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From: @(#)uniq.1 8.1 (Berkeley) 6/6/93
$FreeBSD: src/usr.bin/uniq/uniq.1,v 1.19 2005/01/17 07:44:34 ru Exp $

.Dd July 3, 2004 .Dt UNIQ 1 .Os .Sh NAME .Nm uniq .Nd report or filter out repeated lines in a file .Sh SYNOPSIS .Nm .Op Fl c | Fl d | Fl u .Op Fl i .Op Fl f Ar num .Op Fl s Ar chars .Oo .Ar input_file .Op Ar output_file .Oc .Sh DESCRIPTION The .Nm utility reads the specified .Ar input_file comparing adjacent lines, and writes a copy of each unique input line to the .Ar output_file . If .Ar input_file is a single dash

q Sq Fl or absent, the standard input is read. If .Ar output_file is absent, standard output is used for output. The second and succeeding copies of identical adjacent input lines are not written. Repeated lines in the input will not be detected if they are not adjacent, so it may be necessary to sort the files first.

p The following options are available: l -tag -width Ds t Fl c Precede each output line with the count of the number of times the line occurred in the input, followed by a single space. t Fl d Only output lines that are repeated in the input. t Fl f Ar num Ignore the first .Ar num fields in each input line when doing comparisons. A field is a string of non-blank characters separated from adjacent fields by blanks. Field numbers are one based, i.e., the first field is field one. t Fl s Ar chars Ignore the first .Ar chars characters in each input line when doing comparisons. If specified in conjunction with the .Fl f option, the first .Ar chars characters after the first .Ar num fields will be ignored. Character numbers are one based, i.e., the first character is character one. t Fl u Only output lines that are not repeated in the input. t Fl i Case insensitive comparison of lines. .It Fl Ns Ar n
(Deprecated; replaced by
.Fl f ) .
Ignore the first n
fields on each input line when doing comparisons,
where n is a number.
A field is a string of non-blank
characters separated from adjacent fields
by blanks.
.It Cm \(pl Ns Ar n
(Deprecated; replaced by
.Fl s ) .
Ignore the first
.Ar m
characters when doing comparisons, where
.Ar m
is a
number.
.El .Sh ENVIRONMENT The .Ev LANG , .Ev LC_ALL , .Ev LC_COLLATE and .Ev LC_CTYPE environment variables affect the execution of .Nm as described in .Xr environ 7 . .Sh EXIT STATUS .Ex -std .Sh COMPATIBILITY The historic .Cm \(pl Ns Ar number and .Fl Ns Ar number options have been deprecated but are still supported in this implementation. .Sh SEE ALSO .Xr sort 1 .Sh STANDARDS The .Nm utility conforms to .St -p1003.1-2001 as amended by Cor. 1-2002. .Sh HISTORY A .Nm command appeared in .At v3 .