【中间件go client系列】redis的go client使用

有时候需要对key值的进行统计，这时候就需要写个工具类。
用法如下：

./keys_count_tool -address 'ip:6379' -filename 'userinfo_key.txt' -findkeys '*_USERINFOCENTER_*'

代码如下：

package main

import (
	"flag"
	"fmt"
	"github.com/go-redis/redis"
	"os"
)

var address string
var filename string
var findkeys string

func init() {
	flag.StringVar(&address, "address", "redis server ip and port", "-address")
	flag.StringVar(&filename, "filename", "file name", "-filename")
	flag.StringVar(&findkeys, "findkeys", "find keys", "-findkeys")
}
func main() {
	flag.Parse()
	client := redis.NewClient(&redis.Options{
		Addr:     address,
		Password: "", // no password set
		DB:       0,  // use default DB
	})

	var cursor uint64
	var n int
	file, err := os.OpenFile(filename, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0777)
	if err != nil {
		fmt.Println("文件打开失败", err)
	}
	//及时关闭file句柄
	defer file.Close()
	for {
		var keys []string
		var err error
		//*扫描所有key，每次20条

		keys, cursor, err = client.Scan(cursor, findkeys, 20).Result()
		if err != nil {
			panic(err)
		}
		for _, key := range keys {
			data := key + "\n"
			n, err := file.Write([]byte(data))
			if err == nil && n < len(data) {
				fmt.Println("写入文件失败", err)
			}
		}
		n += len(keys)
		fmt.Printf("\nfound %d keys\n", n)
		if cursor == 0 {
			break
		}
	}
}