#!/usr/bin/perl -w
use strict;

my %colcnt;
my (@text, @lhs, @rhs);
my $max;
my $maxcnt = 0;

while (<DATA>) {
  chomp;  
  push @text, $_; # save text for later
  my @chars = split //, $_;
  for (my $i = 1; $i < @chars; ++$i) { #skip first char (no pred)
    $colcnt{$i}++ if $chars[$i] ne ' ' && $chars[$i - 1] eq ' '; 
    $colcnt{$i} |= 0; # make sure it is init for warnings
    $max = $i and $maxcnt = $colcnt{$i} if $colcnt{$i} > $maxcnt;
  }
}

foreach (@text) {
  my ($lhs, $rhs) = unpack("A$max A*", $_);
  push @lhs, $lhs;
  push @rhs, $rhs;
}

print "LHS:\n";
print join "\n", @lhs;
print "\n\nRHS:\n";
print join "\n", @rhs;

__DATA__
This script handles      about        how
arbitrary    spacing     much
for column skip as       white    space  is
long as there are        in each column.  I
enough lines of text     can't figure out
and a "normal" dist
of spaces.
                                how      to
It also doesn't make     do it in one pass though.
  any assumpions