cat [-aenotuvV] [filename ...]
-a      same as -u if input begins with BOM
-e      add '$' at the end of line
-n      add line number
-o      suppress buffering for output
-t      show tab character as '^I'
-u      unicode text processing
-v      show control characters as '^' + alphabet, except tab and newline.
-V      show version
--      declare end of options