Reading....

http://joshua14.homelinux.org/blog/?p=660

Apt-Target release,how to set?

if you want to spin unstable tool, you should do.. 

• edit /etc/apt/conf.d/sources.list

 

                #### add line unstable #########
deb http://ftp.us.debian.org/debian unstable main contrib non-free

• apt-get update 

Retrieve new lists of packages 
 

reference:

1. https://wiki.debian.org/AptPreferences

Sound Card

 About Debian [1]

reference:

1. https://wiki.debian.org/SoundCard

Print Detailed information about all PCI buses and devices in the system

lspci

• a command on Unix-like operating systems that prints detailed information about all PCI buses and devices in the system.

-v (for detail)
-nn (Show both textual and numeric ID's (names & numbers))

reference:

1. http://en.wikipedia.org/wiki/Lspci 
2. https://wiki.debian.org/HowToIdentifyADevice/PCI

Commands refered to Sound

aplay

• play audio
• ex: aplay -l

arecord

• record audio

Linux Sound Architecture

Advanced Linux Sound Architecture (ALSA)

Part of Linux Kernel  is a software framework that supported API for sound card device driver.

Example of rerouted sound

•   application->pulseaudio->ALSA->hardware

alsamixer:

A graphical mixer program for ALSA that used to adjust
adjust the volume and configuration.

reference:

1. http://www.alsa-project.org/main/index.php/Main_Page
2. http://en.wikipedia.org/wiki/PulseAudio
3. http://en.wikipedia.org/wiki/Advanced_Linux_Sound_Architecture

PulseAudio

In brief, PulseAudio is a proxy for your sound applications.
In Debian, applications such as Flesh, Skype are based on  PulseAudio.
(Just know the name, but not study in depth.)


reference:

1. https://wiki.debian.org/en/PulseAudio#Various_problems_with_Skype_and_Wine
2. http://www.freedesktop.org/wiki/Software/PulseAudio/

Init script

Debian uses a Sys-V like init system for executing shell scripts when the system runlevel changes. How to do?

• /etc/init.d/xxx (xxx : your init script)
• update-rc xxx

 
Adding symbolic links to cause the script to be executed when the system goes down, or comes up.

The example of script executed as init.

• The script is just a  shell script with  'Switch case ' statement.

..................................................................................................................

#! /bin/sh
# /etc/init.d/blah
#

# Some things that run always
touch /var/lock/blah

# Carry out specific functions when asked to by the system
case "$1" in
  start)
    echo "Starting script blah "
    echo "Could do more here"
    ;;
  stop)
    echo "Stopping script blah"
    echo "Could do more here"
    ;; 

  restart|reload)

    $0 stop
    sleep 3
    $0 start

  ;;

  *)

    echo "Usage: /etc/init.d/blah {start|stop}"
    exit 1
    ;;
esac

exit 0

................................................................................... 

reference:

1. http://www.debian-administration.org/articles/28