go-文件读写-db

目的

1 写一个文件字符串的小型db，将ueerid写入文件，下次再次写入时，先查找有无 2 读出时比对，读的时候是使用一行一行读的，这里如此使用是因为还要扩展到多个字段，现在是一个字段 3 暂时不使用算法，等下次需求再扩展

show me the code

注：写入时一定要每个写入"\n"

package main

import (
	"bufio"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"strings"
)

//注意写入时一定要写入一个\n
func User_Write(img_paths string, userid string) error {
	fd, _ := os.OpenFile(img_paths+"user.txt", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
	defer fd.Close()
	fd_byte, err := ioutil.ReadAll(fd)

	if err != nil {
		return err
	}
	fstring := string(fd_byte)
	ff := userid + "\n"
	if strings.Contains(fstring, ff) {
		return nil
	}
	fd_content := strings.Join([]string{userid, "\n"}, "")
	buf := []byte(fd_content)
	fd.Write(buf)
	return nil
}

func User_Read_Compare(paths string, userid string) int {
	//先获取到文件信息
	fileinfo, err := os.Stat(paths)
	if err != nil {
		return -1
		//return fmt.Errorf("get file info error")
	}
	if fileinfo.IsDir() {
		return -2
		//return fmt.Errorf("paths is dir")
	}
	f, err := os.Open(paths)
	defer f.Close()
	rd := bufio.NewReader(f)
	for {

		line, err := rd.ReadString('\n')

		if err != nil || err == io.EOF {
			if err != nil {
				return -3
				//return fmt.Errorf("ReadString error")
			}
			break
		}
		line = strings.Trim(line, "\n")
		if strings.Compare(line, userid) == 0 {
			//fmt.Printf("it has the userid")
			return 1
		}
		fmt.Printf("now the user is %s\n", line)
	}
	return 0
}


//unit test
func main() {
	fmt.Printf("read the user.txt\n")
	User_Write("./", "guanzhi")
	User_Write("./", "guanzhi2")
	User_Write("./", "qianbo")
	partten := "qianbo"
	if User_Read_Compare("./user.txt", partten)