#!/usr/bin/perl
# By: Ben Okopnik <ben@okopnik.com>, 07:45 2012-07-16
# Finds nearest "tape measure" fraction for a given decimal
use warnings;
use strict;

die "Usage: ", $0 =~ /([^\/]+)$/, " <number> [tolerance]\n"
    unless @ARGV && $ARGV[0] =~ /^(\d+)?(\.\d+)$/;  # Yep, positives only :)
my $int = $1 || 0;
my $dec = $2;
die "No mantissa\n" unless $dec > 0;
die "Not a reasonable tolerance\n"
    if $ARGV[1] && $ARGV[1] !~ /^0?\.\d+$/;

my $tolerance = $ARGV[1] || .001;        # 1 mil is the default 
my $denom = 2;
{
    for my $num (1 .. $denom - 1){
        die $int + $dec, " is equal to $int $num/$denom (+/-$tolerance)\n"
            if abs($dec - $num / $denom) <= $tolerance;
    }
    $denom *= 2;
    redo;
}