use strict;

my @cols_to_print = qw(LAST_NAME FIRST_NAME);
my @col_nbrs;
while (<DATA>) {
  my $line = $_;
  if ($. == 1) { #1st line of input?
    my @col_names = split(/\s+/, $line);
    for my $x (0..$#cols_to_print) {
      for my $y (0..$#col_names) {
        if ($cols_to_print[$x] eq $col_names[$y]) {
          push @col_nbrs, $y;
          last;
        }
      }
    }
  } else {
    my @cols = split /\s+/, $line;
    @cols = @cols[@col_nbrs]; #slice into wanted column nbrs
    print "@cols\n";
  }
}
__DATA__
CUST_ID FIRST_NAME LAST_NAME FAV_LANG
1 Larry Wall Perl
2 Bill Joy Java
3 Richard Stallman emacslisp
4 Bill Gates tinyBasic
##</code><code>##

Wall Larry
Joy Bill
Stallman Richard
Gates Bill