#!/usr/bin/perl
# tab_compress.pl - Don Yang (uguu.org)
#
# Convert consecutive spaces to tabs, assuming tab stops at 8 spaces.
#
# 09/09/12

use strict;

while( my $line = <> )
{
   $line =~ s/\s*$//s;

   # Convert line to tab groups
   my @pieces = ();
   while( $line =~ s/^(.{8})(.*)$/$2/ )
   {
      push @pieces, $1;
   }
   if( $line ne "" )
   {
      push @pieces, $line;
   }

   # Output pieces
   foreach my $p (@pieces)
   {
      $p =~ s/\s+$/\t/;
      print $p;
   }

   # End of current line
   print "\n";
}