Programmer's Notebook

Using Emacs as presentation tool Using Emacs as Presentation tool Emacs is not just a editor, I found some hackers even use it to do presentations. So I collected some ways that emacs can become an presentation tool. Table of Contents 1 This article is not about… 2 epresent.el 3 Sacha Chua's source code. 4 Improved epresent.el 1 This article is not about… First, I must make a clearly announcement about what this article is not about. This article is not about how to make a pdf file style presentation using emacs as a editor, and using anther tools like a pdf viewer to play this slides. This article is about how to using emacs as an presentation style slides player. 2 epresent.el Epresent is an simple presentation mode for org-mode. How to use it? load eprsent.el into emacs open a org file (present.org). M-x epresent-run press "t" to view the top level of presentation navigate the presentation with 'n', ...

Pulseaudio-mode for emacs Pulseaudio-mode for emacs Table of Contents 1 Get Source code 2 How to install it? 3 How to use it? 1 Get Source code You can download source code from my github repository . or you can clone the repository directly by git. git clone https://github.com/suzp1984/pulseaudio-mode.git 2 How to install it? First, get the source code according to above section. Add following line into your emacs's init file ;; replace following parameter into actual directory path. (add-to-list 'load-path "directory path to pulseaudio-autoload.el" ) ( require ' pulseaudio-autoload ) 3 How to use it? Start pulseaudio modules management by M-x list-pulseaudio-modules Start pulseaudio sinks management by M-x list-pulseaudio-sinks … x. Maybe add more function to make it more like a powerful pulseaudio control panel.

One way to record a program's Audio output Table of Contents 1 PulseAudio Audio Server Introduction 2 Record a program's Audio output. 1 PulseAudio Audio Server Introduction Linux Audio System can be divided into 3 layers. Alsa/Oss package provide a bottom layer to driver sound card. PulseAudio/Jack/ESD package provide middle ware layer named Audio Server. Multimedia applications written by the API provided by Audio Server. PulseAudio is focused on desktop and mobile audio needs. It doesn't try to address low latency, but does provide seamless device switching, network routing, global per-application volume control and lots great stuff. 2 Record a program's Audio output. Following is the step by step tutorial to record an Audio output. Load a null-sink pactl load-module module-null-sink sink_name =steam Load combine-sink module-combine-sink is used to combine slaves sinks to build virtual sinks. # First use "pactl list ...

Suspend my laptop by Command Suspend my laptop by Command I upgrade my fedora desktop to fedora18, and get some trouble after upgrade. One of them is that my old script to suspend my laptop do not works anymore(I like to suspend my laptop without close its screen lid.) . My old script to suspend the PC: # !/bin/ bash dbus-send --system --print-reply --dest=org.freedesktop.Hal \ /org/freedesktop/Hal/devices/computer \ org.freedesktop.Hal.Device.SystemPowerManagement.Suspend \ int32:0 Table of Contents 1 Why HAL dbus interface did not works 2 Two ways to Suspend/Hibernate the Laptop 1 Why HAL dbus interface did not works The reason is that HAL(Hardware Abstraction layer) is now deprecated on freedesktop environment, and it is emerged into udev package. In HAL's offical website, It declared that HAL is in maintenance mode, all future development focus in udisks and upower. So I guess upower maybe provide some power ma...

PGP toolkit in Linux Table of Contents 1 Philip R. Zimmermann 2 What is digital certificate? 3 X509 .VS. PGP 4 PGP tools in Linux platform 4.1 Generate your own self-signed Certificate 4.2 encypt and decrypt by gpg 4.3 Manager your Certificats 5 PGP in Emacs 5.1 Easy PG package in emacs 5.2 encrypt/sign email in gnus 5.3 epa-mail* .VS. mml-secure-message-* 1 Philip R. Zimmermann Zimmermann is the creator of Pretty Good Privacy(PGP) which become the standard of protocol named OpenPGP. In the era before 90s century, US government held a export restrictions for cryptography software(This bullshit policy sounds like censorship in china today right? But the different is that a lot of SOB in china government.). But Zimmermann made PGP as a open source software to counterattack government's violate human right behave(The human being's nature right is to pursual for freedom and equality, especially in Internet). This made him the target of a thre...

TTS mode for emacs TTS mode for emacs There are a scene in The big-bang theory, a America TV drama, Sheldon use his laptop computer to emulate human voice. That's really cool. Actually What Sheldon did is just install a TTS software, TTS short for Text To Speech. Table of Contents 1 TTS engine in linux platform 2 The simple way to use Festival and Espeak 3 Why TTS mode? 4 How to use TTS mode? 1 TTS engine in linux platform I use two kinds of TTS engine in my PC, Festival and Espeak. Festival provide a interactive interface with lisp like syntax. Espeak support more language voice. Of course there are another TTS engines in linux platform, I just have a little experience in above two. 2 The simple way to use Festival and Espeak # festival read text from stdin echo "hello world" | festival --tts # festival read text from file festival --tts filename espeak "hello world" # espeak speak chinese espeak -...

Linux Share Memory Linux Share Memory Table of Contents 1 Introduction 2 tmpfs .vs. shm_open 3 shmget .vs. shm_open 1 Introduction Shared memory is one kinds of mechanism to do effective IPC. There are three kinds of API to share memory among different processes: shmget shm_open tmpfs 2 tmpfs .vs. shm_open df -h This command can list the mounted file systems. In general, there will be a record:   tmpfs 1.9G 748K 1.9G 1% /dev/shm tmpfs is one kinds of file system which store the file data in virtual memory instead of hard disk. It can speed up the program which needs temp storage. Because of its file store in virtual memory, It can be used as a shared memory facility. While according to shm_open's manual, the name parameter of shm_open is actually an object name, not a file path. So I read glibc's source code and find the definition the shm_open, It just concatenate tmpfs path name with the ...