Golang - Unable to get results from pipped Windows command

user_19474295 0
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I am struggling to get the output for a Windows command that has a pipe in it. Here is the command:

systeminfo | findstr /B /C:"OS Name"

Here is the code:

c1 := exec.Command("systeminfo")
c2 := exec.Command("findstr", "/B", `/C:"OS Name"`)

r, w := io.Pipe()
c1.Stdout = w
c2.Stdin = r

var b2 bytes.Buffer
c2.Stdout = &b2

c1.Start()
c2.Start()
c1.Wait()
w.Close()
c2.Wait()
io.Copy(os.Stdout, &b2)
fmt.Println(b2)

Output: []

If I copy/paste the command in cmd, it will return results. Not sure why I can't get that reflected in my Go programme. I tried several variants, including the addition of "cmd", "/C" in the first command but no success either.

go command cmd pipe
1 Answers

Remove the io.Copy to no redirect to STDOUT and print the content of the buffer.

    systemCmd := exec.Command("systeminfo")
    findCmd := exec.Command("findstr", "/B", "/C:OS Name")

    reader, writer := io.Pipe()
    buf := bytes.NewBuffer(nil)
    systemCmd.Stdout = writer
    findCmd.Stdin = reader
    findCmd.Stdout = buf
    systemCmd.Start()
    findCmd.Start()
    systemCmd.Wait()
    writer.Close()
    findCmd.Wait()
    reader.Close()

    fmt.Println(">>" + buf.String())

ie:

PS C:\Users\user\Documents> go run .\main.go
>>OS Name:                   Microsoft Windows 10 Pro
user_132221540
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