Golang common basic knowledge points

document

1. Create a file

os.Create(filename)

2. Open the file

1) read only

os.OpenFile(filename, os.O_RDONLY, os.ModePerm)

2) write

f, err := os.OpenFile(filename, os.O_WRONLY, os.ModePerm)

3) Add

os.OpenFile(filename, os.O_APPEND|os.O_WRONLY, os.ModeAppend)

3. Determine whether the file exists

if _, err := os.Stat(filename); os.IsNotExist(err) {
 f, _ = os.Create(filename)
}

4. Write the file

//Write方法写入
f.Write([]byte(content))
//Writestring方法写入
f.WriteString(content)

ask

1. Get request

resp, err := http.Get(url)
//关闭连接
defer resp.Body.Close()
//读取内容
body, err := ioutil.ReadAll(resp.Body)

2.Post request

resp, err := http.Post(url,"application/x-www-form-urlencoded",strings.NewReader("name=1&pwd=2")
//关闭连接
defer resp.Body.Close()
//读取内容
body, err := ioutil.ReadAll(resp.Body)

time

1. Timestamp

time.Now().Unix()

2. Date conversion

time.Now().Local().Format("2006-01-02 15:04:05.000")

3. Timer

t := time.Tick(1 * time.Second)
go onTime(t)

encryption

Md5 encryption

h := md5.New()
h.Write([]byte(s))
hex.EncodeToString(h.Sum(nil))

JSON

//数据转换为json字符串
json.Marshal(data)
//解析json
data := make(map[string]interface{})
json.Unmarshal([]byte(body), &data)

Database mysql operation

type User struct{
 Id int
 Name string
}
rows, err := db.Query("SELECT id,name FROM users")
var u User
for rows.Next(){
 rows.Scan(&u.Id, &u.Name)
}

{{o.name}}

{{m.name}}