If you can load the entire file into memory, the following will split the file into records: 
my @records = split(/^(?=I)/m, $file);

[download]

The just extract the REFDES and modify the PKG_TYPE 

my %pkg_lkup (
   ... => ...,
   ... => ...,
   ... => ...,
);

for my $rec (@records) {
   if ( my ($refdes) = $rec =~ /REFDES=(.*)/ ) {
      if (exists($pkg_lkup{$refdes})) {
         $rec =~ s/PKG_TYPE=.*/PKG_TYPE=$pkg_lkup{$refdes}/;
      }
   }
   print($rec);
}

[download]

In Perl 5.10, the substitution can be written more efficiently as 

$rec =~ s/PKG_TYPE=\K.*/$pkg_lkup{$refdes}/;

[download]

In reply to Re: Modify a line following a target line? by ikegami
in thread Modify a line following a target line? by djincnj

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