1.\" Copyright (c) 1989, 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the Institute of Electrical and Electronics Engineers, Inc. 6.\" 7.\" %sccs.include.redist.man% 8.\" 9.\" @(#)comm.1 8.1 (Berkeley) 06/06/93 10.\" 11.Dd 12.Os 13.Dt COMM 1 14.Sh NAME 15.Nm comm 16.Nd select or reject lines common to two files 17.Sh SYNOPSIS 18.Nm comm 19.Op Fl 123 20.Ar file1 file2 21.Sh DESCRIPTION 22The 23.Nm comm 24utility reads 25.Ar file1 26and 27.Ar file2 , 28which should be 29sorted lexically, and produces three text 30columns as output: lines only in 31.Ar file1 ; 32lines only in 33.Ar file2 ; 34and lines in both files. 35.Pp 36The filename ``-'' means the standard input. 37.Pp 38The following options are available: 39.Bl -tag -width Ds 40.It Fl 1 41Suppress printing of column 1. 42.It Fl 2 43Suppress printing of column 2. 44.It Fl 3 45Suppress printing of column 3. 46.El 47.Pp 48Each column will have a number of tab characters prepended to it 49equal to the number of lower numbered columns that are being printed. 50For example, if column number two is being suppressed, lines printed 51in column number one will not have any tabs preceding them, and lines 52printed in column number three will have one. 53.Pp 54.Nm Comm 55assumes that the files are lexically sorted; all characters 56participate in line comparisons. 57.Pp 58.Nm Comm 59exits 0 on success, >0 if an error occurred. 60.Sh SEE ALSO 61.Xr cmp 1 , 62.Xr diff 1 , 63.Xr sort 1 , 64.Xr uniq 1 65.Sh STANDARDS 66The 67.Nm comm 68command is expected to be POSIX 1003.2 compatible. 69