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From: Hailey N. <Hai...@Su...> - 2003-10-01 18:09:00
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Hi,
Please show me how to do nested telnet sessions using Expect.pm module?
1- telnet to machine A
2- from A to mcahine B
3- from M to another machine C
-----
use Expect;
my $exp = Expect->spawn("telnet $somehost")
or die "Cannot spawn telnet: $!\n";
...
-----
Your help is greatly appreciated. Please reply directly to me since
I am not on the alias.
Hailey.
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From: Chris M. <mut...@mc...> - 2003-10-01 19:05:56
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Hey,
First you will have to login to A. That involves what you have, plus you=
will have to $exp->expect() for
whatever telnet responds with when it asks for the password. Then use a=
$exp->send() to send the password.
Then $exp->expect() for the prompt on A. Once you are logged into A, use a=
$exp->send() to call telnet $B on A to login to
B, $exp->expect() for the password prompt, and then $exp->send() it. Once=
logged into B, do the same to login to C, and
the same for D, and the same for ...
-Chris
On 10/1/03 at 11:07 AM Hailey Nguyen wrote:
>Hi,
>
>Please show me how to do nested telnet sessions using Expect.pm module?
>
>1- telnet to machine A
>2- from A to mcahine B
>3- from M to another machine C
>
>-----
>use Expect;
>
>my $exp =3D Expect->spawn("telnet $somehost")
> or die "Cannot spawn telnet: $!\n";
>
>...
>
>-----
>Your help is greatly appreciated. Please reply directly to me since
>I am not on the alias.
>
>Hailey.
>
>
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From: Hailey N. <Hai...@Su...> - 2003-10-01 20:33:58
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Hi Chris,
Thanks so much for the help! I was able to telnet into the hostA then
the next one it keeps looping around the statement below and won't
quit. If I take out the "\n"" character it won't loop but it won't
go further either.
$fh->send("telnet $hostsB\n";
Help Help Help ... thanks again.
H
-----------
!/bin/perl
use Expect;
$Expect::Log_Stdout = 1;
# variables define here
# ...
my $exp = Expect->spawn("telnet $hostA")
or die "Cannot spawn telnet: $!\n";
my $spawn_ok;
$exp->log_file("testlog");
$exp->expect($timeout,
[
qr'login: $',
sub {
$spawn_ok = 1;
my $fh = shift;
$fh->send("$username\n");
exp_continue;
}
],
[
'Password: $',
sub {
my $fh = shift;
print $fh "$password\n";
exp_continue;
}
],
[
'# $',
sub {
$spawn_ok = 1;
my $fh = shift;
$fh->send("telnet $hostB\n"); <================
exp_continue;
}
],
[
'login: $',
sub {
my $fh = shift;
print $fh "$username\n";
exp_continue;
}
],
[
'Password: $',
sub {
my $fh = shift;
print $fh "$password\n";
exp_continue;
}
],
[
eof =>
sub {
if ($spawn_ok) {
die "ERROR: premature EOF in login.\n";
} else {
die "ERROR: could not spawn telnet.\n";
}
}
],
[
timeout =>
sub {
die "No login.\n";
}
],
'-re', qr'[#] $' # wait for shell prompt, then exit expect
);
$exp->hard_close();
-------------------------
>
> First you will have to login to A. That involves what you have, plus you
> will have to $exp->expect() for whatever telnet responds with when it
> asks for the password. Then use a $exp->send() to send the password.
> Then $exp->expect() for the prompt on A. Once you are logged into A, use
> a $exp->send() to call telnet $B on A to login to B, $exp->expect() for
> the password prompt, and then $exp->send() it. Once logged into B, do
> the same to login to C, and the same for D, and the same for ...
>
> -Chris
>
>
> On 10/1/03 at 11:07 AM Hailey Nguyen wrote:
>
>> Hi,
>>
>> Please show me how to do nested telnet sessions using Expect.pm module?
>>
>> 1- telnet to machine A
>> 2- from A to mcahine B
>> 3- from M to another machine C
>>
>> -----
>> use Expect;
>>
>> my $exp = Expect->spawn("telnet $somehost")
>> or die "Cannot spawn telnet: $!\n";
>>
>> ...
>>
>> -----
>> Your help is greatly appreciated. Please reply directly to me since
>> I am not on the alias.
>>
>> Hailey.
>>
>>
>
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From: Hailey N. <Hai...@Su...> - 2003-10-02 20:13:10
|
Hi Chris,
>>> First you will have to login to A. That involves what you have, plus
>>> you will have to $exp->expect() for whatever telnet responds with when
>>> it asks for the password. Then use a $exp->send() to send the password.
>>> Then $exp->expect() for the prompt on A. Once you are logged into A,
>>> use a $exp->send() to call telnet $B on A to login to B, $exp->expect()
>>> for the password prompt, and then $exp->send() it. Once logged into B,
>>> do the same to login to C, and the same for D, and the same for ...
Still struggling with this. As soon as I logged into B from A I lose
control of that session/connection. So $exp->send() won't do anything.
Did you write something like this before. Can I have an example?
Note: A know B but doesn't know C - in another words, to get to C you have
to go through B.
Thanks a million,
Hailey
>>>>
>>>> Please show me how to do nested telnet sessions using Expect.pm module?
>>>>
>>>> 1- telnet to machine A
>>>> 2- from A to mcahine B
>>>> 3- from B to machine C
>>>>
>>>> -----
>>>> use Expect;
>>>>
>>>> my $exp = Expect->spawn("telnet $somehost")
>>>> or die "Cannot spawn telnet: $!\n";
>>>>
>>>> ...
>>>>
>>>> -----
>>>> Your help is greatly appreciated. Please reply directly to me since
>>>> I am not on the alias.
>>>>
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From: Chris M. <mut...@mc...> - 2003-10-02 22:21:08
|
Hi,
>Did you write something like this before. Can I have an example?
Yes I did. Sure, here it is.
This is more than an example, It is a fully working implementation of a so=
called "looping login" scheme.
It works for an arbitrary number of hosts. It was also designed to work=
with ssh, and not telnet.
You will have to go through and make the relevant changes to make it work=
with telnet.
Optionally, you might consider using ssh -if possible-, as it is more=
secure than telnet.
This will log you into all of the given hosts and leave you with a $exp=
that is valid on the final host.
This is a subroutine. The usage explanation of it is at the bottom of the=
code segment.
I hope this helps.
-Chris Muth
####
#### START OF CODE
####
#!/usr/bin/perl5.8 -w
use Expect; # for scripted I/O
# req global; $exp, $number_of_hosts, $hostname[], $password[],
sub multi_login {
my($i,$j);
for ($i=3D0;$i<$number_of_hosts;$i++){
if ($i=3D=3D0){
$exp->spawn("/usr/local/bin/ssh",$hostname[$i]);
} else {
$exp->send("/usr/local/bin/ssh ".$hostname[$i]."\n");
}
$retval =3D $exp->expect(30,'-re','word:\s$','Connection refused','No=
route to host','Name or service not known');
if (defined $retval){
if ($retval !=3D 1) { # $retval is 2 or 3.
if ($retval =3D=3D 2){ # $retval is 2, "Connection refused".
if ($i > 0){
for ($j=3D0;$j<$i;$j++){
$exp->send("logout\n");
}
}
print "connection refused for ".$hostname[$i];
$exp->hard_close();
exit 1;
} else {
if ($retval =3D=3D 3){ #$retval is 3, "No route to host".
if ($i > 0){
for ($j=3D0;$j<$i;$j++){
$exp->send("logout\n");
}
}
print "there is no route to host ".$hostname[$i];
$exp->hard_close();
exit 1;
} else { # $retval is 4, 'Name or sevice not known'
if ($i > 0){
for ($j=3D0;$j<$i;$j++){
$exp->send("logout\n");
}
}
print "Name or service not known for host=
".$hostname[$i];
$exp->hard_close();
exit 1;
}
}
} # $retval is 1, we got the password prompt.
} else { # $retval is undefined, ssh didn't respond with anything=
within 30 seconds.
if ($i > 0){
for ($j=3D0;$j<$i;$j++){
$exp->send("logout\n");
}
}
print "ssh did not respond";
$exp->hard_close();
exit 1;
}
$exp->send($password[$i]."\n");
$retval =3D $exp->expect(30,'# ','Permission denied');
if (defined $retval){
if ($retval =3D=3D 2){ # $retval is 2, we got a permission denied=
message.
if ($i > 0){
for ($j=3D0;$j<$i;$j++){
$exp->send("logout\n");
}
}
print "permission denied for login to ".$hostname[$i];
$exp->hard_close();
exit 1;
} # $retval is 1, we got the prompt.
} else { # Got neither a prompt, nor a permission deined message.
if ($i > 0){
for ($j=3D0;$j<$i;$j++){
$exp->send("logout\n");
}
}
print "error on login to ".$hostname[$i];
$exp->hard_close();
exit 1;
}
}
}
# instiantiate an Expect object that we will use.
$exp =3D new Expect;
$exp->raw_pty(1);
# for use by multi_login(), how many hosts to login to.
$number_of_hosts =3D 3;
# List all of the hosts to login to. Start at 0.
$hostname[0] =3D 'host0';
$hostname[1] =3D 'host1';
$hostname[2] =3D 'host2';
# List all of the passwords for the hosts to be logged into. Again, start=
at 0.
$password[0] =3D 'pass0';
$password[1] =3D 'pass1';
$password[2] =3D 'pass2';
# Call multi_login(), it will use $exp, $number_of_hosts, $hostname[], and=
$password[].
multi_login();
# From here on out, $exp is valid on hostname[<max>].
# Just use it as normal.
# Modify the prompt to something easy to match, and easy on bandwidth.
$exp->send("PS1=3D\"# \"\nexport PS1\n");
$exp->expect(30,'# ');
$exp->expect(30,'# ');
$exp->send("ls -l\n");
$exp->expect(30,'# ');
# this will make expect wait, as sleep() does not work with expect scripts.
$exp->expect(5,'this call will make expect sleep');
$exp->hard_close();
print "\n";
exit 0;
#####
##### END OF CODE
#####
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From: Hailey N. <Hai...@Su...> - 2003-10-03 01:23:09
|
I can't thank you enough! Made my day - wait my week actually! Thank You so much Chris, Hailey >> Did you write something like this before. Can I have an example? > Yes I did. Sure, here it is. > > This is more than an example, It is a fully working implementation of a > so called "looping login" scheme. It works for an arbitrary number of > hosts. It was also designed to work with ssh, and not telnet. You will > have to go through and make the relevant changes to make it work with > telnet. Optionally, you might consider using ssh -if possible-, as it is > more secure than telnet. > > This will log you into all of the given hosts and leave you with a $exp > that is valid on the final host. > > This is a subroutine. The usage explanation of it is at the bottom of > the code segment. > > I hope this helps. > |
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