Re: Reusing ssh connection in my Lua script

[Gunnar Zötl <gz@...>]

Apologies for blowing my own horn here... If you're on a unix system, you may want to look at lpty. That's exactly the kind of thing I wrote it for.

Gunnar

Es ist keine Schande, vor Angst zu verblöden.

Am 16.10.2010 um 20:13 schrieb Alexander Gladysh <agladysh@gmail.com>:

> Hi, list!
> 
> I have a complex Lua "shell" script tool which executes a lot of
> commands remotely (see code below).
> 
> Now, I've come to the point where reistablishing ssh connection for
> each command costs too much time.
> 
> I wonder, if there is a way to safely reuse the connection?
> 
> I thought about setting up "ssh <host> bash" and piping commands to it
> -- but io.popen has only one direction... Also, what if I want to pipe
> in some data? It feels fragile.
> 
> I'm looking for a solution that will allow me to keep the interface of
> shell_exec_remote and shell_read_remote functions (if they'll start
> using upvalues, that's ok). (But if I can't keep the interface, no
> problem, I'll cope with that.)
> 
> Any advice?
> 
> Thanks,
> Alexander.
> 
> ----------------------
> 
> local shell_exec = function(command, ...)
>  return assert(os.execute(table.concat({command, ...}, " ")))
> end
> 
> local shell_read = function(command, ...)
>  local f = assert(io.popen(table.concat({command, ...}, " ")))
>  local result = f:read("*a")
>  f:close()
>  f = nil
>  return result
> end
> 
> local shell_exec_remote = function(host, command, ...)
>  return shell_exec(
>      "ssh", host, Q(table.concat({command, ...}, " ")) -- Q is a
> quotation function
>    )
> end
> 
> local shell_read_remote = function(host, command, ...)
>  return shell_read(
>      "ssh", host, Q(table.concat({command, ...}, " "))
>    )
> end
> 
> shell_exec_remote("my.host", "echo", "command1")
> shell_exec_remote("my.host", "echo", "command2")
> shell_exec_remote("my.host", "echo", "command2")
> -- ...
>