usr/src/local/tac/tac.1

.\"     @(#)tac.1       1.1 %G%
.\"
.TH TAC 1 ""
.SH NAME
tac \- concatenate and print files in reverse
.SH SYNOPSIS
.B tac
[
.B \-string
] [
.B +string
] file ...
.SH DESCRIPTION
.I Tac
reads each
.I file
in sequence
and writes it on the standard output, reversed by the file segments
delimited by
.I string.
.I \-string
specifies segments bounded on the left by
.I string,
while
.I +string
specifies right-bounded segments.
The default is
.I +\en
(print lines in reverse order).
.SH EXAMPLES
.RS
tac '-\e
.br
From\ ' /usr/spool/mail/$USER
.RE
prints out one's mail messages, most recent first.
.PP
.RS
tac file
.RE
prints the file in reverse, line by line, and:
.PP
.RS
tac file1 file2 >file3
.RE
reverses each of the first two files by line and places the
concatenated result on the third.
.SH SEE ALSO
cat(1), rev(1), tail(1), tmail(1)
.SH BUGS
.I Tac
doesn't yet handle multiple argument files exactly right.  It's
also unclear which direction it should process them in.
.br
.I Tac
does not (and cannot efficiently) work on piped input.