gistfile1.rb

#!/usr/bin/env ruby
file = STDIN.read[/lessc: ([^*]+\.less)/, 1] || ENV["TM_FILEPATH"]

outname = File.dirname(file) + "/" + File.basename(file, File.extname(file)) + ".css"

output = IO.popen("lessc \"#{file}\" 2>&1", "w+") do |pipe|
  pipe.close_write
  pipe.read
end

if $? != 0
  puts output.gsub(/\[\d\d?m/, '')
else
  puts "success"
  File.open(outname, "w") { |f| f.write output }
end