http://www.perlmonks.org?node_id=990303


in reply to Split() first 3 elements of @array

Select the first 3 elements of an array as:

 @array[0..2]

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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 $_;
 }

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Produces

1 CCCC BBBB AAAA
2 CCCC BBBB AAAA
3 CCCC BBBB AAAA

Replies are listed 'Best First'.
Re^2: Split() first 3 elements of @array
by hmb104 (Sexton) on Aug 28, 2012 at 19:10 UTC

    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]
[reply]
[d/l]
[select]
      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]
        use Modern::Perl;

use Modern::Perl;

say '  IP address: 10.10.10.10' =~ /IP\s+address:\s+([^\s]+)/;
say 'IP address: 10.10.10.10' =~ /IP\s+address:\s+([^\s]+)/;
say '  IP address: 10.10.10.10' =~ /^\s*IP\s+address:\s+([^\s]+)/;
say 'IP address: 10.10.10.10' =~ /^\s*IP\s+address:\s+([^\s]+)/;

        [download]

        Output:

        10.10.10.10
10.10.10.10
10.10.10.10
10.10.10.10

        [download]

        Update: Ah! hmb104 was referring to using split, not the regex (which isn't attempting to match at the beginning of a line and is fully anchored w/o mentioning the spaces before "IP address:").

[reply]
[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]
[reply]
[d/l]
[select]

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