計算機程式Note(台大OCW)
===

* Hardware
* Central Processing Unit(CPU)
> Processing: 處理器

* Arithmetic and Logic Unit (ALU)
> Arithmetic: 算數
> Logic: 邏輯

* Main Memory

* Random Access Memory (RAM)
> 與早期磁帶做區隔，磁帶不能Random Access

* 單位:

* bit (b) : o跟1
* Byte (B) : 8 bit
* K : 2^10^
* M : 2^20^
* G : 2^30^
* T : 2^40^

* bit rate :

* 10^3^ bps = 1 Kbps
* 10^6^ bps = 1 Mbps
* 10^9^ bps = 1 Gbps

* Volatile

* Secondary Storage Unit
> E.X. 硬碟、USB...

* Input Unit
> E.X. 滑鼠、鍵盤...

* Network Interface

* Software

* System Software
> E.X. Opearting System

* Application Software
> E.X. PPT, Word

* Programming Language

* Machine Language

* Assembly Language

* High-Level Language

* Six Phares :


* A skeleton Outline of a Simple C++ Program

// ->註解
#include <iostream>
int main (){ // main -> Function name
             
   return 0; // Statement -> ;結尾
   
} 
// {} -> Program goes here

* First Program in C++ : Printing a Line of Text

// Fig. 2.1: fig02_01.cpp
// Text-printing program.
#include <iostream> // allows program to output data to the screen
  
// function main begins program execution
int main()
{ 
   std::cout << "Welcome to C++!\n"; // display message
  
   return 0; // indicate that program ended successfully
} // end function main

190226 Linux note
===

* POSIX
* https://www.gnu.org/software/libc/manual/html_node/POSIX.html#POSIX

* OOM : 記憶體用完
* $ man mount
* $ man

* 隨堂測驗Q1
* 沒有答案
* 如何證明沒有答案？
* 群論
* 隨堂測驗Q2
* Timing attack (wiki)
* SDR attack radio

* compcert
* compcert linux kernel
* [形式化驗證](https://hackmd.io/s/H1xxp3pF0)
* [軟體缺失的危害](https://hackmd.io/s/B1eo44C1-)