smartpty

SmartPTY Golang library

SmartPTY is a simple expect/pexpect like library for go which makes you able to start a terminal with a standard exec.Cmd inside and react to certain expressions coming from the terminal output.

The most obvious way you can use it is starting a shell or a ssh session and make it type password for you automatically. You can find sudo.go in examples folder which does exactly that.

Methods

func Create(*exec.Cmd) *SmartPTY creates a smartpty object based on the given Cmd

func (sp *SmartPTY) Start() error starts the terminal. Be sure to configure reaction callbacks before calling Start()

func (sp *SmartPTY) Close() closes the terminal and stops all the goroutines. This is not very useful as you can always call myCmd.Process.Kill() which will close related file descriptors and SmartPTY goroutines processing stdin/stdout should then stop automatically.

func (sp *SmartPTY) Once(expr *regexp.Regexp, cb ExpressionCallback)

func (sp *SmartPTY) Always(expr *regexp.Regexp, cb ExpressionCallback)

func (sp *SmartPTY) Times(expr *regexp.Regexp, cb ExpressionCallback, int times)

These functions create a reaction callback based on expr argument. When SmartPTY finds a chunk of data matching the expression, the cb function is called. The difference between these functions are kinda self-explanatory: Once() will run the callback just once, Always() will run its callback every time SmartPTY receives the matching chunk of data, and Times() will react exactly times times.

type ExpressionCallback func(data []byte, tty *os.File) []byte This is the callback function signature. SmartPTY will pass the whole data chunk matching the expression, the pseudo-terminal *os.File object where you can respond to using tty.Write([]byte). In the end of each callback you can either return the whole chunk (return data) or modify it as you wish to, for example you may want to remove the "Password:" prompt from the output.