require 'tempfile' # Write to a file atomically. Useful for situations where you don't # want other processes or threads to see half-written files. # # File.atomic_write("important.file") do |file| # file.write("hello") # end # # If your temp directory is not on the same filesystem as the file you're # trying to write, you can provide a different temporary directory. # # File.atomic_write("/data/something.important", "/data/tmp") do |f| # file.write("hello") # end def File.atomic_write(file_name, temp_dir = Dir.tmpdir) temp_file = Tempfile.new(File.basename(file_name), temp_dir) yield temp_file temp_file.close File.rename(temp_file.path, file_name) end