Terminal command support for z/OS

[fswarbrick]

So I've almost got the terminal command interface working for z/OS. The one remaining issue is the fact that z/OS, unlike other POSIX systems, does not prepend a CR (\r) before the LF (\n) when reading(?) from a pseudo-terminal. The effect is that new lines start "indented" to the position the previous line ended. Here is an example:

I've found somewhat of a solution, but I'm not sure the best way to make it implemented for zos only. This is what I've done so far.

index 6fb1ce7f..7598daa5 100644
--- a/internal/shell/terminal.go
+++ b/internal/shell/terminal.go
@@ -93,6 +93,9 @@ func (t *Terminal) Start(execCmd []string, getOutput bool, wait bool, callback f
                callback(out, userargs)
        }

+       // set CRLF mode (for z/OS only)
+       Term.Write([]byte("\033[20h"))
+
        go func() {
                for {
                        err := Term.Parse()

This works fine, but would be done for all systems, not just z/OS.
It seems kind of crazy to add a new set of files (crlf_zos.go and crlf_other.go, or something like this) with a single method. But that seems to be the way to go. Is there a better way? Or would it be OK to do it for all systems. I'm not sure that having just an LF do what it's doing now ever makes sense.