Question

I’m trying a new approach to a hitch I’ve been stuck on. Instead of using expect4j for my SSH connection, (I couldn’t figure out a way past blocking consumer runs and issues with closures, see past posts for more info on that if you’re knowledgeable and feeling saintly,) I’m going to try to use an expect script. I have a runtime exec coded in to a button.onclick, see below. Why am I getting a 127 exit value? I basically just need this expect script to ssh in, run a single set of expect and send, give me the readout, and that’s it…

I’m using cygwin. Not sure if that’s relevant to why this isn’t working…is my sh-bang line pointing to the right place? My cygwin install is a full install, all packages, in C:\cygwin.

Why am I getting a 127 exit value instead of a readout from my server, and how do I alleviate this?

try
    {            
        Runtime rt = Runtime.getRuntime();
        Process proc = rt.exec( new String [] {"C:\\cygwin\\bin\\bash.exe", "C:\\scripts\\login.exp"});
        InputStream stdin = proc.getInputStream();
        InputStreamReader isr = new InputStreamReader(stdin);
        BufferedReader br = new BufferedReader(isr);
        String line = null;
        System.out.println("<OUTPUT>");
        while ( (line = br.readLine()) != null)
            System.out.println(line);
        System.out.println("</OUTPUT>");
        int exitVal = proc.waitFor();            
        System.out.println("Process exitValue: " + exitVal);
    } catch (Throwable t)
      {
        t.printStackTrace();
      }







#!/usr/bin/expect -f
spawn ssh [e-mail] password
match_max 100000
expect "/r/nDestination: "
send -- "xxxxxx\r"
expect eof

Answer 1

The problem is that you use bash to execute an expect script. You need to use expect to execute an expect script, or bash to execute an expect script by means of a shell commandline (that would be Process proc = rt.exec( new String [] {"C:\\cygwin\\bin\\bash.exe", "-c", "C:\\scripts\\login.exp"});, note the "-c" which I have inserted) which makes use of the magic shebang at the top of your script. Or better, use only the shebang: Process proc = rt.exec( new String [] {"C:\\scripts\\login.exp"});

The exit value of 127 is a special exit value, and tells you “command not found”. Which makes sense as you expect script contains many words for which no system binaries or shell builtins exist.