safe tmp paths including keeping extname

safe_tmp_path.rb

# requires the zaru gem, just get it :)

require 'tmpdir'
require 'zaru'

def tmp_path(name_hint = nil)
  name_hint ||= 'tmp'
  extname = File.extname name_hint
  name_hint = Zaru.sanitize! File.basename(name_hint, extname).to_s.gsub(/\s+/, '_')
  path = Dir::Tmpname.create(name_hint) {}
  "#{path}#{extname}"
end

puts tmp_path('foo')
puts tmp_path('foo.csv')

# $ ruby foo.rb
# /var/folders/y5/qt_wf5l52jd12gzd8dxfqpt40000gp/T/foo20141111-57832-vmjgjk
# /var/folders/y5/qt_wf5l52jd12gzd8dxfqpt40000gp/T/foo20141111-57832-1f7t8xa.csv

I'm going to leave this for a future optimization because the Dir::Tmpname doesn't offer the free tempfile cleanup feature