.\" Copyright (c) 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" This code is derived from software contributed to Berkeley by .\" the Institute of Electrical and Electronics Engineers, Inc. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" 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 .Pq 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. .Pp The following options are available: .Bl -tag -width Ds .It 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. .It Fl d Only output lines that are repeated in the input. .It 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. .It 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. .It Fl u Only output lines that are not repeated in the input. .It 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 .