expectperl-discuss Mailing List for Expect.pm

> Here=92s my problem.  I spawn a ssh session to a remote box, and run a=20
> command.   If the command is successful, I just get a new prompt, but i=
f
> it fails, the program spits out an error on STDERR.  Currently,=20
> $exp_object->exp_before(),$exp_object->match(), and my=20
> $exp_object->exp_after() objects contain all the STDOUT info, but no=20
> STDERR info.  How does one trap the STDERR strings?

What fails? The ssh shell connection? Or the remote call? Expect=20
definitely gets everything that ssh returns on both STDOUT and STDERR.=20
It may miss things to /dev/tty on some systems in certain circumstances.

> On a side note, is there a simple way to get the bash return code from =
a=20
> command sent to a spawned ssh shell?  Right now I=92m doing a =93echo $=
?=94=20
> and expecting =93\d\r=94 and parsing the string in $exp_object->match()=
;

If the ssh is interactive, no. Keep using "echo $?". A one-shot ssh=20
command will correctly exit with the exit status of the remote command=20
(but you wouldn't use Expect then, would you?)

Have you considered solving your problem by other means? Is the remote=20
app really interactive or could it also be run in a batchfile? How about=20
moving the Expect script to the remote host and running it there?

Roland

Why not do 2>&1? Redirect stderr to stdout?

 

-----Original Message-----
From: exp...@li...
[mailto:exp...@li...] On Behalf Of
Ryan Allen
Sent: Thursday, June 10, 2004 9:08 PM
To: exp...@li...
Subject: [Expectperl-discuss] trapping remote shell stderr

 

Hello perl expect list,

 

Please forgive is this is totally obvious, but I've been searching books
and on-line searches way too long!

 

Here's my problem.  I spawn a ssh session to a remote box, and run a
command.  If the command is successful, I just get a new prompt, but if
it fails, the program spits out an error on STDERR.  Currently,
$exp_object->exp_before(),$exp_object->match(), and my
$exp_object->exp_after() objects contain all the STDOUT info, but no
STDERR info.  How does one trap the STDERR strings?

 

On a side note, is there a simple way to get the bash return code from a
command sent to a spawned ssh shell?  Right now I'm doing a "echo $?"
and expecting "\d\r" and parsing the string in $exp_object->match();

 

Thanks!!

 

- Ryan

 

 

 

 

 

Hello perl expect list,

=20

Please forgive is this is totally obvious, but I've been searching books
and on-line searches way too long!

=20

Here's my problem.  I spawn a ssh session to a remote box, and run a
command.  If the command is successful, I just get a new prompt, but if
it fails, the program spits out an error on STDERR.  Currently,
$exp_object->exp_before(),$exp_object->match(), and my
$exp_object->exp_after() objects contain all the STDOUT info, but no
STDERR info.  How does one trap the STDERR strings?

=20

On a side note, is there a simple way to get the bash return code from a
command sent to a spawned ssh shell?  Right now I'm doing a "echo $?"
and expecting "\d\r" and parsing the string in $exp_object->match();

=20

Thanks!!

=20

- Ryan

=20

=20

=20

=20

=20

> -----Original Message-----
> From: exp...@li... 
> [mailto:exp...@li...] On 
> Behalf Of Peter Eisch
> Sent: Tuesday, June 01, 2004 12:53 PM
> To: exp...@li...
> Subject: Re: [Expectperl-discuss] My tty drama
> 
> 
> 
> It appears that last last week I became a bit overzealous in 
> my desire to be done with the project, so I'm back to it again.
> 
> OS: RH7.3
> Process gets started from an init.d script which uses the 
> daemon() found in the init.d/functions to run as non-priv'd 
> user. The first thing my parent does is typical W Richard Stevens:
>     close(STDIN);
>     close(STDOUT);
>     close(STDERR);
>     POSIX::setsid();
>     chdir("/");
>     ...

  As an aside, there's a module out there to do all that for you, if you
like.  I believe it's called Proc::Daemon.

jdb

It appears that last last week I became a bit overzealous in my desire to be
done with the project, so I'm back to it again.

OS: RH7.3
Process gets started from an init.d script which uses the daemon() found in
the init.d/functions to run as non-priv'd user.
The first thing my parent does is typical W Richard Stevens:
    close(STDIN);
    close(STDOUT);
    close(STDERR);
    POSIX::setsid();
    chdir("/");
    ...

Then eventually it comes around to me where I:
use Expect;
...
    $self->{_exp} = new Expect;
    $self->{_exp}->raw_pty(1);
...
    my @cmd = '/usr/bin/ftps';
    push @cmd, '-e';
    push @cmd, '-P', $self->{_port};
    push @cmd, '-d' if ($self->{_debug});
    push @cmd, '-p' if ($self->{_passive});
    push @cmd, '-n' if ($self->{_autologin});
    push @cmd, $self->{'_host'};
    my $c = join ' ', @cmd; #becomes: /usr/bin/ftps -e -P 21 <host>
    $exp->log_file("/tmp/exp-$$", 'w') if ($DEBUG);
    $exp->spawn(@cmd) ||
        return 0;
    $exp->expect($self->{_timeout},
                 [ qr/Name /i => sub { my $self = shift;
                                          $self->send($user . "\n");
                                          exp_continue; }],
                 [ qr/Password:/i => sub { my $self = shift;
                                          $self->send($pass . "\n");
                                          exp_continue; }],
                 $self->{_prompt});


And it's here that I time out never getting authenticated.  In fact exactly
nothing is written to the /tmp/exp-$$ file.

If I run the same script, called the same, from a tty as the user that
daemon() sets to, it works swell.

I'm open to any thoughts, ideas, criticisms, etc.

peter





> From: Austin Schutz <te...@of...>
> Date: Fri, 28 May 2004 10:35:56 -0700
> To: Peter Eisch <pe...@bo...>
> Cc: exp...@li...
> Subject: Re: [Expectperl-discuss] My tty drama
> 
> On Fri, May 28, 2004 at 11:35:24AM -0500, Peter Eisch wrote:
>> 
>> Yes, the difference is whether it runs as root or not.  In fact, if I pull
>> out all the tty calls except for raw_tty(1) and don't run as root it all
>> chugs along just fine.
>> 
>> My calls to expect() were messy to, my lesson for 'self' this morning is
>> don't expect '' before sending the command, just stinking send the command.
>> 
>> It just started working here in the last 20 mins and I have some stuff to do
>> before I can get back to cleaning this up, but I'll fire off a redux when I
>> can.
>> 
> 
> Btw, what type of system are you trying to run this on?
> 
> Austin
> 
> 
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