you need to download the tools from here. Extract the
archive and run file toporesize.bat. Use the program to
resize file c:\bin\coLinux\gentoo\gentoo-root to whatever
size you want. Make sure you uncheck "resize file
only no resize2fs".

2. Configuration

2.1 Timezone

Since I'm located in Beijing, I set the corresponding info as
follows. The related configuration files is
/etc/conf.d/clock. I changed two lines as follows.

CLOCK="local"
TIMEZONE="Asia/Shanghai"


Also run command ln -fs /usr/share/zoneinfo/Asia/Shanghai
/etc/localtime.

It is interesting that Beijing cannot manage to snap one place
inside /usr/share/zoneinfo/Asia.

2.2 Network

Based on coLinux
wiki article.

2.2.1 One network interface

This configuration only enable TAP, which is used to enable both
the high-speed private connection between Windows host and Linux
guest, and also to bridge the connection to Internet. One drawback of
this setup is that when you Internet connection changes (e.g. from
ADSL to WiFi, you have to adjust bridging and some parameters
manually).

File gentoo.conf discussed above already contains the
setup for coLinux. Next steps are as follows.

On hosting OS (Windows), configure TAP-Win32 Adapter V8
(coLinux) with following properties (make sure to leave
Default Gateway as blank):

Ethernet adapter:

        Connection-specific DNS Suffix  . :
        Description . . . . . . . . . . . : TAP-Win32 Adapter V8 (coLinux)
        Dhcp Enabled. . . . . . . . . . . : No
        IP Address. . . . . . . . . . . . : 192.168.0.1
        Subnet Mask . . . . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . . . . :


We need to bridge the Internet connection with TAP interface. For
example, assume you're using an ADSL PPPoE connection. In Windows
host, select Control Panel -> Network Connections, right
click the PPPoE interface, and select Properties. In tab
Advanced, for Internet Connection Sharing, check
Allow other network users to connect through this computer's
Internet connection, and for the Home networking
connection, select the TAP interface (e.g. Local Area Connection
2). When Windows prompts that TAP interface IP address will be set to
192.168.0.1, choose OK.

Under coLinux, edit file /etc/conf.d/net as follows.

config_eth0=( "192.168.0.20/24" )
routes_eth0=( "default via 192.168.0.1" )
dns_servers_eth0=(" xxx.xxx.xxx.xxx " )


Please change the DNS server information (shown as xxx above) to
those obtained in windows (e.g. via ipconfig).

We have to emphasize here that in this setup, Linux guest has IP
address 192.168.0.20 (this is arbitrarily selected, could be other
numbers like 192.168.0.x when 2 <= x <= 254), and Windows host has IP
address 192.168.0.1 interfacing Linux (of course Windows host has
external IP addresses as well).

2.2.2 For two network interfaces

Note this part is NOT compatible with other sections. The purpose
of this section is only to document alternatives to above solution. If
one interface solution is fine for you, you can skip this section.

This configuration enables both SLiRP and TAP connections. SLiRP is
used to connect outside world while TAP enables the high-speed private
connection between Windows host and Linux guest, which is desirable
for X protocol. The benefits of this configuration includes improved
security and that SLiRP can automatically use current Windows Internet
connection for outgoing connections (i.e. you do not need to enter DNS
server information) without reconfigurations. This works fine for
Wireless LANs, but I did meet problems for ADSL and finally decided to
use TAP only.

Anyway, let's look at how to setup two network interfaces.

First, we need to modify the aforementioned file
gentoo.conf located in coLinux directory. Change the line
eth0=tuntap with two lines as below.

eth0=slirp
eth1=tuntap


Then edit file /etc/conf.d/net on Linux guest. This
enables both SLiRP and TAP.

config_eth0=( "dhcp" )
config_eth1=( "192.168.37.20/24" )


We then need to setup DHCP client as following:

emerge dhcpcd
rc-update add dhcpcd default
/etc/init.d/dhcpcd start


Since only eth0 device is generated, we need to generate
eth1 device by 

cd /etc/init.d
ln -s net.lo net.eth1


On hosting OS (Windows), configure TAP-Win32 Adapter V8
(coLinux) with following properties (make sure to leave
Default Gateway as blank):

Ethernet adapter:

        Connection-specific DNS Suffix  . :
        Description . . . . . . . . . . . : TAP-Win32 Adapter V8 (coLinux)
        Dhcp Enabled. . . . . . . . . . . : No
        IP Address. . . . . . . . . . . . : 192.168.37.10
        Subnet Mask . . . . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . . . . :


2.2.3 Proxy

If you connect to Internet directly, you can skip this section.

To use proxy server, add the
following lines into /etc/env.d/99local:

http_proxy="http://proxy.server.com:8080"
ftp_proxy="http://proxy.server.com:8080"


Replace the port and domain name according to your situation.  Then
run:

env-update && source /etc/profile


2.3 Add additional locales

Modify file /etc/locale.gen, select appropriate
locales. For me, the locales are:

en_US.UTF-8 UTF-8
zh_CN.UTF-8 UTF-8


Then run command locale-gen.

2.4 Mirror selection

First run emerge mirrorselect. To select the fastest
mirror. I use the following command mirrorselect -D -H
-s2 to select the mirror. It means
that:


  -D: actual file will be downloaded from the mirror to test speed.
  -H: test http mirrors only.
  -s2: only select 2 mirrors.


After running the command, original /etc/make.conf will be
backed up as /etc/make.conf.backup and your selected mirrors will be
reflected in make.conf. Type mirrorselect -h for
details.

2.5 Modify /etc/make.conf

This is specific for your computer type and other
factors. Following is my configuration (I'm using a Core 2 Duo CPU on
32 bit Windows). Please refer to Gentoo documentation for your own
reference. GENTOO_MIRRORS reflects the fastest mirrors for my
connection, so you may skip that line if your have already performed
mirrorselect above.

CFLAGS="-march=prescott -O2 -fomit-frame-pointer -pipe -fno-ident"
CXXFLAGS="${CFLAGS}"
CHOST="i686-pc-linux-gnu"
LDFLAGS="-Wl,-O1"
MAKEOPTS="-j2"
ACCEPT_KEYWORDS="x86"
FEATURES="parallel-fetch"
LINGUAS="en zh"
USE="-* auctex bash-completion bzip2 cjk crypt curl doc emacs gd gif glibc-omitfp gtk \
     javascript jpeg mmx mozilla ncurses nls nptl nptlonly opengl pam png readline \
     ruby sbcl source spell sse sse2 ssl svg tcpd tiff truetype \
     unicode X xft xml xorg xpm zlib"
PORTDIR_OVERLAY="/usr/local/portage"
GENTOO_MIRRORS="http://ftp.iij.ad.jp/pub/linux/gentoo/ http://ftp.kaist.ac.kr/pub/gentoo/"


2.6 Update system

Since our original system is somehow outdated, we need to update
it. First run emerge --sync or emerge-webrsync
-v to synchronize portage, then run the following suites of
commands (we need the -p argument to check what the commands are
supposed to do since they're somehow "dangerous"):

emerge -uDNpv world
emerge -uDNv world
emerge --depclean -pv 
emerge --depclean -v
revdep-rebuild -pv
revdep-rebuild -v


Caveat: if you encounter circular dependency when
emerge -uDNv world, try to remove gtk USE flag
from /etc/make.conf. After successful emerging, add
gtk flag again and run emerge -uDNv world again. 

After update, run dispatch-conf to update the
configuration files (you need to avoid the update of
/bin/setfont. If you accidentally updated the file, you can
remedy the situation as discussed below):

Caveat: if during booting, you meet the error
message putfont: PIO_FONT: Function not supported, Solve the
problem as follows (as discussed here):

First, run command mv /bin/setfont /bin/setfont.old

Create a new file /bin/setfont with the following content:

#!/bin/bash

if ! uname -r | grep -q -e "-co-"
then
        /bin/setfont.old $@
fi


and make it executable by running chmod +x /bin/setfont

3. Run X

X.org is already installed in coLinux machine when we update the
system as discussed in section 2.6 (we have include X USE
flag). Therefore the remaining steps are just to install X server in
Windows host.

We choose Xming considering it is lightweight and widely used. To
install Xming, Download Xming
installer, font
installer and Xming-tools-and-clients. You
may use Xming-mesa
installer to replace Xming installer for stable OpenGL operation (only
do so if you meet problems with Xming installer).

My settings during installation of Xming are as follows:


  Xming
    
      Destination directory: changed to c:\bin\Xming.
    
  
  Xming-fonts
    
      Destination directory: changed to the same directory as
      Xming (c:\bin\Xming)
      Fonts to be installed: select according to your own taste.
    
  
  Xming-tools-and-clients extract the zip file of
  Xming-tools-and-clients to the directory where Xming is installed
  (c:\bin\Xming in this case).


Settings on Windows host

For file x0.hosts in Xming directory, make sure the IP
address of coLinux machines (192.168.0.20) is added.

If you want to run the tools and clients bundled with Xming in
Windows host, you need to type set DISPLAY=127.0.0.1:0 in
your Windows host.

Following steps are used to enable Windows fonts to be used by X
application. This step is optional.

Open a command prompt window, change to directory
c:\bin\Xming, and type the following commands:

mkfontscale C:/WINDOWS/Fonts
mkfontscale -b -s -l C:/WINDOWS/Fonts


Make sure that directory C:\Windows\Fonts appeared in the
file font-dirs in Xming directory.

On coLinux machine

Add the following line into /etc/profile.

export DISPLAY=192.168.0.1:0


After start Xming (preferably to start it automatically when
Windows start), you can simply invoke any command inside Linux console
like:

xterm &


4. Miscellaneous

Change host name

According to Gentoo
Handbook.

Edit file /etc/conf.d/hostname, if you call your coLinux
machine as tux, then set the following line.

HOSTNAME="tux"


Edit file /etc/conf.d/net, if you call your domain as
homenetwork, then set the following line.

dns_domain_lo="homenetwork"


Remove string .\O from file /etc/issue to get rid
of the annoying unknown_domain in the welcome message "This
is host.unknown_domain ...".

Create regular user accounts

With the following command, I created a new user named foo as a
powerful user (with the ability to su to root and also invoke some
portage related commands). Pleas substitute foo above with
your desired user name.

useradd foo -m -G users,wheel,portage
passwd foo


Access Windows folder

When we edit gentoo.conf above, we have already enabled
coLinux to share folder c:\linux. To make our regular user to access
this directory in Linux, edit file /etc/fstab and add the
following line:

cofs00  /home/foo/windows  cofs  uid=foo,gid=foo,dmask=0755,fmask=0644 0 0


The above line will enable the Windows folder to be shared in Linux
as a folder /home/foo/windows. You can modify above line for your own
user.

Additional programs

Following is a list of commands to install my own favorite
programs. Your situation would be of course different.

# Some system utilities
emerge gentoolkit slocate

# Development tools
echo "dev-lang/erlang hipe" >> /etc/portage/package.use
emerge aspell ruby sbcl erlang dev-util/git maxima

# Gfx (GLEidescope is one of my favorite XScreenSaver)
emerge inkscape blender xscreensaver

# Netowork
emerge mozilla-firefox

# X tools
emerge xlsfonts xfontsel


Before emerge texlive, I have to add a bunch of keywords
for dependencies in /etc/portage/package.keywords as
follows.

app-text/texlive ~x86
app-text/texlive-core ~x86
dev-texlive/texlive-metapost ~x86
dev-texlive/texlive-basic ~x86
dev-texlive/texlive-documentation-base ~x86
dev-texlive/texlive-psutils ~x86
dev-texlive/texlive-langcjk ~x86
dev-tex/cjk-latex ~x86
dev-texlive/texlive-documentation-english ~x86
dev-texlive/texlive-genericrecommended ~x86
dev-texlive/texlive-latexrecommended ~x86
dev-texlive/texlive-latex ~x86
dev-texlive/texlive-texinfo ~x86
dev-texlive/texlive-latex3 ~x86
dev-texlive/texlive-htmlxml ~x86
app-text/jadetex ~x86
dev-texlive/texlive-fontsrecommended ~x86
app-text/dvipdfm ~x86
dev-texlive/texlive-documentation-chinese ~x86
dev-texlive/texlive-langmanju ~x86


Use CVS version of Emacs

Run the following commands:

echo "app-editors/emacs-cvs ~x86" >> /etc/portage/package.keywords
emerge emacs-cvs


If you want to use this bleeding-edge version only, you
can uninstall the previous version of Emacs (if you have installed)
and type:

echo "virtual/emacs ~x86" >> /etc/portage/package.keywords


Otherwise (i.e. you have multiple versions of Emacs), when you
emerge packages requiring Emacs, a stable version
(e.g. v22.1) will be installed. For the multiple-version-installation,
you can use eselect emacs list to see a list of available
version. To use Emacs 23 just installed, you can type eselect
emacs set emacs-23. For details, please consult here.

Emacs extensions

I run the following commands to install a few Emacs
extensions. Note that in Gentoo, many extensions (e.g. those related
to development) are automatically installed for you when you emerge
the related tools and enable emacs USE flag.

echo "app-emacs/gentoo-syntax ~x86" >> /etc/portage/package.keywords
echo "app-emacs/imaxima ~x86" >> /etc/portage/package.keywords
emerge htmlize imaxima app-emacs/gentoo-syntax keywiz


Enable SSH server

You may want to enable SSH access to your coLinux machine. There
are some benefits. Examples are shown below (assuming PuTTY is
used):


  More flexibilities to configure the client (e.g. pretty fonts)
  and nice scrollbars.
  The title of PuTTY indicates what coLinux is doing (such
  information might be useful during a long emerge process).


To start SSH server, type the following commands.

rc-update add sshd default
/etc/init.d/sshd start


When you use PuTTY client, you should fill 192.168.0.20
as the host address to utilize the high speed internal connection.

GTK configrations

Change the default GTK+ font. Edit file ~/.gtkrc-2.0, add
the following line, and change the font name and size to your
preferred one.

gtk-font-name = "Arial 15"


Mount CD

Simply type the following

# mount -t iso9660 -o ro /dev/hdc /mnt/cdrom




Final Words

coLinux is an interesting way to run Linux applications in Windows
host. One drawback of coLinux is that the daemon process is pinned to
one processor only. This avoids some bizarre issues, however it does
not utilize the potentials of modern multi-core systems. This is
disappointing especially for a Gentoo user who requires lots of
computation power. Hope the situation could be improved in the
future.

Update: please refer this post on how to enable sound.


Reading List
2008-01-17T12:33:00.094+08:00
My previous post discussed my thoughts on how to read programming books, here comes my reading list of programming/computer science books. The books I have completed reading after this post are listed for each year, afterwards come the books I am reading and those I plan to read (all books I have completed before this post is not listed here). Note that this is a living document.
         脂砚斋批评本红楼梦(上下)
尘埃落定
  

三体
三体II
三体III
三体X
球状闪电
超新星纪元
边城
流浪地球
白垩纪往事
作文入门
 

 
追踪1789法国大革命
叶嘉莹说初盛唐诗:迦陵说诗


 

我的阿勒泰


Reading
Concrete Mathematics 
Structure and Interpretation of   Computer Programs
Lisp in Small Pieces
Programming   Pearls
What Is Mathematics
The Feynman Lectures   on Physics
Principles of Economics
Mathematics and Plausible Reasoning (Volume I)
Operating Systems Design and Implementation (3rd Edition)
Professional Assembly Language
Fundamentals of Wireless Communication
Introduction to Algorithms (2nd Edition)
Essentials of Programming Languages (3rd Edition)
One Two Three . . . Infinity
The History of the Decline and Fall of the Roman Empire, Vol. 1
Aha! Insight
Artificial Intelligence: A Modern Approach (3rd Edition)
Practical Common Lisp
围棋死活大全
海子诗全集
To Read
Operating System Concepts (7th Edition)
Compilers: Principles, Techniques, and Tools (2nd Edition)
Computer Graphics: Principles and Practice in C (2nd Edition)
Art of Computer Programming, Volume 1: Fundamental Algorithms (3rd Edition)
Astronomy Today (6th Edition)
Walden
Mathematical Thought from Ancient to Modern Times, Vol. 1
A History of Western Philosophy
The Seasoned Schemer
Types and Programming Languages
Concepts, Techniques, and Models of Computer Programming
Information Theory, Inference & Learning Algorithms
Psychology
Genes IX
Update (2008-8-18): started to add books other than CS/programming, e.g. mathematics, physics, literature, communications.
Update (2009-2-25): replaced table format with lists (lists with year heading consists books completed in that year), partly because lists are easier to update, but mainly because that I tend to sneak more books into reading queue when no free "slots" available, which makes the table format itself somehow "cheating".
Update (2009-3-13): started to use Amazon widget; correct the 1st paragraph to reflect the status of reading.


Read Programming Books
2008-01-16T12:39:00.001+08:00
Although learning programming can be achieved via online tutorials,
reading books is still the preferred way for systematic learning (see
some discussions here,
here,
and here
from author's point of view). Following list is gathered along my
adventure on reading programming books, especially on programming
language books (for books not requiring
active participations, it is recommended that you follow advice
from Charles Petzold). Some suggestions are easier to be said than
to be done, therefore the list is also a reminder to myself.

1. Select the right book

Reading a programming book requires enormous time and
energy. Before embarking on the hundreds-hour-adventure, it is
justified to spend sometime to select the correct path. Sometimes
starting reading an excellent book itself is an achievement. So which
book to read? The simplest solution is to search in Google or Amazon
and select those with enthsiastic reviews.  Google/Amazon are always
handy since you can get more details/reviews on books. There are
alternatives of course, as we will discuss below.

If you just want to read great programming books without
any specific topics, you are lucky since this important question has
already been discussed again and again. For example, you may refer to
this Reddit
thread, or you can consult the opinions of some outstanding
programmers/bloggers (e.g. Steve Yegge's recommendations here and
here,
Joel
Spolsky's advice, and Jeff
Atwood's list).

If you do have some topics in mind (e.g. one particular programming
language), there are various ways in addition to Google/Amazon
approach.


  Lookup in Wikipedia. Typically for one programming language,
  there will be one related article. At the end of the article, there
  is one References section, where you can find some
  interesting links to books. 
 Consult the FAQ of the language newsgroup. Normally, language X
 has one corresponding newsgroup like comp.lang.X. Generally the FAQ
 (sometimes quite outdated) of the newsgroup contains some book
 recommendations.
 For some languages with official website (e.g. Haskell, Perl, and Python), you can easily find book
 recommendations in the site.


Let's name a few commonly recommended books for some programming
languages: SICP (a.k.a. Wizard Book) for
Scheme, Practical Common Lisp for Common Lisp,
Programming Ruby (a.k.a. The PickAxe Book) for Ruby, and
Javascript, the Definitive Guide (a.k.a. The Rhino Book) for
the Next Big Language.

2. Setup programming environment and prepare related resources

You can't learn programming without getting your hands dirty. To study one
programming language, you have to install necessary package(s).
"Modern" programming books (e.g. Practical Common Lisp,
Programming Ruby, Javascript, the Definitive Guide,
and Programming Erlang) typically have one chapter getting
you started. If your book does not contain such part, you can always
consult online tutorials to setup the environment.

Typically the package contains some kind of editor or IDE for
developing. You need to familiarize yourself with them either by
reading your book or tutorial. For Emacs users, you can install
related mode and simply fire up Emacs.

If the book is not so cutting-edge, you can find abundant resources
in the web: source code, discussion on exercises, and even video
lectures. You can bookmark or download these resources for your future
reference. SICP is an excellent example here: great video
lectures, and nice wiki to
discuss solutions to exercises.

3. Practice, practice, and practice

You can't learn a language without sustained practice. We will
focus on the examples and exercises contained in the book here. 

When you read one example, simply reading is not
enough. It is better if you type the example and run
it. Note: type, not copy & paste. The reason is the same
as when you write programs. After compilation, you think your code has
done what it's supposed to do. But typically you need several iterations to make
it right. Similar thing happens for reading. You think you understand
the code on paper, but actually you do not. You should type it in and
run it to really understand it. When you type, you can think about the
meaning of the code, syntax and idioms associated simultaneously. A
more paranoid yet effective way is that you first read the example,
and then enter it without even referring to the book. You then run the
code, analyze the results, and compare your code with the example
supplied in the book.

Now for exercises. Do them all if you can. Excellent books come
with excellent exercises, if any. You could gain more insight when you
employ the techniques you just learned. (If you have any doubt on the
value of exercises, you can look at Steve
Yegge's example on how doing exercises can change a person's view
about a language.) If you cannot solve one problem with
serious try, you can leave it for a while and attack it
later. If you really cannot handle it, you can refer to the solutions,
which you can typically find online. Believe me, you can easily find
the answers to these hard problems of excellent books in the web.

4. Develop hobby project

When you have already read several chapters of the book and feel
comfortable to write a few small programs with the language you just
learned, you may consider to setup some hobby projects. You can use
the project to automate some day-to-day tasks, either in home or at
work. Or you may try to implement/interface some (emerging) cool
things (e.g. Google Chart
API or Ray
tracing) with the language you are learning. Make sure the skills
to complete the project match the skills you just learned. You may
meet some problems you cannot handle with the skills you just
acquired. Don't panic. Just peep the later chapters of the book you
are reading, or Google around. Try to finish the project if you can
(and then you can blog about it if nobody has not done so or your way
is quite interesting). If you cannot finish it, you can leave it for a
later attempt. You may try several such projects when you progress in
the reading. The further you progress, the more ambitious task you can
try. Such hobby project itself can be viewed as extended exercises,
but designed by you, instead of the author.

(Note: this section is largely influenced by a nice article/post
related to reading On Lisp. Unfortunately I cannot find the
URL now.)

5. Never give up

The last but not the least advice is that you should read the book
from the beginning to the end. Spending a lot of time on one book but
giving it up when approaching say one third of it is just wasting
time. Since you only touched the surface of the book, which is easier
to learn and also easier to forget. Authors arrange the books
in such a way that you could linearly read along, which typically
means that advanced topics come later. You may get stuck with one
chapter and cannot understand the topics discussed there. At this
point, don't give up. Remember that you can only achieve a higher
level of understanding of one language/technique if you can understand
the difficult part of it. Just read it, understand it, try it, or
Google around to find different (maybe better) treatment of the
topic. Attack this gnarly
problem and you will gain lots from it. You have now learned some
unique things of the language, you can now look at the language in a
different yet more insightful view, and of course, you can now proceed
further to read the great book and learn more.

Happy reading!

Update (2010-2-21): editorial corrections (thank you justin for your suggestions).


MID for Programmers
2008-01-14T12:48:00.001+08:00
Lots of MIDs
were showed off in CES 2008. However, none of them satisfy my
requirements. What I need is a device for web surfing, RSS feed
consuming, programming, and of course blogging. The one closest to my
criterial is from
LG, however I shunned away from Windows. Following is a list of
features I expect an MID to have, from a programmer's perspective.

Mandatory factors:


  Around 5 inch touchscreen. Size matters. The screen
  size is the most difficult factor when making tradeoffs. We want it
  smaller for portability (otherwise why not a gorgeous 17 inch
  MacBook Pro?), but not so small to hurt our eyes. 5 inch seems to
  strike a nice balance. At this size, 800x600 resolution seems to be
  preferred.
  Full keyboard (similar as that of laptop in terms of
  keys equipped). Interface is critical. I am an Emacs fan, and the
  main usage of the MID is to try interesting programming ideas within
  Emacs and to compose blogs as well. Therefore I need the keyboard to
  have Ctrl and Alt equipped as a minimum. I also hope numerical keys
  have their independent positions (e.g. not shared with QWERTYUIOP as
  my Dopod 838, which is really painful). Keyboard from LG prototype
  satisfies all requirements here, therefore I do hope other vendors
  could follow suit.
  Fast CPU. Gentoo
  is my favorite Linux distribution, therefore I may try to
  install it (somebody has already done so
  on Q1 Ultra). In addition to satisfy a power-demanding
  distribution, a powerful CPU is also a right
  for programmer even on such a tiny gadget.
  Linux based OS. Linux will shine on MID, which is
  actually an old news. However, there are also devices
  running Windows at least for Menlow based MIDs, e.g. the one from
  LG. The reason for me to mandate Linux here is that I can easily
  install other flavors of Linux distributions if the device itself
  comes with one. With built-in Linux, we can make sure that source
  code for hardware is readily accessible: every vendor should learn
  something from the event of Eee PC GPL
  issues.
  WiFi access. Connection is important. Without WiFi
  access, I guess we can remove Internet from the name of
  MID.
  Miscellaneous. We should match the fast CPU with at
  least 512 MB RAM. 8 GB internal storage is a minimum to fool
  around. SD card slot is a must to connect the MID with other
  devices, and Bluetooth with A2DP support is necessary to avoid hairy
  wires.


Optional features:


  Phone capability. This feature is actually desperately
  needed. However I doubt whether I could find one MID if I insist on
  this feature. There are various reasons for vendors to drop this
  feature: maturity of the needed software, regulation aspects, and
  marketing issues (imagine the impact on N95 if N810 is a phone)
  etc.
  GPS. This is always a nice feature to enjoy.
  Nice camera. Just imagine the wow moment when you use
  your 5-inch-LCD-digital-camera.


Finally, is it possible for MID + Android?

Features	HV30	HF10	Comments
Price	MSRP price is $999 in US and ¥10580.00 (about $1514) in China	MSRP price is $1099 in US and ¥14080.00 (about $2014) in China	The price difference in China is quite significant, which is true even for street price.
Performance	1/2.7 in. sensor	1/3.2 in. sensor	According to the review, HV30 has slightly better performance over HF10 thanks to larger sensor, however the gain seems to be marginal for most cases.
Functionalities	Viewfinder, Zebra, Peaking
Accessories	Standard accessory shoe	Canon proprietary accessory shoe
Backup	Tapes are cheap for backup	Additional backup is needed since SDHC cards are expensive and will be reused.
Community	A mature community (looking at hv20.com for example)	Situation will improve
Form Factor	88x82x138 mm (3.5x3.2x5.4 in.), 535 g (1.2 lb.)	73x64x129 mm (2.9x2.5x5.1 in.), 380 g (13.4 oz)	HF10 is small and light, which is ideal for traveling. Normally the camcorder which you takes out often is the most useful one.
Media	Tape	SDHC card + internal Flash	Flash card is really convenient: just like small DCs. No hassles for rewinding and no worry for overriding.
Zoom	10x optical zoom	12x optical zoom
Noise	Tape noise can be heard in silent environment	No such noise since flash card is used.