tac - concatenate and print files in reverse

SYNOPSIS

       tac  [-br]  [-s separator] [--before] [--regex] [--separa-
       tor=separator] [--help] [--version] [file...]

DESCRIPTION

       This manual page documents the GNU version  of  tac.   tac
       copies  each given file, or the standard input if none are
       given or when a file name of `-' is  encountered,  to  the
       standard  output  with  the order of the records reversed.
       The records are separated by instances of a string,  or  a
       newline  if  none  is  given.   By  default, the separator
       string is attached to the end of the record that  it  fol-
       lows in the file.

   OPTIONS
       -b, --before
              The  separator  is attached to the beginning of the
              record that it precedes in the file.

       -r, --regex
              The separator is a regular expression.

       -s string, --separator=string
              Use string as the record separator.

       --help Print a usage message and exit with a  status  code
              indicating success.

       --version
              Print  version  information on standard output then
              exit.