NAME :
tac – tac is a Linux command that allows you to see a file line-by-line backwards. It is named by analogy with cat.
SYNOPSIS
tac [OPTION]… [FILE]…
DESCRIPTION
Write each FILE to standard output, last line first. With no FILE, or
when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options
too.
-b, –before
attach the separator before instead of after
-r, –regex
interpret the separator as a regular expression
-s, –separator=STRING
use STRING as the separator instead of newline
–help display this help and exit
–version
output version information and exit