Newbie - Playing Around

rts1676 has asked for the wisdom of the Perl Monks concerning the following question:

I'm playing around with PERL, never used it before and find some of the example scripts I run across to be useful - while I'm gearing up to spare free cycles to learning how to code properly. However, I found one on this site that I'm trying to modify slightly: The following is code:

 
use strict;
use Net::Ping;

# Declare Var
my ($host, $x, $res);
my $output = '';

# Servers To Ping
my @AFIS = qw(
    mnbcamp001
    mnbcamp002
    mnbcamp003
    mnbcamp004
    mnbcamp005
);

# Ping Hosts Defined Above
sub ping_hosts {
    foreach $host (@AFIS) {
        my $p = Net::Ping->new("icmp");
        my $res = $p->ping($host);
        $output .= "Unknown $host\n" unless defined $res;
        if (!$res) {
            $output .= "$host Host is not reachable!\n";
        } else {
            $output .= "$host Host is reachable!\n"
        }
        
    }
}

ping_hosts;
# Print Results to Terminal
print $output;
[download]

The script itself works but what I'd like to have happen is two things: Since I have about 85 servers that will be pinged via this method, I'd like to supply it with a text file which has the server names and/or IPs in it and secondly I'd like to have it output the data into a text file, and, if it's not super hard to do email it.

That being said, I did manage to add the output to file element but it gave me an uninitialized value in concatenation error for $res

Added where seemed appropriate

my $outfile = "output.txt";

open (OUTFILE, ">> $outfile") || die "ERROR: opening $outfile\n"; 

chomp ($host);
   print OUTFILE "Results for $host:\n";
   print OUTFILE "$results\n\n";
[download]

Now, I'm a total newb, I'm just digging into this little bits at a time and playing around with things. Please, take it easy on me, I've got literature coming in the mail soon but figured why not ask a question and see what happens in the meantime. I appreciate any help I can get!

Comment on Newbie - Playing Around Select or Download Code

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Re: Newbie - Playing Around by marto (Cardinal) on Dec 29, 2015 at 15:12 UTC
Welcome! Firstly reading your server list from a file: `#!/usr/bin/perl use strict; use warnings; use Data::Dumper; my $serverfile = 'servers.txt'; open (my $fh, '<', $serverfile) or die "can't open file $serverfile: $ +!"; chomp(my @servers = <$fh>); close $fh; print Dumper @servers;` [download] In the above example I use the Data::Dumper module to print the array, you obviously don't need this part. Also note the use of `$!` to tell you why trying to open the file failed. For further info take a look at open. For sending mail I use the MIME::Lite module, example code in the documentation. "That being said, I did manage to add the output to file element but it gave me an uninitialized value in concatenation error for $res" Can you please post the exact error and the code which generates it? How do I post a question effectively? has tips on how to best achieve this around here.	[reply] [d/l] [select]
Re: Newbie - Playing Around by BillKSmith (Monsignor) on Dec 29, 2015 at 19:41 UTC
You do not have to wait for literature. If you have perl, you already have a great deal of quality documentation which you can read with the tool perldoc. To learn to use it, type: `perldoc perldoc` Bill	[reply] [d/l]
Re: Newbie - Playing Around by 1nickt (Canon) on Dec 29, 2015 at 14:55 UTC
... but figured why not ask a question ... So go ahead: ask a question. The way forward always starts with a minimal test.	[reply]
Re^2: Newbie - Playing Around by rts1676 (Initiate) on Dec 29, 2015 at 15:29 UTC
Indeed. Forgive my general lack of forum etiquette as I typically don't actively participate in them. When time allows I will post a better and more acceptable question in response here.	[reply]