M-x describe-current-coding-system

Coding system for saving this buffer:
  u -- mule-utf-8-unix

Default coding system (for new files):
  u -- mule-utf-8 (alias: utf-8)

Coding system for keyboard input:
  u -- utf-8 (alias of mule-utf-8)

Coding system for terminal output:
  u -- utf-8 (alias of mule-utf-8)

Defaults for subprocess I/O:
  decoding: u -- mule-utf-8 (alias: utf-8)

  encoding: u -- mule-utf-8 (alias: utf-8)