[unix-history] / usr / src / local / tac / tac.1

.\"	@(#)tac.1	1.3 %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).
If no input
.I file
is given, or if the argument `-'
is encountered,
.I tac
reads from the standard input.  Note that in this case
.I tac
stores the entire standard input in a temporary
file before it outputs anything, so for large input it is slow.
.SH EXAMPLES
.RS
tac '-\e
.br
From\ ' /var/mail/$USER
.RE
prints out one's mail messages, most recent first.
.PP
.RS
tac file
.RE
prints the file in reverse, line by line, and:
.PP
.RS
tac /var/log/messages | egrep 'hp.*hard'
.RE
prints out the hard errors on MASSBUS disk drives, most recent first.
.SH SEE ALSO
cat(1), rev(1), tail(1), tmail(1)
.SH BUGS
.I Tac
doesn't handle multiple argument files exactly right, and it's
also unclear in which order they should be processed.
.br
If invoked as `tac < file', 
.I tac
uses a temp file but it doesn't have to.
Commit	Line	Data
2899ecfc	1	.\" @(#)tac.1 1.3 %G%
b4d9d38e JL	2	.\"
	3	.TH TAC 1 ""
	4	.SH NAME
	5	tac \- concatenate and print files in reverse
	6	.SH SYNOPSIS
	7	.B tac
	8	[
	9	.B \-string
	10	] [
	11	.B +string
ffcf70e9	12	] [ file ... ]
b4d9d38e JL	13	.SH DESCRIPTION
	14	.I Tac
	15	reads each
	16	.I file
	17	in sequence
	18	and writes it on the standard output, reversed by the file segments
	19	delimited by
	20	.I string.
	21	.I \-string
	22	specifies segments bounded on the left by
	23	.I string,
	24	while
	25	.I +string
	26	specifies right-bounded segments.
	27	The default is
	28	.I +\en
	29	(print lines in reverse order).
ffcf70e9 JL	30	If no input
	31	.I file
	32	is given, or if the argument `-'
	33	is encountered,
	34	.I tac
	35	reads from the standard input. Note that in this case
	36	.I tac
	37	stores the entire standard input in a temporary
	38	file before it outputs anything, so for large input it is slow.
b4d9d38e JL	39	.SH EXAMPLES
	40	.RS
	41	tac '-\e
	42	.br
2899ecfc	43	From\ ' /var/mail/$USER
b4d9d38e JL	44	.RE
	45	prints out one's mail messages, most recent first.
	46	.PP
	47	.RS
	48	tac file
	49	.RE
	50	prints the file in reverse, line by line, and:
	51	.PP
	52	.RS
2899ecfc	53	tac /var/log/messages \| egrep 'hp.*hard'
b4d9d38e	54	.RE
ffcf70e9	55	prints out the hard errors on MASSBUS disk drives, most recent first.
b4d9d38e JL	56	.SH SEE ALSO
	57	cat(1), rev(1), tail(1), tmail(1)
	58	.SH BUGS
	59	.I Tac
ffcf70e9 JL	60	doesn't handle multiple argument files exactly right, and it's
ffcf70e9 JL	61	also unclear in which order they should be processed.
b4d9d38e	62	.br
ffcf70e9 JL	63	If invoked as `tac < file',
	64	.I tac
	65	uses a temp file but it doesn't have to.