Go语言上手--基础语言 | 青训营笔记

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这是我参与「第三届青训营 -后端场」笔记创作活动的的第1篇笔记。

环境搭建

这是我第一次接触GO语言,在原来C++的开发环境基础上增加了GO语言的支持。

操作系统:Archlinux

代码编辑器:neovim

安装GOyay -S go

代码补全:LSP增加语言服务器gopls

至此即可用go run运行go文件。

课堂收获

语言基础

GO语言语法上感觉类似C++,但是比C++更简洁。

  1. import用来导入标准库,以使用标准库支持的函数,这个导入会比较严谨,没有使用到的必须从import中删除,否则会导致报错。

  2. 声明变量,可以用var 变量名 变量类型var 变量名 = 初值变量名 := 初值等方式。

  3. iffor循环不需要小括号,需要大括号,可以利用range来进行循环遍历的工作。

  4. 切片,相当于一个可变长度的数组,利用make来创建,append追加元素。

  5. map,利用make(map[key]value)创建,利用map[key]来访问value。

  6. 指针,与C++类似,用&取地址,*取地址中的值,但是不存在指针运算。

  7. 结构体方法定义在结构体外,从一个普通函数改为结构体方法,可以把第一个参数加上括号写到函数名前。

简单记录一下这些点,方便后续使用GO语言编程时查看。

项目实战

生成随机数

这个比较简单,利用即时的时间初始化随机数种子,生成一个100以内的随机数,不断与用户输入的数进行比较,并提示答案与输入的数比较大小的结果,直到猜中随机数。

在线词典

利用翻译软件公开的API,向服务器发送申请,收到的消息按照特定翻译软件的格式解析接收,读取需要的部分内容。

  1. 抓包:在翻译的网页右键->检查->Network,随便输入一个单词翻译,在出现的一系列请求中找到用来查单词的请求。

  2. 生成代码:查单词的请求上右键->copy->copy as cURL,将复制的内容粘贴到https://curlconverter.com/#go,用curl命令生成对应的Go语言代码。

  3. 直接运行这一段粘贴的代码,打印bodyText,将打印的内容复制粘贴到https://oktools.net/json2go,生成response结构体,将打印bodyText部分的代码改为用json.Unmarshal将bodyText的内容解析存入response结构体。

  4. 把发送请求中的单词用变量替换掉,变量作为程序输入的参数,最后打印response结构体中所需的部分。

SOCKS5代理

这个项目的关键是实现auth认证和connect连接两个部分,通过持续监听本地特定端口,使得需要经过代理的网络数据全部通过特定端口转发。

课后作业

  1. 修改第一个例子猜谜游戏里面的最终代码,使用fmt.Scanf来简化代码实现

注释掉reader和strings处理相关的函数,因为reader部分读取字符串,再用strings通过字符串转数字得到输入,如果改为fmt.Scanf,可以直接获取输入。

package main

import (
	"fmt"
	"math/rand"
	"time"
)

func main() {
	maxNum := 100
	rand.Seed(time.Now().UnixNano())
	secretNumber := rand.Intn(maxNum)
	// fmt.Println("The secret number is ", secretNumber)

	fmt.Println("Please input your guess")
	// reader := bufio.NewReader(os.Stdin)
	for {
		// input, err := reader.ReadString('\n')
                var guess int
                _, err := fmt.Scanf("%d\n", &guess)
		if err != nil {
			fmt.Println("An error occured while reading input. Please try again", err)
			continue
		}
		/* input = strings.TrimSuffix(input, "\n")

		guess, err := strconv.Atoi(input)
		if err != nil {
			fmt.Println("Invalid input. Please enter an integer value")
			continue
		} */
		fmt.Println("You guess is", guess)
		if guess > secretNumber {
			fmt.Println("Your guess is bigger than the secret number. Please try again")
		} else if guess < secretNumber {
			fmt.Println("Your guess is smaller than the secret number. Please try again")
		} else {
			fmt.Println("Correct, you Legend!")
			break
		}
	}
}
  1. 修改第二个例子命令行词典里面的最终代码,增加另一种翻译引擎的支持

增加了Deepl翻译的支持,方法和增加原来的翻译引擎一样,只需要在main函数中改为调用新的函数即可。

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"os"
        "strings"
)

type DeeplResponse struct {
	Jsonrpc string `json:"jsonrpc"`
	ID int `json:"id"`
	Result struct {
		Translations []struct {
			Beams []struct {
				Sentences []struct {
					Text string `json:"text"`
					Ids []int `json:"ids"`
				} `json:"sentences"`
				NumSymbols int `json:"num_symbols"`
			} `json:"beams"`
			Quality string `json:"quality"`
		} `json:"translations"`
		TargetLang string `json:"target_lang"`
		SourceLang string `json:"source_lang"`
		SourceLangIsConfident bool `json:"source_lang_is_confident"`
		DetectedLanguages struct {
		} `json:"detectedLanguages"`
	} `json:"result"`
}

func deeplQuery(word string) {
    client := &http.Client{}
	var data = strings.NewReader(fmt.Sprintf(`{"jsonrpc":"2.0","method": "LMT_handle_jobs","params":{"jobs":[{"kind":"default","sentences":[{"text":"%s","id":0,"prefix":""}],"raw_en_context_before":[],"raw_en_context_after":[],"preferred_num_beams":4}],"lang":{"preference":{"weight":{},"default":"default"},"source_lang_computed":"EN","target_lang":"ZH"},"priority":1,"commonJobParams":{"browserType":1,"formality":null},"timestamp":1651926295556},"id":16030005}`, word))
	req, err := http.NewRequest("POST", "https://www2.deepl.com/jsonrpc?method=LMT_handle_jobs", data)
	if err != nil {
		log.Fatal(err)
	}
	req.Header.Set("authority", "www2.deepl.com")
	req.Header.Set("accept", "*/*")
	req.Header.Set("accept-language", "zh-CN,zh;q=0.9")
	req.Header.Set("content-type", "application/json")
	req.Header.Set("cookie", "LMTBID=v2|c013597b-84fb-4a39-b23a-eb997a9f8a37|3f6f5cc11afeef851467f5aa326e4f10; dapUid=d9103499-72db-48c2-a216-0eb86d4aeb92; privacySettings=%7B%22v%22%3A%221%22%2C%22t%22%3A1651881600%2C%22m%22%3A%22LAX_AUTO%22%2C%22consent%22%3A%5B%22NECESSARY%22%2C%22PERFORMANCE%22%2C%22COMFORT%22%5D%7D; dapVn=2; dapSid=%7B%22sid%22%3A%2261194e02-f312-4648-be2f-23b4dd50ca16%22%2C%22lastUpdate%22%3A1651926295%7D")
	req.Header.Set("origin", "https://www.deepl.com")
	req.Header.Set("referer", "https://www.deepl.com/")
	req.Header.Set("sec-ch-ua", `" Not A;Brand";v="99", "Chromium";v="101", "Google Chrome";v="101"`)
	req.Header.Set("sec-ch-ua-mobile", "?0")
	req.Header.Set("sec-ch-ua-platform", `"Linux"`)
	req.Header.Set("sec-fetch-dest", "empty")
	req.Header.Set("sec-fetch-mode", "cors")
	req.Header.Set("sec-fetch-site", "same-site")
	req.Header.Set("user-agent", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.41 Safari/537.36")
	resp, err := client.Do(req)
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()
	bodyText, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Fatal(err)
	}
	// fmt.Printf("%s\n", bodyText)
        var deeplResponse DeeplResponse
            err = json.Unmarshal(bodyText, &deeplResponse)
            if err != nil {
                    log.Fatal(err)
            }
        fmt.Println(word, ":")
        for _, item1 := range deeplResponse.Result.Translations {
            for _, item2 := range item1.Beams {
                for _, item3 := range item2.Sentences {
                    fmt.Println(item3.Text)
                }
            }
        }
}

func main() {
	if len(os.Args) != 2 {
		fmt.Fprintf(os.Stderr, `usage: simpleDict WORD
example: simpleDict hello
		`)
		os.Exit(1)
	}
	word := os.Args[1]
	deeplQuery(word)
}
  1. 在上一部的基础上,修改代码实现并行请求两个翻译引擎来提高响应速度

只需要修改第2题的main函数,声名一个WaitGroup变量,调用Add函数等待一个结果,同时调用两个翻译功能函数,任何一个返回结果后都会退出等待。

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"strings"
	"sync"
)

type DictRequest struct {
	TransType string `json:"trans_type"`
	Source    string `json:"source"`
	UserID    string `json:"user_id"`
}

type DictResponse struct {
	Rc   int `json:"rc"`
	Wiki struct {
		KnownInLaguages int `json:"known_in_laguages"`
		Description     struct {
			Source string      `json:"source"`
			Target interface{} `json:"target"`
		} `json:"description"`
		ID   string `json:"id"`
		Item struct {
			Source string `json:"source"`
			Target string `json:"target"`
		} `json:"item"`
		ImageURL  string `json:"image_url"`
		IsSubject string `json:"is_subject"`
		Sitelink  string `json:"sitelink"`
	} `json:"wiki"`
	Dictionary struct {
		Prons struct {
			EnUs string `json:"en-us"`
			En   string `json:"en"`
		} `json:"prons"`
		Explanations []string      `json:"explanations"`
		Synonym      []string      `json:"synonym"`
		Antonym      []string      `json:"antonym"`
		WqxExample   [][]string    `json:"wqx_example"`
		Entry        string        `json:"entry"`
		Type         string        `json:"type"`
		Related      []interface{} `json:"related"`
		Source       string        `json:"source"`
	} `json:"dictionary"`
}

type DeeplResponse struct {
	Jsonrpc string `json:"jsonrpc"`
	ID int `json:"id"`
	Result struct {
		Translations []struct {
			Beams []struct {
				Sentences []struct {
					Text string `json:"text"`
					Ids []int `json:"ids"`
				} `json:"sentences"`
				NumSymbols int `json:"num_symbols"`
			} `json:"beams"`
			Quality string `json:"quality"`
		} `json:"translations"`
		TargetLang string `json:"target_lang"`
		SourceLang string `json:"source_lang"`
		SourceLangIsConfident bool `json:"source_lang_is_confident"`
		DetectedLanguages struct {
		} `json:"detectedLanguages"`
	} `json:"result"`
}

func deeplQuery(word string) {
        client := &http.Client{}
	var data = strings.NewReader(fmt.Sprintf(`{"jsonrpc":"2.0","method": "LMT_handle_jobs","params":{"jobs":[{"kind":"default","sentences":[{"text":"%s","id":0,"prefix":""}],"raw_en_context_before":[],"raw_en_context_after":[],"preferred_num_beams":4}],"lang":{"preference":{"weight":{},"default":"default"},"source_lang_computed":"EN","target_lang":"ZH"},"priority":1,"commonJobParams":{"browserType":1,"formality":null},"timestamp":1651926295556},"id":16030005}`, word))
	req, err := http.NewRequest("POST", "https://www2.deepl.com/jsonrpc?method=LMT_handle_jobs", data)
	if err != nil {
		log.Fatal(err)
	}
	req.Header.Set("authority", "www2.deepl.com")
	req.Header.Set("accept", "*/*")
	req.Header.Set("accept-language", "zh-CN,zh;q=0.9")
	req.Header.Set("content-type", "application/json")
	req.Header.Set("cookie", "LMTBID=v2|c013597b-84fb-4a39-b23a-eb997a9f8a37|3f6f5cc11afeef851467f5aa326e4f10; dapUid=d9103499-72db-48c2-a216-0eb86d4aeb92; privacySettings=%7B%22v%22%3A%221%22%2C%22t%22%3A1651881600%2C%22m%22%3A%22LAX_AUTO%22%2C%22consent%22%3A%5B%22NECESSARY%22%2C%22PERFORMANCE%22%2C%22COMFORT%22%5D%7D; dapVn=2; dapSid=%7B%22sid%22%3A%2261194e02-f312-4648-be2f-23b4dd50ca16%22%2C%22lastUpdate%22%3A1651926295%7D")
	req.Header.Set("origin", "https://www.deepl.com")
	req.Header.Set("referer", "https://www.deepl.com/")
	req.Header.Set("sec-ch-ua", `" Not A;Brand";v="99", "Chromium";v="101", "Google Chrome";v="101"`)
	req.Header.Set("sec-ch-ua-mobile", "?0")
	req.Header.Set("sec-ch-ua-platform", `"Linux"`)
	req.Header.Set("sec-fetch-dest", "empty")
	req.Header.Set("sec-fetch-mode", "cors")
	req.Header.Set("sec-fetch-site", "same-site")
	req.Header.Set("user-agent", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.41 Safari/537.36")
	resp, err := client.Do(req)
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()
	bodyText, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Fatal(err)
	}
	// fmt.Printf("%s\n", bodyText)
        var deeplResponse DeeplResponse
            err = json.Unmarshal(bodyText, &deeplResponse)
            if err != nil {
                    log.Fatal(err)
            }
        fmt.Println(word, ":")
        for _, item1 := range deeplResponse.Result.Translations {
            for _, item2 := range item1.Beams {
                for _, item3 := range item2.Sentences {
                    fmt.Println(item3.Text)
                }
            }
        }
}

func query(word string) {
	client := &http.Client{}
	request := DictRequest{TransType: "en2zh", Source: word}
	buf, err := json.Marshal(request)
	if err != nil {
		log.Fatal(err)
	}
	var data = bytes.NewReader(buf)
	req, err := http.NewRequest("POST", "https://api.interpreter.caiyunai.com/v1/dict", data)
	if err != nil {
		log.Fatal(err)
	}
	req.Header.Set("Connection", "keep-alive")
	req.Header.Set("DNT", "1")
	req.Header.Set("os-version", "")
	req.Header.Set("sec-ch-ua-mobile", "?0")
	req.Header.Set("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.51 Safari/537.36")
	req.Header.Set("app-name", "xy")
	req.Header.Set("Content-Type", "application/json;charset=UTF-8")
	req.Header.Set("Accept", "application/json, text/plain, */*")
	req.Header.Set("device-id", "")
	req.Header.Set("os-type", "web")
	req.Header.Set("X-Authorization", "token:qgemv4jr1y38jyq6vhvi")
	req.Header.Set("Origin", "https://fanyi.caiyunapp.com")
	req.Header.Set("Sec-Fetch-Site", "cross-site")
	req.Header.Set("Sec-Fetch-Mode", "cors")
	req.Header.Set("Sec-Fetch-Dest", "empty")
	req.Header.Set("Referer", "https://fanyi.caiyunapp.com/")
	req.Header.Set("Accept-Language", "zh-CN,zh;q=0.9")
	req.Header.Set("Cookie", "_ym_uid=16456948721020430059; _ym_d=1645694872")
	resp, err := client.Do(req)
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()
	bodyText, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Fatal(err)
	}
	if resp.StatusCode != 200 {
		log.Fatal("bad StatusCode:", resp.StatusCode, "body", string(bodyText))
	}
	var dictResponse DictResponse
	err = json.Unmarshal(bodyText, &dictResponse)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(word, "UK:", dictResponse.Dictionary.Prons.En, "US:", dictResponse.Dictionary.Prons.EnUs)
	for _, item := range dictResponse.Dictionary.Explanations {
		fmt.Println(item)
	}
}

func main() {
	if len(os.Args) != 2 {
		fmt.Fprintf(os.Stderr, `usage: simpleDict WORD
example: simpleDict hello
		`)
		os.Exit(1)
	}
        var wg sync.WaitGroup
        wg.Add(1)
        go func() {
            defer wg.Done()
            deeplQuery(os.Args[1])
        }()
        go func() {
            defer wg.Done()
            query(os.Args[1])
        }()
        wg.Wait()
}