align_columns.rb

align_column.rb

#!/bin/sh
exec ruby -x "$0" "$@"
#!ruby
# coding: utf-8
#
# align_column.rb
# Copyright (c) 2019 Koichi OKADA. All rights reserved.
# This script is destributed under the MIT license.
#

require 'optparse'
require 'tempfile'
require 'unicode/display_width' # Requires: gem install unicode-display_width

opts = OptionParser.new
opts.banner  = "Usage: #{File.basename $0} [<options>] [<files> ...]\n"
opts.banner += "Options:"
opts.on("-Fpattern", "Pattern for field separator"){|v| $; = Regexp.new v}
opts.parse! ARGV

def Array.zip(a,b); a.length > b.length ? a.zip(b) : b.zip(a); end
class String
  def drop_sgr; self.gsub(/\e\[[0-9;]*m/, ""); end
end

# Determine columns widths
w = [0]
tmp = Tempfile.new(File.basename $0)
while gets
  tmp.print $_
  $_.chomp!
  $F = $_.split

  w1 = $F.map{|s| Unicode::DisplayWidth.of s.drop_sgr}
  w = Array::zip(w, w1).map{|a| a.compact.max}
end
tmp.close

# Align columns
tmp.open
while $_ = tmp.gets
  $_.chomp!
  $F = $_.split

  puts $F.zip(w).map{|f,w|
    pad = " " * [(w||0) - Unicode::DisplayWidth.of(f.drop_sgr), 0].max
    /^[-+]?[0-9]*([.][0-9]+)?$/ =~ f ? pad + f : f + pad
  }.join(" ")
end
tmp.close!