Live Note

Remain optimistic

工厂模式

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
let Basketball = function () {
this.name = 'basketball'
}
Basketball.prototype = {
getMember: function () {
console.log(5)
},
getBallSize: function () {
console.log('big')
},
}

let FootBall = function () {
this.name = 'football'
}
FootBall.prototype = {
getMember: function () {
console.log(11)
},
getBallSize: function () {
console.log('big')
},
}

let Tennis = function () {
this.name = 'tennis'
}
Tennis.prototype = {
getMember: function () {
console.log(1)
},
getBallSize: function () {
console.log('small')
},
}

let SportFactory = function (name) {
switch (name) {
case 'basketball':
return new Basketball()
case 'football':
return new FootBall()
case 'tennis':
return new Tennis()
}
}

let footBall = new SportFactory('football')
footBall.getMember()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
// Product base attribute
interface Product {
operation(): string
}

class ConcreteProduct1 implements Product {
public operation(): string {
return 'This is Product1'
}
}
class ConcreteProduct2 implements Product {
public operation(): string {
return 'This is Product2'
}
}

abstract class Creator {
public abstract factoryMethod(): Product

public operation(): string {
const product = this.factoryMethod()

return product.operation()
}
}

class ConcreteCreator1 extends Creator {
public factoryMethod(): Product {
return new ConcreteProduct1()
}
}
class ConcreteCreator2 extends Creator {
public factoryMethod(): Product {
return new ConcreteProduct2()
}
}

// usage
function clientCode(creator: Creator) {
console.log(creator.operation())
}

clientCode(new ConcreteCreator1())
clientCode(new ConcreteCreator2())

安全工厂

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
let Factory = function (type, content) {
if (this instanceof Factory) {
// check if is instance Factory
return new this[type](content)
} else {
return new Factory(type, content)
}
}
Factory.prototype = {
Java: function (content) {
console.log(content)
},
JavaScript: function (content) {
console.log(content)
},
}

let data = [
{
type: 'Java',
content: 'This is Java',
},
{
type: 'JavaScript',
content: 'This is JavaScript',
},
]

// for test
for (let i = 0; i < data.length; i++) Factory(data[i].type, data[i].content)

抽象工厂

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
/**
* to extend superType
* @param {*} subType
* @param {*} superType
*/
let VehicleFactory = (subType, superType) => {
if (typeof VehicleFactory[superType] === 'function') {
function F() {}
F.prototype = new VehicleFactory[superType]()
subType.constuctor = subType
subType.prototype = new F()
} else {
throw new Error("don' not have this abstract class")
}
}

// create base class
VehicleFactory.Car = function () {
this.type = 'car'
}
VehicleFactory.Car.prototype = {
getPrice: function () {
return new Error('abstract')
},
getSpeed: function () {
return new Error('abstract')
},
}

let BMW = function (price, speed) {
this.price = price
this.speed = speed
}
VehicleFactory(BMW, 'Car') // interface
BMW.prototype = {
getPrice: function () {
return this.price
},
getSpeed: function () {
return this.speed
},
}

// for test
let myBmw = new BMW(10000, 100)
console.log(myBmw.getPrice())
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
// product interface
interface AbstractProductA {
functionA(): string
}

interface AbstractProductB {
/**
* base operation
* @return {string}
*/
functionA(): string

/**
* inject some operation
* @param {AbstractProductA} product
* @return {string}
*/
functionB(product: AbstractProductA): string
}

// concrete production
class ConcreteProductA1 implements AbstractProductA {
functionA(): string {
return 'This is functionA from ProductA1'
}
}
class ConcreteProductA2 implements AbstractProductA {
functionA(): string {
return 'This is functionA from ProductA2'
}
}
class ConcreteProductB1 implements AbstractProductB {
functionA(): string {
return 'This is functionA from ProductB1'
}

functionB(product: AbstractProductA): string {
return 'Function B2: ' + product.functionA()
}
}
class ConcreteProductB2 implements AbstractProductB {
functionA(): string {
return 'This is functionA from ProductB2'
}

functionB(product: AbstractProductA): string {
return 'Function B2: ' + product.functionA()
}
}

// factory interface
interface AbstractFactory {
createProductA(): AbstractProductA
createProductB(): AbstractProductB
}

// concrete factory
class ConcreteFactory1 implements AbstractFactory {
createProductA(): AbstractProductA {
return new ConcreteProductA1()
}

createProductB(): AbstractProductB {
return new ConcreteProductB1()
}
}
class ConcreteFactory2 implements AbstractFactory {
createProductA(): AbstractProductA {
return new ConcreteProductA2()
}

createProductB(): AbstractProductB {
return new ConcreteProductB2()
}
}

// usage
/**
* use with different facotry.
* @param {AbstractFactory} factory
*/
function clientCode(factory: AbstractFactory) {
const productA = factory.createProductA()
const productB = factory.createProductB()

console.log(productB.functionA())
console.log(productB.functionB(productA))
}

clientCode(new ConcreteFactory1())
clientCode(new ConcreteFactory2())

子类的原型对象-类式继承

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
// 类式继承
// parent
function SuperClass() {
this.superValue = true
}
SuperClass.prototype.getSuperValue = function () {
return this.superValue
}

// child
function SubClass() {
this.subValue = false
}
SubClass.prototype = new SuperClass()
SubClass.prototype.getSubValue = function () {
return this.subValue
}

let child = new SubClass()
console.log(child.getSuperValue()) // true
console.log(child.getSubValue()) // false
Read more »

1
Set-cookie: value[; expires=date][; domain=domain][; path=path][; secure]

每个选项都是用分号和空格来分开,每个选项都制定了 cookie 在什么情况下会发送给服务器

过期时间选项

  • expires: 指定了 cookie 最长存储时间,过期后会被浏览器删除。值是一个 date ,格式为 WDY, DD-mm-YYYY HH:MM:SS GMT
  • 没有设置 expires 选项时,默认为当前会话,所设置的 cookie 在关闭浏览器时会被删除。
1
Set-cookie: name=Jack; expires=Tue, 28 May 2019 22:33:22 GMT

domain 选项

  • domain: 指定了 cookie 将要被发给哪个域中。
  • 默认情况下会被设置为当前域。
  • 值必须是消息头主机的一部分,不合法的 domain 会直接被忽略。
1
Set-cookie: name=Jack; domain=baidu.com

path 选项

  • path: 指定了请求资源的 URL 中存在指定路径时,才会发送 cookie。
  • 只有对 domain 匹配成功后才会开始匹配 path 部分。
1
Set-cookie: name=Jack; domain=baidu.com; path=/

secure 选项

  • secure: 只是一个标记,当请求通过 SSL 或者 HTTPS 创建时,包含 secure 的 cookie 才会被发送至服务器。
  • 默认情况下, HTTPS 上传输的 cookie 都会被自动加上 secure 选项。
1
Set-cookie: name=Jack; secure

HTTPOnly 选项

  • HttpOnly: 禁止浏览器通过 JavaScript 来获取 cookie ,防止 XSS 攻击。
  • 这个属性也不能通过 JavaScript 来设置。
1
Set-cookie: name=Jack; HttpOnly
  1. 会话结束。
  2. 超过过期时间。
  3. cookie 数量达到限制,删除部分 cookie 以便为新创建的 cookie 腾出空间。

可以使用document.cookie来读取 cookie 的值。

要求

  1. 程序 1 从串口读取信息,然后发到消息队列中。使用 2 个终端运行程序 1,创建出 2 个可从串口读取数据的进程,串口可以使用 Windows 中的虚拟串口,使用串口助手输入信息。
  2. 程序 2 从消息队列中读取消息,然后在屏幕上将消息内容显示出来。

提交形式

  1. 代码
  2. 运行结果截图、串口助手截图
Read more »

TV series

  • Game of Thrones
  • WestWorld
  • Chernobyl
  • Fantasmagorias
  • Love, Death & Robots
Read more »

有名管道

  1. 父进程创建一个有名管道,然后创建 1 个子进程,父进程阻塞的方式等待有名管道的信息,当读取到信息之后,在屏幕上打印出来;当从有名管道中读取到“QUIT”之后,父进程终止。
  2. 子进程 1 使用定时器,每 5 秒钟向有名管道输入“this is process 1”;当收到信号 SIGQUIT 时,向有名管道输出“QUIT”,并在屏幕上输出“process 1 exit”之后,进程终止。

提交形式

  1. 代码
  2. 运行结果截图
Read more »

要求

父进程创建 3 个进程,父进程等待子进程 2 运行完成之后,自行退出;其中子进程 1 运行系统命令“cp /bin/ls /tmp”;等待 2 秒后退出;子进程 2 使用标准 I/O 函数打开文件 src_file,向其内写入“this is process 2\n”,之后等待 5 秒后退出;子进程 3 处理为守护进程,每隔 5 秒向日志文件/var/log/messages 写入“this is process 3\n”

提交形式

  1. 代码
  2. 运行结果截图
Read more »

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
/**
* set the cookie
* @param {String} name
* @param {String} value
* @param {Number} day
*/
let setCookie = (name, value, day) => {
let date = new Date()
date.setDate(date.getDate() + day)
document.cookie = name + "=" + value + ";expires=" + date
}

/**
* get the cookie by name
* @param {String} name
*/
let getCookie = (name) => {
let str = document.cookie.split("; ").filter((i) => {
let result = i.split("=")
return result[0] == name
})
return str.length ? str[0].split("=")[1] : ""
}

/**
* check user
*/
let checkCookie = () => {
let username = document.cookie ? getCookie("username") : ""
if (username != "") {
alert("Welcome " + username)
} else {
username = prompt("please input your username")
if (username && username != "") {
setCookie("username", username, 7)
}
}
}

checkCookie()
console.log(getCookie("username"))

Linux 常用命令

  • man: an interface to the on-line reference manuals
  • su [options] [username]: change user ID or become superuser
  • useradd [options] LOGIN: create a new user or update default new user information
  • userdel [options] LOGIN: delete a user account and related files
  • passwd [options] [LOGIN]: change user password
  • ps [options]: report a snapshot of the current process.
  • kill [options] […]: send a signal to a process
  • fdisk [options] device: manipulate disk partition table
  • mount: mount a filesystem
  • chown [OPTION] … [OWNER]:[GROUP]] FILE …: change file owner and group
  • chgrp [OPTION] … GROUP FILE …: change group ownership
  • chmod [OPTION] … MODE[,MODE] … FILE …: change file mode bits
  • grep [OPTION] PATTERN [FILE…]: print lines matching a pattern
  • find [-H] [-L] [-P] [-D debugopts] [-Olevel] [starting-point…] [expression]: search for files in a directory hierarchy
  • ln: make links between files
  • gzip, gunzip, zcat: compress or expand files
  • tar: an archiving utility
  • diff [OPTION] … FILES: compare files line by line
  • patch -pnum < patchfile: apply a diff file to an original
  • ifconfig: configure a network interface

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
import System.Environment
import System.Directory
import System.IO
import Data.List

main = do
(command:args) <- getArgs -- get the command
let (Just action) = lookup command dispatch -- find the command
action args -- do something

add :: [String] -> IO ()
add [fileName, todoItem] = appendFile fileName (todoItem ++ "\n") -- add the todoItem

view :: [String] -> IO ()
view [fileName] = do -- match the filename
contents <- readFile fileName -- read the file
let todoTasks = lines contents -- get the contents
numberedTasks = zipWith (\n line -> show n ++ ": " ++ line) [0..] todoTasks
putStrLn $ unlines numberedTasks -- show the items

remove :: [String] -> IO ()
remove [fileName, numberString] = do -- get the filename and the line number
handle <- openFile fileName ReadMode
(tempName, tempHandle) <- openTempFile "." "temp" -- create a temp file
contents <- hGetContents handle -- get contents from the handle
let number = read numberString -- read the String to Number
todoTasks = lines contents
newTodoTasks = delete (todoTasks !! number) todoTasks -- remove the line of the number
hPutStr tempHandle $ unlines newTodoTasks -- putStr into the tempfile
hClose handle -- close handles
hClose tempHandle
removeFile fileName
renameFile tempName fileName

dispatch :: [(String, [String] -> IO ())]
dispatch = [
("add", add),
("view", view),
("remove", remove)
]

-- runhaskell arags-test.hs view newData.txt
-- runhaskell args-test.hs add newData.txt "Say Hello"
-- runhaskell args-test.hs remove newData.txt 4