golang 檔案分類

package main

import (

    "fmt"

)

func files(fs []string) <-chan string{

    c := make(chan string, 1000) //帶1000個緩衝的channel,1000個以內不會阻塞

    go func(){

        for _, f := range fs{

            c <- f

        }

        close(c)   //切片內所有檔案發送完畢，關閉

    }()

    return c

}

func filterSize(in <-chan string) <-chan string{

    c := make(chan string, 1000)  //帶1000個緩衝的channel,1000個以內不會阻塞

    go func (){

        for i := range in{

            fmt.Println("filter size got:", i)

            if i == "123.txt" || i == "456.txt"{

                c <- i

             }

    }

    close(c)

    }()

    return c

}

func main() {

    fmt.Println("file filter service")

    fs := []string{"123.txt","456.txt","789.txt","1222.txt"}

    c := filterSize(files(fs))

    for i := range c{ //阻塞main gorouting, 迴圈取channel中的資料，直到channel關閉

        fmt.Println("main got:", i)

    }

}

輸出: 

file filter service

filter size func got: 123.txt

filter size func got: 456.txt

filter size func got: 789.txt

filter size func got: 1222.txt

main got: 123.txt

main got: 456.txt