Find my way home

Just feel and smile...

口試完了

被電爆...
接下來還有好多研究要補QQ

Virtual File System (VFS)

File System Category
Disk-based file system
journal file system: provide backup file system, more security
FAT -> NTFS
Network file system
NFS, SMB(CIFS), Samba(Unix-based SMB), AFS...
Special file system
/proc, /dev, devfs...


File System Abstraction Layer
/tmp (in-memory file system - RAM disk)

Unix file system
Filesystem are mounted at a specific mount point in a global hierarchy known as a namespace.
mount point(nfs, \tmp)

Each component of a path is called a directory entry(dentry)

inode - file's metadata
superblock - filesystm metadata

Non-Unix filesystem still work in Linux(FAT, NTFS)
special processing done on the fly

VFS Objects

superblock, inode, dentry, file
[              static              ]


sync_fs() best effort
link() - create a inode
dentry cache (d-cache)
inode cache (i-cache)

fs_struct (Process decriptor's fs field)

Nothing is trivial

研究不是一件容易的事
比起coding 研究需要花費更多的心思
除了要設想每個可能被擊破論點
還要小心翼翼地花費時間闡述出來

只不過如果研究方向就是錯誤的話
研究出來的結果就是不可行
那要怎麼去扭轉這樣的結論

真的是不容易......

[OpenCV] Camera Capture

Programmer can extract webcam image throuhg OpenCV easily. 
Following is the example code.

[code]  
    CvCapture *capture;
    IplImage *frame;
    capture =cvCaptureFromCAM(0) ;           //camera init
    cvNamedWindow("Webcam",0);               //highgui window init
    while(TRUE)
    {
        frame = cvQueryFrame(capture);       //extract from CvCapture struct
        cvShowImage("Webcam",frame);         //show frame
        if(cvWaitKey(10)>=0)              //wait for key in
        {
            break;
        }
    }
    cvReleaseCapture(&capture);
    cvDestroyWindow("Webcam");

pkg-config

pkg-config is a useful tool for compiling.
It helps to insert correct compiler options on the command line for gcc/g++ compiler.
example:

            `pkg-config gtk+-2.0 --cflags`                      //include gtk+2.0 lib
            `pkg-config opencv --libs --cflags opencv`    //include opencv lib

[Reference]
pkg-config wiki - http://pkg-config.freedesktop.org/wiki/

[NSLAB] Fun Time

[Reference]
1. wiki
2. youtube

[本報告僅供學術參考]