Hi Monks,
This is my first posting and I am relatively new to Perl. Hence please excuse if I failed to follow any posting rules.

I have a text file called "top.spef" that has the following lines -

*NAME_MAP

*1 ab
*2 abc
*3 abcd
*4 def
*5 ghi
*6 klm
*7 mno
*8 kji
*9 ips
*10 dlm

*PORTS

*D_NET *2 25
*D_NET *3 16
*D_NET *5 8
*D_NET *9 3
[download]

Here is what I want to do -

1. I want to remove "*" wherever it occurs,

2. I want to store the lines in between "NAME_MAP" and "PORTS" into a hash.

3. I want to replace numbers 2, 3, 5 and 9 in second column in lines that contain "D_NET" with the corresponding values of keys 2, 3, 5 and 9 from hash in step#2 above .

In order to do this, I wrote a small script as below -

#!/usr/bin/perl
  
#use strict;
use warnings;
  
open(IHF, "<", "top.spef");
  
while( <IHF> ) {
       my @keys;
       my ($n, $k1);
       my %nets;
       my @net;
       my $item;
         
       next if (/^\n/);
       s/\*//g;
       s/^\s//g;
       s/\//:/g;
         
 ### Here we store the lines between the lines
 ### NAME_MAP and PORT into a hash called %mapping"
 ### and print the key,value pairs
       if (/NAME_MAP/ .. /PORTS/) {
         next if (/NAME_MAP/);
         next if (/PORTS/);
         %mapping = split;
         @keys = sort keys %mapping;
          
  
         foreach $k1 (sort keys %mapping) {
             print "$k1 = $mapping{$k1}\n";
         }
       }
  
       if (/D_NET/) {
           my @anet = split;
           %nets = ($anet[1] , $anet[0]);
           for $n (sort keys %nets) {
              print "$mapping{$n}\n";
           }
       }
}
[download]

When I execute this code I get the following error -

Use of uninitialized value in concatenation (.) or string at ./mapping
+.pl line 39, <IHF> line 23
[download]

I am assuming this error is issued by Perl because probably the hash %mapping scope may be not visible in the below part of the code -

       if (/D_NET/) {
           my @anet = split;
           %nets = ($anet[1] , $anet[0]);
           for $n (sort keys %nets) {
              print "$mapping{$n}\n";
           }
       }
[download]

Can you kindly suggest me what I am doing wrong and how to fix this problem ?
I very much appreciate all your help in advance.


Best Regards,
Dan

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