Formats Tab-separated text so that it aligns to columns with a fixed width font, retains tabs

Tabulater

#!/usr/bin/ruby

class Array
	def transpose
		width  = self.map {|e| e.length}.max
		trans  = []
		(0..width - 1).each do |col|
			self.each do |row|
				element = row[col]
				(trans[col] ||= []) << element
			end
		end
		trans
	end
end

class NilClass
	def length
		0
	end
end

rows = $<.read.split(/\n/).map {|line| line.split /\t/}

columns = rows.transpose

lengths = columns.map {|c| c.map{|e| e.length}.max }

padded_columns = (0 .. columns.length - 1).to_a.map do |index|
	width = lengths[index]
	columns[index].map do |element|
		(element || "") + (" " * ((width) - element.length))
	end
end

padded_columns.transpose.each do |row|
	puts row.join("\t")
end