Question

我有一个GoLang软件包，使用os.OpenFile和bufio.Reader从fifo读取和写入。在Linux上，读者被告知作者已关闭该文件。然而，在达尔文它永远不会收到EOF。

package main

import (
    "bufio"
    "fmt"
    "os"
    "time"
)

// @note This is used to get around bufio.Scanner erroring at large lines
func readln(r *bufio.Reader) (string, error) {
    var (
        isPrefix = true
        err      error
        line, ln []byte
    )

    for isPrefix && err == nil {
        line, isPrefix, err = r.ReadLine()
        ln = append(ln, line...)
    }

    return string(ln), err
}

func reader(filePath string) {
    f, err := os.Open(filePath)
    if err != nil {
        panic(err)
    }

    reader := bufio.NewReader(f)
    fmt.Print("READER >> created\n")

    line, readErr := readln(reader)

    for readErr == nil {
        fmt.Printf("READER >> read 1 line: %+v\n", line)
        line, readErr = readln(reader)
    }

    fmt.Printf("READER >> read finished: %+v\n", readErr)
}

func writer(filePath string) {
    f, err := os.OpenFile(filePath, os.O_WRONLY, 0600)

    fmt.Printf("WRITER << opened: %+v|%+v\n", f, err)
    if err != nil {
        panic(err)
    }

    fmt.Printf("WRITER << encoder created\n")

    for i := 0; i < 3; i++ {
        time.Sleep(1 * time.Second)
        _, err = f.WriteString(fmt.Sprint("line", i, "\n"))
        fmt.Printf("WRITER << written line%d, %+v\n", i, err)
    }

    time.Sleep(1 * time.Second)
    err = f.Close()
    fmt.Printf("WRITER << closed: %+v\n", err)
}

func main() {
    fifo := os.Args[1]

    fmt.Printf("STARTED %s\n", fifo)

    go writer(fifo)
    reader(fifo)

    fmt.Print("ALL DONE\n")
}

Here is a repository再现了这种情况。

OSX

go version go1.10 darwin/amd64
STARTED /var/folders/k_/zdt3jb2j7gx1rnf379k_51gh0000gn/T/tmp.ksHGLSvs/fifo
READER >> created
WRITER << opened: &{file:0xc42009e000}|<nil>
WRITER << encoder created
WRITER << written line0, <nil>
READER >> read 1 line: line0
WRITER << written line1, <nil>
READER >> read 1 line: line1
WRITER << written line2, <nil>
READER >> read 1 line: line2
WRITER << closed: <nil>
^C
signal: interrupt

的Linux

go version go1.10 linux/amd64
STARTED /tmp/tmp.6if4ZSWnZ8/fifo
READER >> created
WRITER << opened: &{file:0xc42008c000}|<nil>
WRITER << encoder created
WRITER << written line0, <nil>
READER >> read 1 line: line0
WRITER << written line1, <nil>
READER >> read 1 line: line1
WRITER << written line2, <nil>
READER >> read 1 line: line2
WRITER << closed: <nil>
READER >> read finished: EOF
ALL DONE

这是向读者表明作者已完成的正确方法吗？

bufio.Reader没有在达尔文FIFO上获得EOF

0 个答案: