Unexpected Input Echo in Output When Using pty

[cuijixiong1]

I encountered an issue when using the github.com/creack/pty library to create a pseudo-terminal. Below is the relevant code snippet:

cmd := exec.Command("/system/bin/sh")

// Allocate a pseudo-terminal for the subprocess
ptyMaster, err := pty.Start(cmd)
if err != nil {
return ErrPkg.NewErrD("Failed to start shell: " + err.Error())
}

When I send a command (e.g., ls followed by Enter) to the subprocess through the pseudo-terminal and then read the output, the output includes not only the command's execution result but also the command input itself. For example:

Input: ls
Output: ls\n + the actual command output

This behavior results in the output containing the input content, which is unexpected. I expect to receive only the command's execution result without the input echoed back.

Could you clarify if this behavior is intentional or if there's a way to avoid this echo in the output?

[creack]

This is indeed expected and has to do with the terminal, no directly the pty library.
If you take a look at the README, there is an example of a shell, the key part you are looking for is

        // Set stdin in raw mode.
        oldState, err := term.MakeRaw(int(os.Stdin.Fd()))
        if err != nil {
                panic(err)
        }
        defer func() { _ = term.Restore(int(os.Stdin.Fd()), oldState) }() // Best effort.

That will pass through the terminal management to the underlying process.

If you only want to disable the output showing the input you can just disable ECHO and/or ICANON termios