1.\" Copyright (c) 1989, 1990 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)comm.1 6.4 (Berkeley) 07/24/90 7.\" 8.Dd 9.Os BSD 4.4 10.Dt COMM 1 11.Sh NAME 12.Nm comm 13.Nd select or reject lines common to two files 14.Sh SYNOPSIS 15.Nm comm 16.Op Fl 123 17.Ar file1 file2 18.Sh DESCRIPTION 19The 20.Nm comm 21utility reads 22.Ar file1 23and 24.Ar file2 , 25which should be 26sorted lexically, and produces three text 27columns as output: lines only in 28.Ar file1 ; 29lines only in 30.Ar file2 ; 31and lines in both files. 32.Pp 33The filename 34.Sq Fl 35means the standard input. 36.Pp 37The following options are available: 38.Tw Ds 39.Tp Fl 1 40Suppress printing of column 1. 41.Tp Fl 2 42Suppress printing of column 2. 43.Tp Fl 3 44Suppress printing of column 3. 45.Tp 46.Pp 47Each column will have a number of tab characters prepended to it 48equal to the number of lower numbered columns that are being printed. 49For example, if column number two is being suppressed, lines printed 50in column number one will not have any tabs preceding them, and lines 51printed in column number three will have one. 52.Pp 53.Nm Comm 54assumes that the files are lexically sorted; all characters 55participate in line comparisons. 56.Pp 57.Nm Comm 58exits 0 on success, >0 if an error occurred. 59.Sh SEE ALSO 60.Xr cmp 1 , 61.Xr diff 1 , 62.Xr sort 1 , 63.Xr uniq 1 64.Sh STANDARDS 65The 66.Nm comm 67function is expected to be POSIX 1003.2 compatible. 68