expectperl-discuss

[Expectperl-discuss] Understanding interact

[Simon T. <si...@un...>]

Folks,

I am trying to understand the Expect.pm version of interact().

I have a telnet automation program written in tcl/expect that I am converting
to perl so that I can learn Expect.pm. The tcl version can telnet to a variety
of remote hosts, log in, handle any host-specific settings and then hand
control back to the user via interact:  

    send_user "$Prog: Handing control back to user on ${host}...\n";
    interact {
        "~~r" { send "tput rmso; clear\r" }
    }

This fragment does two nice things, 

  1) it looks for the "~~r" string from the user and responds to it and then 
      continues interacting, and 

  2) as soon as the spawned process exits, the interact loop ends.

I cannot start to get the equivalent functionality in the perl interact, ie:

    print "$prog: Handing control back to the user on $host...\n";
    $Expect::Log_Stdout=1;
    $telnet->interact(\*STDIN, "~~r");  

Am I doing something wrong?

Regards,

Simon Taylor
--
(+613 9568 2005)
Unisolve Pty Ltd 
Melbourne, Australia

Re: [Expectperl-discuss] Understanding interact

[Roland G. <r.g...@xs...>]

Simon Taylor wrote:
> I cannot start to get the equivalent functionality in the perl interact, ie:
> 
>     print "$prog: Handing control back to the user on $host...\n";
>     $Expect::Log_Stdout=1;
>     $telnet->interact(\*STDIN, "~~r");
> 
> Am I doing something wrong?

No, this is a bug in the interact routine which will be fixed in the
next release, which I hopefully will find time for after my
easter vacation next week.

I'm attaching a patch from Jorgen Wahlsten <jo...@ti...>
for those who need it in the meantime.

Happy Easter!

Roland
--
RGi...@cp...


*** Expect.pm   Wed Mar 21 17:01:43 2001
--- Expect.pm.DIST      Mon Feb 19 05:21:22 2001
***************
*** 1055,1063 ****
        foreach $escape_sequence (keys(%{${*$read_handle}{exp_Function}})) {
          print STDERR "Tested escape sequence $escape_sequence from ${*$read_handle}{exp_Pty_Handle}"if ${*$read_handle}{"exp_Debug"} > 1;
          # Make sure it doesn't grow out of bounds.
!         if ((defined(${*$read_handle}{"exp_Max_Accum"}) &&
!             (${*$read_handle}{"exp_Max_Accum"}) &&
!             (length($escape_character_buffer)) > ${*$read_handle}{"exp_Max_Accum"})) {
            $offset = length($escape_character_buffer) - ${*$read_handle}{"exp_Max_Accum"};
            $escape_character_buffer = substr($escape_character_buffer,$offset,${*$read_handle}{"exp_Max_Accum"});
          }
--- 1055,1061 ----
        foreach $escape_sequence (keys(%{${*$read_handle}{exp_Function}})) {
          print STDERR "Tested escape sequence $escape_sequence from ${*$read_handle}{exp_Pty_Handle}"if ${*$read_handle}{"exp_Debug"} > 1;
          # Make sure it doesn't grow out of bounds.
!         if ((defined(${*$read_handle}{"exp_Max_Accum"}) &&(length($escape_character_buffer)) > ${*$read_handle}{"exp_Max_Accum"})) {
            $offset = length($escape_character_buffer) - ${*$read_handle}{"exp_Max_Accum"};
            $escape_character_buffer = substr($escape_character_buffer,$offset,${*$read_handle}{"exp_Max_Accum"});
          }