Monday, November 28, 2011

Pthreads Programming

POSIX Threads (稱為 Pthreads) 制定與 thread 有關的標準於 IEEE POSIX 1003.1c standard。

參考範例
POSIX Threads Programming, https://computing.llnl.gov/tutorials/pthreads/
POSIX Threads Programming Exercise, https://computing.llnl.gov/tutorials/pthreads/exercise.html

Thursday, November 17, 2011

C Programming exec() family

execl, execlp, execle, execv, execvp - execute a file

int execl(const char *path, const char *arg, ...);
int execlp(const char *file, const char *arg, ...);
int execle(const char *path, const char *arg, ..., char * const envp[]);

execl(), execlp(), execle() 函式使用的 const char *arg 可以視為一連串的參數串列(亦即 arg0, arg1, ...,  argn)。第一個參數(即 arg0) 是此函式呼叫使用的程式檔案名稱,此參數串列必須以 NULL pointer 做為結尾,亦即使用 (char *) NULL 做為最後一個參數。

Tuesday, November 15, 2011

Apple iPad 2 Video How-to

AVPlayer HD
AVPlayer HD for iPad: USD $2.99


OPlayer HD

OPlayer HD for iPad: USD $4.99

參考資料
主題:iPad 2 實測番外篇:播1080p 有計!, http://www.eprice.com.hk/nb/talk/997/1741/


OPlayerHD Lite

OPlayerHD Lite for iPad: Free

GPlayer
http://itunes.apple.com/app/gplayer/id438402174?mt=8
GPlayer for iPhone and iPad: USD $2.99


Write a Lab Report

如何撰寫實驗報告, http://chemistry.about.com/od/chemistrylabexperiments/a/labreports.htm

Wednesday, October 5, 2011

Install Adobe Flash Player on Linux

Flash Player 11 for Linux (YUM) 64-bit

$ sudo yum install adobe-release-x86_64.noarch
$ sudo yum install flash-plugin.x86_64

Restart browser.

Monday, October 3, 2011

Portable Document Format (PDF) tools

Ghostscript
interpreter for the PostScript language and for PDF

Links
http://www.ghostscript.com/


GSview
Ghostscript 的圖形化介面。

Links
GSview, http://pages.cs.wisc.edu/~ghost/gsview/index.htm

gv
Ghostscript 的 PostScript interpreter。

於 Linux 系統使用 yum 安裝套件
$ sudo yum install gv

由於套件相依性,將安裝以下兩個套件 (以 64 bit 系統為例)
gv.x86_64 : A X front-end for the Ghostscript PostScript(TM) interpreter
Xaw3d.x86_64 : A version of the MIT Athena widget set for X

安裝完成後,gv 程式位於 /usr/bin/gv

CutePDF Writer
安裝於 Microsoft Windows 的 PDF 轉檔免費軟體,藉由安裝虛擬的印表機(CutePDF Writer) 可將文件輸出為 PDF 文件。

Links
CutePDF Writer, http://www.cutepdf.com/products/cutepdf/Writer.asp

Tuesday, September 27, 2011

Release Cache Memory

Linux 從 kernel 2.6.16 開始,提供透過指令清除 pagecache、inode、dentry。

$ sync; /sbin/sysctl vm.drop_caches=3

或者
$ sync; echo 3 > /proc/sys/vm/drop_caches

查看清除前的記憶體使用情況
$ cat /proc/meminfo
MemTotal: 10270912 kB
MemFree: 33092 kB
Buffers: 152300 kB
Cached: 9784508 kB
SwapCached: 0 kB
Active: 196180 kB
Inactive: 9802104 kB
SwapTotal: 2031608 kB
SwapFree: 2031608 kB


查看清除後的記憶體使用情況
$ cat /proc/meminfo
MemTotal: 10270912 kB
MemFree: 10061932 kB
Buffers: 408 kB
Cached: 28692 kB
SwapCached: 0 kB
Active: 89624 kB
Inactive: 928 kB
SwapTotal: 2031608 kB
SwapFree: 2031608 kB


參考資料
drop_caches, http://www.linuxinsight.com/proc_sys_vm_drop_caches.html
The Linux Kernel Archives - vm sysctl documentation, http://www.kernel.org/doc/Documentation/sysctl/vm.txt