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  my @rows = map { chomp; [ split /;/ ] } <>;
  # now you have an array of arrays (rows of columns)
...
  for ( @rows ) {
    print "@{$_}[ @non_zero_columns ]\n";
  }

  my %zero_columns;
  @zero_columns{ 0 .. $#{$rows[0]} } = (); # initially, all columns mi
+ght have 0.
...
  my @non_zero_columns = grep {
    ! exists $zero_columns{$_}
  } 0 .. $#{$rows[0]};