XML file creation in Perl

Question

My input file is

TBLA      COLA      A    B    
TBLA      COLB      D    E    
TBLB      COLX      M    N     
TBLB      COLD      A    B   
TBLC      COLD          


        

Answer 1

Given the very simple data structure, It seems a bit unneccessary to use a whole XML writer. However, I'll assume that that the table and column names are valid XML tag names.

Here is a simple script that reads through the data without storing it in an intermediary data structure. It works with perl5 v10 and better.

use strict; use warnings; use feature 'say';

my $last_table;
say '';
while(<>) {
  chomp;
  my ($table, $col, $old, $new) = split /\t/;
  s/&/&/g, s/";
  } elsif ($last_table ne $table) {
    say "  ";
    say "  <$table>";
  }
  $last_table = $table;
  say "    <$col>";
  say "      $old";
  say "      $new";
  say "    ";
}
say "   if defined $last_table;
say '';