emacs-mime: base64

 
 4.7 base64
 ==========
 
 Base64 is an encoding that encodes three bytes into four characters,
 thereby increasing the size by about 33%.  The alphabet used for
 encoding is very resistant to mangling during transit.
 
    The following functions are defined by this library:
 
 ‘base64-encode-region’
      base64 encode the selected region.  Return the length of the
      encoded text.  Optional third argument NO-LINE-BREAK means do not
      break long lines into shorter lines.
 
 ‘base64-encode-string’
      base64 encode a string and return the result.
 
 ‘base64-decode-region’
      base64 decode the selected region.  Return the length of the
      decoded text.  If the region can’t be decoded, return ‘nil’ and
      don’t modify the buffer.
 
 ‘base64-decode-string’
      base64 decode a string and return the result.  If the string can’t
      be decoded, ‘nil’ is returned.