----- Original Message -----
From: Tyson Sommer <[EMAIL PROTECTED]>
Date: Thursday, February 17, 2005 11:42 am
Subject: RE: Capturing the results from Expect with backtick
>
>
> > -----Original Message-----
> > From: glidden, matthew [EMAIL PROTECTED]
> > Sent: Thursday, February 17, 2005 10:15 AM
> > To: 'beginners@perl.org'
> > Subject: Capturing the results from Expect with backtick
> >
> > I'm using combined perl and Expect scripts to do the following:
> >
> > 1. ping a host using expect (for technical reasons, I've had
> > better luck using expect than perl here) 2. for each system
> > that responds to ping, perform a series of rsh commands via perl
> >
> > The expect script is this, where $hosts is a list of
> > potential names to
> > ping:
> >
> > foreach h $hosts {
> > spawn ping $h
> >
> > expect {
> > icmp_seq {
> > puts $h
> > exit 0
> > }
> > }
> > }
> >
> > puts ""
> > exit -1
> >
> > Calling the expect script looks like this, where $sName is
> > the system name:
> >
> > my $sPing = `./ping.exp $sName`;
> >
> > Later on, I check the results like this:
> >
> > if ($sPing ne '') {
> > print "$sPing is up";
> > [rsh commands]
> > } else {
> > print "$sName is down";
> > }
> >
> > When I run this from a terminal window, it returns the pinged
> > name and everything works fine. However, I need it automated,
> > so I set up a cron job.
> > The cron job never pings the hosts successfully--everything
> > returns as "down." My hunch is that it has to do with using
> > "puts" in Expect and backtick in perl--do they need a STDOUT
> > stream to work properly? How can I set this up to ping
> > properly while automated?
> >
> > Matthew
>
>
> You shouldn't need Expect. I've had great success with something
> like this
> (I'm sure there's a more condensed way to write it, but this works
> everytime):
>
>
> ...
>
> ### open ping command with filehandle so we can grab the STDERR (in
> case of Unknown Host) using the 2>&1 and pipe
> ### Also using switches to make ping faster and limit to only four
> pings -- tailor to suit your needs
> open (PINGTEST, 'ping -c 4 -i .2 -w 3 ' . $sName . ' 2>&1 |') || die
> "Can't run PING!!!\n";
>
> ### set $ping_data to result of <PINGTEST> using join() to put into
> scalar context
> my $ping_data = join ("", <PINGTEST>);
>
> ### print $ping_data if debugging (useful for checking results of
> open() above)
> print "\n$ping_data\n" if $debug;
>
>
> ######### Might have to change one or more of the following regexes
> ########
> ######### depending on how your system returns ping data
> ########
>
> ### search $ping_data string...
> if ( $ping_data !~ /bytes\sfrom/ ) { ### <-- REGEX HERE
>
> if ( $ping_data =~ /unknown\shost/ ) { ### <-- REGEX HERE
>
> ### ...and set $error if device unknown...
> $error = "$sName unknown!!\n";
>
> } elsif ( $ping_data =~ /100% loss/ ) { ### <-- REGEX HERE
>
> ### ...or set $error if device known but
> unreachable...
> $error = "$sName is down!!\n";
>
> }
> } else {
>
> ### ...or set $error to "successful" if we are
> $error = "$sName is up!\n";
> }
>
> ...
>
>
> If anyone can make this simpler, let me know!
Why not use Net::Ping module ?? Here is an example
#!PERL
use warnings;
use strict;
use Net::Ping;
my $pinger = Net::Ping->new("icmp") || die "error: $!\n";
my $host = "myhost";
if( $pinger->ping($host,2) ){
print "$host is online\n";
}
else{
print "$host is offline\n";
}
>
>
>
>
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