# File lib/active_support/core_ext/file/atomic.rb, line 20 def atomic_write(file_name, temp_dir = Dir.tmpdir) temp_file = Tempfile.new(basename(file_name), temp_dir) yield temp_file temp_file.close begin # Get original file permissions old_stat = stat(file_name) rescue Errno::ENOENT # No old permissions, write a temp file to determine the defaults check_name = ".permissions_check.#{Thread.current.object_id}.#{Process.pid}.#{rand(1000000)}" open(check_name, "w") { } old_stat = stat(check_name) unlink(check_name) end # Overwrite original file with temp file rename(temp_file.path, file_name) # Set correct permissions on new file chown(old_stat.uid, old_stat.gid, file_name) chmod(old_stat.mode, file_name) end