hmb104 has asked for the wisdom of the Perl Monks concerning the following question:

Dear Monks,

I'm getting about 10 lines when I perform a query on a Cisco router. From these 10 lines I need the some info from the first 3 lines. Hwo I can use the split function on ONLY the first 3 lines of the array? Below is my Code: 

@Data = split( ' ', $RouterOutput[0,2] );
if ( ( $Data[0] eq 'Device' ) && ( $Data[1] eq 'ID:' ) ) {
   $SwitchName = $Data[2] ;
   $SwitchName =~ s/$'site.com'//i ;
}
if ( ( $Data[0] eq 'IP' ) && ( $Data[1] eq 'address' ) ) {
   $SwitchIP = $Data[2] ;
}

[download]

Replies are listed 'Best First'.
Re: Split() first 3 elements of @array
by philiprbrenan (Monk) on Aug 28, 2012 at 18:46 UTC

    Select the first 3 elements of an array as:

     @array[0..2]

    [download]

    exerting care in case there are less than 3 elements.

    use feature ":5.14";
use warnings FATAL => qw(all);
use strict;
use Data::Dump qw(dump);

my @RouterOutput = split /\n/, << 'END';
1 AAAA BBBB CCCC
2 AAAA BBBB CCCC
3 AAAA BBBB CCCC
4 AAAA BBBB CCCC
END

for(@RouterOutput[0..2])
 {say "@{[split]}[0,3,2,1]" if $_;
 }

    [download]

    Produces

    1 CCCC BBBB AAAA
2 CCCC BBBB AAAA
3 CCCC BBBB AAAA
[reply]
[d/l]
[select]

      Thanks for the suggestions. I have tried 2 ways and I still can't get some of the info. Lets assume the lines that I store at my @array are the following:

      Device ID: switch1.Core-3750.abc.com
Entry address(es):
  IP address: 10.10.10.10
Platform: cisco WS-C3750G-12S,  Capabilities: Router Switch IGMP
Interface: GigabitEthernet1/0/28,  Port ID (outgoing port): GigabitEth
+ernet2/0/7
Holdtime : 145 sec

Version :
Cisco IOS Software, C3750 Software (C3750-IPSERVICESK9-M), Version 12.
+2(55)SE4, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2011 by Cisco Systems, Inc.
Compiled Tue 06-Sep-11 02:59 by prod_rel_team

advertisement version: 2
Protocol Hello:  OUI=0x00000C, Protocol ID=0x0112; payload len=27, val
+ue=00000000FFFFFFFF01022507000000000000A8B1D400F080FF0000
VTP Management Domain: 'networks'
Native VLAN: 1
Duplex: full

      [download]

      I can extract the switch name but I cannot sxtract the IP address for the switch for some reason

          foreach $Line ( @RouterOutput ) {
        if ( $Line =~ m/^Device / ) {
            @Data = split( ' ', $Line );
            $SwitchName = $Data[ 2 ] ;
            last ;
        }
        if ( $Line =~ m/^IP / ) {
            @Data = split( ' ', $Line );
            $SwitchIP = $Data[ 2 ] ;
            last ;
        }
    }

      [download]
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[d/l]
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        I cannot sxtract the IP address for the switch for some reason

        The third line, with the IP address is indented: there is some whitespace at the beginning of the line, but your regular expression is looking for 'IP' at the beginning of the line: /^IP/. Change that to accept some leading whitespace and you should get a match: /^\s*IP/

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[d/l]
[select]

        Try the following:

        use Modern::Perl;

my @RouterOutput = <DATA>;
my $RouterOutput = join ' ', @RouterOutput;

my ( $SwitchName, $SwitchIP ) =
  $RouterOutput =~ /Device\s+ID:\s+([^\s]+).+IP\s+address:\s+([^\s]+)/
+s;

say "$SwitchName\n$SwitchIP";


__DATA__
Device ID: switch1.Core-3750.abc.com
Entry address(es):
  IP address: 10.10.10.10
Platform: cisco WS-C3750G-12S,  Capabilities: Router Switch IGMP
Interface: GigabitEthernet1/0/28,  Port ID (outgoing port): GigabitEth
+ernet2/0/7
Holdtime : 145 sec

Version :
Cisco IOS Software, C3750 Software (C3750-IPSERVICESK9-M), Version 12.
+2(55)SE4, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2011 by Cisco Systems, Inc.
Compiled Tue 06-Sep-11 02:59 by prod_rel_team

advertisement version: 2
Protocol Hello:  OUI=0x00000C, Protocol ID=0x0112; payload len=27, val
+ue=00000000FFFFFFFF01022507000000000000A8B1D400F080FF0000
VTP Management Domain: 'networks'
Native VLAN: 1
Duplex: full

        [download]

        Output:

        switch1.Core-3750.abc.com
10.10.10.10

        [download]
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[d/l]
[select]
Re: Split() first 3 elements of @array
by philiprbrenan (Monk) on Aug 28, 2012 at 18:43 UTC
[reply]
[d/l]
Re: Split() first 3 elements of @array
by pvaldes (Chaplain) on Aug 29, 2012 at 16:40 UTC

    maybe like this, untested

    while (<$RouterOutput>);
if ($. <=3) {
    @Data = split /' '/, $RouterOutput;
    ...
    }

    [download]
[reply]
[d/l]

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