What have you tried? The following may be what you want:

use strict;
use warnings;

my $lastIP;

while (<DATA>) {
  print if /network name|interface name|VRID|state|primary address/i;
  print "$lastIP\n\n" if /Monitored circuits:/ and defined $lastIP;
  $lastIP = $1 if /((\d{1,3}\.){3}\d{1,3})/;
}
[download]

Prints:

Network name A
        VRID 145
        State:        Master    
        Primary address:    194.551.205.250
135.51.045.242

    VRID 145
        State:        backup    
        Primary address:    19.51.205.20
135.51.05.22
[download]

Hello

Thank you.

What if there are Multiple network names and multiple interface names; we want to get for EACH network name, there will be multiple interfaces...

The network is name A
fgdfgdg
interface 1a       
VRID 145
        State:        Master    
        Primary address:    194.551.25.253
135.51.045.242
Monitored circuits:
             (priority 150), IBM_A (priority 150)
    VRID 145
        State:        backup    
        Primary address:    19.51.205.20
135.51.05.22

interface B1        
VRID 145
        State:        Master    
        Primary address:    194.551.205.250
135.51.045.242

    VRID 145
        State:        backup    
        Primary address:    19.51.205.20
135.51.05.22

The network is name B
fgdfgdg
interface edsf_B       
VRID 145
        State:        Master    
        Primary address:    194.551.205.250
135.51.045.242

    VRID 145
        State:        backup    
        Primary address:    19.51.205.20
135.51.05.22

interface Bd1       
VRID 145
        State:        Master    
        Primary address:    194.551.205.250
135.51.045.242

    VRID 145
        State:        backup    
        Primary address:    19.51.205.20
135.51.05.22
.
.
.
The network is name BGT_ds
fgdfgdg
interface e_B       
VRID 145
dfsdfsdf
sdfsdf        State:        Master    
        Primary address:    194.551.205.250
135.51.045.242
sdfsdfsdf
    VRID 145
        dfsdfsdfState:        backup    
        Primary address:    19.51.205.20
135.51.05.22
sdfsdf
interface Bd1       
VRID 145  sdfsdfsdf
        State:        Master    
        Primary address:    194.551.205.250
135.51.045.242
sdfsdf
    VRID 145
      sdfsdf  State:        backup    
        Primary address:    19.51.205.20
135.51.05.22
[download]

Perhaps if I explain how the code works you can adapt it to your actual data? Here's the main part of code again:

my $lastIP;

while (<DATA>) {
  print if /network name|interface name|VRID|state|primary address/i;
  print "$lastIP\n\n" if /Monitored circuits:/ and defined $lastIP;
  $lastIP = $1 if /((\d{1,3}\.){3}\d{1,3})/;
}
[download]

$lastIP remembers the last IP address seen so it can be printed when "Monitored circuits" is noticed.

while (<DATA>) reads the data one line at a time. You would normally use a file handled that you had created with open inFile, '<', 'filename' in place of DATA.

print without parameters prints the contents of the default variable - in this case the data line that was last read from DATA. if /network name|i...address/i matches an interesting line (insensitive to case) and allows the print if there is a match.

print "$lastIP\n\n" prints the IP address preceeding the line containing "Monitored circuits".

This most important line is the one that matches "interesting lines". It does that by matching any of "network name", "interface name", "VRID", "state" or "primary address". Note the | between each string in the regular experssion pattern. They allow a match on any of the strings in the pattern.

You should be able to take that and extend the match to do what you require. If not, show us your attempt, what it prints, and what you would like it to print. Note that we only need pertinant data and only enough to demonstrate the problem. Otherwise the problem gets burried in clutter. Reduce your data to a bare minimum the shows the issue.

---

DWIM is Perl's answer to Gödel

$/=undef;
$d=<DATA>;
my (@ip)=($d=~m/number addresses(?:.*?)((?:\d{1,3}\.){3}\d{1,3})/gsi);

print "Other addresses: ". join("\n",@ip)."\n";

__DATA__
Network name A
Interface WEB_A
    ggggggggg
        VRID 145
    State:        Master
                   XXXXXXXXXXXX
    Effective  Priority:    200
    07:09:56:04:0t:ef
        Primary address:    194.551.205.250
        Number addresses:    1
        135.51.045.242
Monitored circuits:
            vbgghdfgdfg
Interface WEB_B
    ggggggggg
    Agggggg
    VRID 145
    State:        backup
                   XXXXXXXXXXXX
    Effective  Priority:    200
    07:09:56:04:0t:ef
        Primary address:    19.51.205.20
        Next advertisement:    0
        Number addresses:    1
            135.51.05.22
        Monitored circuits:
            vbgghdfgdfg
[download]

It appears from the example that the 'Network name' is a header, and are multiple 'Interface records', but it's not clear whether there could be multiple Network Name/Interface groups per file? The following assumes not.

It would also appear that could be more than one "address above Monitored circuit.", going by the "Number of addresses" field. I don't think either of the other solutions would cater for that? If so, this might be useful. I've also captured and output the Number of IPs value, but that is easily removed or discarded.

You'll note that this makes no attempt to verify the format or legality of the ip addresses whilst parsing the file, simply treating them as whitespace delimited tokens. If you need to verify the addresses, that is better done as a separate step.

#! perl -slw
use strict;

my( $nName, $iName, $vrid, $state, $paddr, $nAddr, $oAddrs, @oAddrs );

die "File does not contain a Network name header"
    unless ( $nName ) = <DATA> =~ m[Network\sname \s+ (\S+)]x;

local $/ = "\nI";
while( <DATA> ) {
    if(
        ( $iName, $vrid, $state, $paddr, $nAddr, $oAddrs ) = m[
            (?=.*? nterface           \s+ (\S+) )
            (?=.*? VRID               \s+ (\S+) )
            (?=.*? State:             \s+ (\S+) )
            (?=.*? Primary\saddress:  \s+ (\S+) )
            (?=.*?
                Number\saddresses:    \s+ (\S+)
                ( .+? )
                (?=Monitored\scircuits:)
            )
        ]smx
    ) {
        @oAddrs = split ' ', $oAddrs;
        print join ', ', $nName, $iName, $vrid, $state, $paddr, $nAddr
+, @oAddrs;
    }
    else {
        warn "File did not match required format";
    }
}
[download]

Output

C:\test>junk1
A, WEB_A, 145, Master, 194.551.205.250, 1, 135.51.045.242
A, WEB_B, 145, backup, 19.51.205.20, 2, 135.51.05.22, 321.654.987.111
A, WEB_C, 145, backup, 19.51.205.20, 3, 135.51.05.22, 123.456.789.001,
+ 321.654.987.111
[download]

Extended dataset

Hi

when there is multiple network the code does print each of the network name ?

Any clues ?

Maybe you missed the bit where I said

but it's not clear whether there could be multiple Network Name/Interface groups per file? The following assumes not.

If there are multiple 'Network name'/'Interface name' groups in each file, then you could adapt my solution with an extra outer loop, but you would probably be better to use one of the other solutions.

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.