.TH TAC 1
.SH NAME
tac \- concatenate and print files in reverse
.SH SYNOPSIS
.B tac
[\-br] [\-s separator] [\-\-before] [\-\-regex] [\-\-separator=separator]
[file...]
.SH DESCRIPTION
This manual page
documents the GNU version of
.BR tac .
.B 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 follows
in the file.
.SS OPTIONS
.TP
.I "\-b, \-\-before"
The separator is attached to the beginning of the record that it
precedes in the file.
.TP
.I "\-r, \-\-regex"
The separator is a regular expression.
.TP
.I "\-s, \-\-separator separator"
Use
.I separator
as the record separator.
.PP
The long-named options can be introduced with `+' as well as `\-\-',
for compatibility with previous releases.  Eventually support for `+'
will be removed, because it is incompatible with the POSIX.2 standard.