#!/usr/bin/perl
use warnings;
use strict;

my %fhs; # hash with last_column values

open my $INPUT, '<', 'input_file' or die $!;

while (my $line = <$INPUT>) {
#chomp; # this gives me syntax errors???
my @columns = $line =~ m/\s*(-?[.\d]+)/g; # split columns
  
  foreach ($columns[$#columns]) { # foreach element of the last column = cluster ID

  open my $FORM, '>', 'output.FORM' or die $!;
  my $columnform = "%10s"x(@columns) . "\n";
  # printf ($FORM $columnform, @columns); # hangs, creates empty file

  printf $columnform, @columns; # prints on screen correctly
  close $FORM;
  }
}

##</code><code>##

#!/usr/bin/perl
use warnings;
use strict;

my %fhs; # hash with last_column values

open my $INPUT, '<', 'input_file' or die $!;

while (my $line = <$INPUT>) {
#chomp; # this gives me syntax errors???
my @columns = $line =~ m/\s*(-?[.\d]+)/g; # split columns
  
open my $FORM, '>', 'output.FORM' or die $!;
my $columnform = "%10s"x(@columns) . "\n";
# printf ($FORM $columnform, @columns); # hangs, creates empty file

printf $columnform, @columns; # prints on screen correctly
close $FORM;

  foreach ($columns[$#columns]) { # foreach element of the last column = cluster ID
  # blah
  }
}