OptionsOn cat itself
-b
Number the non-blank output lines, starting at 1
-e
Display non-printing characters (see the -v option), and display a dollar sign (‘$’) at the end of each line
-l
Set an exclusive advisory lock on the standard output file descriptor. This lock is set using fcntl(2) with the F_SETLKW command. If the output file is already locked, cat will block until the lock is acquired
-n
Number the output lines, starting at 1
-s
Squeeze multiple adjacent empty lines, causing the output to be single spaced
-t
Display non-printing characters (see the -v option), and display tab characters as ‘^I’
-u
Disable output buffering
-v
Display non-printing characters so they are visible. Control characters print as ‘^X’ for control-X; the delete character (octal 0177) prints as ‘^?’. Non-ASCII characters (with the high bit set) are printed as ‘M-’ (for meta) followed by the character for the low 7 bits
