Regular expressions

[mark]

i am attempting to write a script using Net::Telnet. The script telnets to
a machine
logs in and issues a command to list the config. Tthe output of the command
pauses
about every screenfull and gives the user the prompt " --More-- ". The
script
contains the followin code to account fot the prompt.

$telnet->waitfor('/-\-More\-\- $/i');
$telnet->print('\s');

the script does not proceed past the " --More-- " prompt. this problems
seems to have stumpt me. does anyone have any suggestions for me?

Thanks
mark

[Eric Amick]

Re: Regular expressions

On Sun, 29 Jun 2003 21:05:50 -0500, "mark" <mark_evans029@ yahoo.com>
wrote:
[color=blue]
>i am attempting to write a script using Net::Telnet. The script telnets to
>a machine
>logs in and issues a command to list the config. Tthe output of the command
>pauses
>about every screenfull and gives the user the prompt " --More-- ". The
>script
>contains the followin code to account fot the prompt.
>
>$telnet->waitfor('/-\-More\-\- $/i');[/color]

Hyphens are special only within character classes, so I'd remove the
backslashes for readability if nothing else. Are you absolutely certain
the prompt ends with exactly one space?
[color=blue]
>$telnet->print('\s');[/color]

This looks suspicious. Shouldn't that be a space in the quotes? You
probably want put() instead of print(); print() sends out a newline
automatically, and you wouldn't press return when typing it manually.

--
Eric Amick
Columbia, MD

[mark]

Re: Regular expressions


"Eric Amick" <eric-amick@comcast.n et> wrote in message
news:t8cvfvgsnh cpqf9pfjkt1853j anjth9bne@4ax.c om...[color=blue]
> On Sun, 29 Jun 2003 21:05:50 -0500, "mark" <mark_evans029@ yahoo.com>
> wrote:
>[color=green]
> >i am attempting to write a script using Net::Telnet. The script telnets[/color][/color]
to[color=blue][color=green]
> >a machine
> >logs in and issues a command to list the config. Tthe output of the[/color][/color]
command[color=blue][color=green]
> >pauses
> >about every screenfull and gives the user the prompt " --More-- ". The
> >script
> >contains the followin code to account fot the prompt.
> >
> >$telnet->waitfor('/-\-More\-\- $/i');[/color]
>
> Hyphens are special only within character classes, so I'd remove the
> backslashes for readability if nothing else. Are you absolutely certain
> the prompt ends with exactly one space?
>[color=green]
> >$telnet->print('\s');[/color]
>
> This looks suspicious. Shouldn't that be a space in the quotes? You
> probably want put() instead of print(); print() sends out a newline
> automatically, and you wouldn't press return when typing it manually.
>
> --
> Eric Amick
> Columbia, MD[/color]


ya, i tried exactly one space prior to trying the /s. ya fairly certain it
is just one space. i was thought it might
be sending an unprintable character for what ever reason, so i changed
input_log to a dump_file and checked
the last character in it. the end of the file just one character with
character code 20. I just tried using the put in
place of the print, but didn't seem to help.

Thanks mark
mark

[Peter Pentchev]

Re: Regular expressions

"mark" <mark_evans029@ yahoo.com> wrote in message news:<F-SdnWyA54aWBmKjX TWJiw@www.bayou .com>...[color=blue]
> i am attempting to write a script using Net::Telnet. The script telnets to
> a machine
> logs in and issues a command to list the config. Tthe output of the command
> pauses
> about every screenfull and gives the user the prompt " --More-- ". The
> script
> contains the followin code to account fot the prompt.
>
> $telnet->waitfor('/-\-More\-\- $/i');
> $telnet->print('\s');
>
> the script does not proceed past the " --More-- " prompt. this problems
> seems to have stumpt me. does anyone have any suggestions for me?[/color]

There could be several problems here.

First, input buffering could pose a problem. The Net::Telnet documentation
explicitly states that all input is buffered; in my limited testing,
the waitfor() method does indeed return lines that do *not* end with an
end-of-line, but I am not sure that this will always be the case.
In other words, the problem could be Net::Telnet's waitfor() not returning
until a whole line has been read, and the --More-- prompt does not really
contain a CR/LF at the end.

Second, are you sure that the string you should be matching for is
the exact sequence of characters '-', '-', 'M', 'o', 'r', 'e', etc?
I mean, some pagers use the "backspace convention" (for lack of a better
name that I can think of right now) to indicate bold, underline and such:
for bold, the pager outputs 'M', backspace, 'M'; for underline, it prints
'_', backspace, 'M'. If the '--More-- ' prompt is bold for some reason,
then '--More-- ' will probably not match it.

Those are two reasons that I can think of offhand.

G'luck,
Peter

[adey]

Re: Regular expressions

On Sun, 29 Jun 2003 21:05:50 -0500, "mark" <mark_evans029@ yahoo.com>
wrote:
[color=blue]
>i am attempting to write a script using Net::Telnet. The script telnets to
>a machine
>logs in and issues a command to list the config. Tthe output of the command
>pauses
>about every screenfull and gives the user the prompt " --More-- ". The
>script
>contains the followin code to account fot the prompt.
>
>$telnet->waitfor('/-\-More\-\- $/i');
>$telnet->print('\s');
>
>the script does not proceed past the " --More-- " prompt. this problems
>seems to have stumpt me. does anyone have any suggestions for me?
>
>Thanks
>mark
>
>[/color]
Hi Mark,

I use the module all the time. The non Perl solution to your problem
is this;

I would suggest you command the machine to dump the whole of the
config in one go.

For instance, if you are attempting to list the config on a Cisco
router, you could issue the command "term len 0" prior to issuing the
command to list the config.

Adey