Answer to password shell prompt in golang

git, go, linux

Solution

If a user is asked for a password in their shell, you can use golang to write to the io.Writer that is `os.Stdin`

Properly passing data on stdin to a command and receiving data from stdout of that command in golang

`os.Stdin` is a `os.File` created by

NewFile(uintptr(syscall.Stdin), "/dev/stdin")

And the password prompt will be reading from this file

You can execute `./passwordtest.sh` as in your question, and then write the password to `os.Stdin`, and the bash script should accept the bytes written by golang as the password.

Alternatively is actually a method for this in the `exec` package for the `Cmd` type.

- Use cmd to execute your shell script

- Input the password using stdin, or `cmd.StdinPip()`

- Read the shells output using `cmd.CombinedOutput()`

Cmd represents an external command being prepared or run.

https://golang.org/pkg/os/exec/#Cmd.StdinPipe

cmd := exec.Command("cat")
stdin, err := cmd.StdinPipe()
if err != nil {
    log.Fatal(err)
}

go func() {
    defer stdin.Close()
    io.WriteString(stdin, "values written to stdin are passed to cmd's standard input")
}()

out, err := cmd.CombinedOutput()
if err != nil {
    log.Fatal(err)
}

fmt.Printf("%s\n", out)

StdinPipe returns a pipe that will be connected to the command's standard input when the command starts. The pipe will be closed automatically after Wait sees the command exit. A caller need only call Close to force the pipe to close sooner. For example, if the command being run will not exit until standard input is closed, the caller must close the pipe.

Also, your `cmd` arguments shouldn't combine clone and the url, try instead

cmd := exec.Command(cmdb, "clone", url)

Problem

Original source

Related problems

• Properly passing data on stdin to a command and receiving data from stdout of that command in golang