How to send a command while ssh_exec_wait is not finnished.

[JackHsueh]

I am using the ssh coding in a remote platform. With xshll, after connected, the prompt is [user@ip]$, and when I input command SCALAstart, it will be shift to scala platform with prompt scala>, and then I can input the comman of scala code to manipulate the data. But when I used the ssh_exec_wait in Rstudio, it also can get back the output in consol with scala>, But the function is endless, and I can not sent the comman to the scala> line, neither the new ssh_exec_wait function, nor the console input. So can I execute command withou waiting the returns, and execute new command while the last comman is running. And an additional function is prefer to return the out or error independently.

[jeroen]

I don't understand what you are asking. Can you please include example R code?

[JackHsueh]

Sorry if I wasn't clear. What I want is to operate the remote data in EMR with Spark Shell.

Typically, I use xshell to connect to the EMR server, after connected, the to the prompt symbol is [user@ip]$ , here I can execute the linux command interactively. when I input command SCALAstart (like input python in windows cmd and enable python command) , it will be shift to the Spark shell with prompt symbol scala>, and then I can input Scala code interactively, such as var i=1.

When I used ssh package, it can connect to the server successfully.

library(ssh)
session<-ssh_connect("user@ip",keyfile="e:\\user.pem")

Then I can execute the linux command successfully.

ssh_exec_wait(session, command = "date")

But when I execute the start command of spark shell,

ssh_exec_wait(session,command="SCALAstart")

it start up successfully and end with the symbol scala> wating for scala codes.

but I can not send new command to the server interactively. So, I guess it is because that the command ssh_exec_wait is just waiting the end mark of command SCALAstar (A red stop button is in top right conner of r studio consol window), and new command of Scala code is not allowed to input.

#invalid code after ssh_exec_wait(session,command="SCALAstart")
ssh_exec_wait(session, command = "var i=1")
var i=1
ssh_exec_wait(session, command = ":quit")
#in xshell, the codes below is valid after command: SCALAstart
var i=1
:quit

My question is "Can I input the scala code interactively during command SCALAstart is not finished? " like xshell, running on the spark shell prompt scala>, when SCALAstart running on the linux prompt[user@ip]$". (same as running python code under python prompt>>> with "python interpreter command" is just running on windows CMD prompt> . )

[jeroen]

Currently you can only run scripts, there is no way to setup an interactive shell. I'm actually surprised SCALAstart doesn't recognize that it is in a non-interactive shell and hence freezes waiting for user input. I'll open a new issue for this: https://github.com/ropensci/ssh/issues/23 but I won't be able to look at it any time soon.