Convert a percent rating to a five star grade

example.txt

   0 .....  
   1 .....  21 X....  41 XX...  61 XXX..  81 XXXX.
   2 .....  22 X....  42 XX...  62 XXX..  82 XXXX.
   3 .....  23 X....  43 XX...  63 XXX..  83 XXXX.
   4 .....  24 X....  44 XX...  64 XXX..  84 XXXX.
   5 /....  25 X/...  45 XX/..  65 XXX/.  85 XXXX/
   6 /....  26 X/...  46 XX/..  66 XXX/.  86 XXXX/
   7 /....  27 X/...  47 XX/..  67 XXX/.  87 XXXX/
   8 /....  28 X/...  48 XX/..  68 XXX/.  88 XXXX/
   9 /....  29 X/...  49 XX/..  69 XXX/.  89 XXXX/
  10 /....  30 X/...  50 XX/..  70 XXX/.  90 XXXX/
  11 /....  31 X/...  51 XX/..  71 XXX/.  91 XXXX/
  12 /....  32 X/...  52 XX/..  72 XXX/.  92 XXXX/
  13 /....  33 X/...  53 XX/..  73 XXX/.  93 XXXX/
  14 /....  34 X/...  54 XX/..  74 XXX/.  94 XXXX/
  15 X....  35 XX...  55 XXX..  75 XXXX.  95 XXXXX
  16 X....  36 XX...  56 XXX..  76 XXXX.  96 XXXXX
  17 X....  37 XX...  57 XXX..  77 XXXX.  97 XXXXX
  18 X....  38 XX...  58 XXX..  78 XXXX.  98 XXXXX
  19 X....  39 XX...  59 XXX..  79 XXXX.  99 XXXXX
  20 X....  40 XX...  60 XXX..  80 XXXX. 100 XXXXX

percent_to_stars.php

<?php
function percent_to_stars($p, $star, $half, $empty)
{
  $stars   = floor((round($p / 10) / 2));
  $halves  = round($p / 10) % 2;
  $empties = 5 - $stars - $halves;
  return str_repeat($star, $stars)
       . str_repeat($half, $halves)
       . str_repeat($empty, $empties);
}

percent_to_stars.rb

def percent_to_stars(p, star="X", half="/", empty=".")
  stars = ((p / 10.0).round / 2).floor
  halves = (p / 10.0) % 2
  return star * stars
       + half * halves
       + empty * (5 - stars - halves)
end