expectperl-discuss

[Expectperl-discuss] trapping remote shell stderr

[Ryan A. <r....@f5...>]

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

RE: [Expectperl-discuss] trapping remote shell stderr

[Tracie F. <tra...@tr...>]

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

 

 

 

 

 

Re: [Expectperl-discuss] trapping remote shell stderr

[Roland G. <RGi...@cp...>]

> 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