
cat [option] [filename] [EOF for exit]

 <option>   <filename>  <eof>   <job>
            readme.txt          Read all texts or binaries in 'readme.txt' file
 -c         readme.txt          Create 'readme.txt' file
 -w         readme.txt  QUIT    Create and write text in 'readme.txt' then exit by 'QUIT' word
 -a         readme.txt  QUIT    Write into 'readme.txt' then close the file by 'QUIT' word
