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 6.6 (Berkeley) 06/17/91 7.\" 8.Dd 9.Os 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 ``-'' means the standard input. 34.Pp 35The following options are available: 36.Bl -tag -width Ds 37.It Fl 1 38Suppress printing of column 1. 39.It Fl 2 40Suppress printing of column 2. 41.It Fl 3 42Suppress printing of column 3. 43.El 44.Pp 45Each column will have a number of tab characters prepended to it 46equal to the number of lower numbered columns that are being printed. 47For example, if column number two is being suppressed, lines printed 48in column number one will not have any tabs preceding them, and lines 49printed in column number three will have one. 50.Pp 51.Nm Comm 52assumes that the files are lexically sorted; all characters 53participate in line comparisons. 54.Pp 55.Nm Comm 56exits 0 on success, >0 if an error occurred. 57.Sh SEE ALSO 58.Xr cmp 1 , 59.Xr diff 1 , 60.Xr sort 1 , 61.Xr uniq 1 62.Sh STANDARDS 63The 64.Nm comm 65command is expected to be POSIX 1003.2 compatible. 66