在golang中如何将exec.Cmd的stdout写入文件？

Question

我正在尝试运行shell命令,捕获stdout并将该输出写入文件.但是,我似乎错过了几个步骤,因为当程序存在时,我试图写的文件是空的.如何捕获命令的标准输出并将其写入文件？

package main

import (
    "bufio"
    "io"
    "os"
    "os/exec"
)

func main() {

    cmd := exec.Command("echo", "'WHAT THE HECK IS UP'")

    // open the out file for writing
    outfile, err := os.Create("./out.txt")
    if err != nil {
        panic(err)
    }
    defer outfile.Close()

    stdoutPipe, err := cmd.StdoutPipe()
    if err != nil {
        panic(err)
    }

    writer := bufio.NewWriter(outfile)

    err = cmd.Start()
    if err != nil {
        panic(err)
    }

    go io.Copy(writer, stdoutPipe)
    cmd.Wait()
}

Answer 1

感谢#go-nutsirc频道上的KirkMcDonald ,我通过分配输出文件来解决这个问题cmd.Stdout,这意味着stdout直接写入文件.它看起来像这样:

package main

import (
    "os"
    "os/exec"
)

func main() {

    cmd := exec.Command("echo", "'WHAT THE HECK IS UP'")

    // open the out file for writing
    outfile, err := os.Create("./out.txt")
    if err != nil {
        panic(err)
    }
    defer outfile.Close()
    cmd.Stdout = outfile

    err = cmd.Start(); if err != nil {
        panic(err)
    }
    cmd.Wait()
}

Answer 2

你需要刷新作者.添加以下内容:

    writer := bufio.NewWriter(outfile)
    defer writer.Flush()

Answer 3

您还可以使用:

cmd.Stdout = os.Stdout

它会将所有cmd输出重定向到OS的标准输出.