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 6.3 (Berkeley) 06/11/90 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 ``-'' means the standard input. 34.Pp 35The following options are available: 36.Tp Fl 1 37Suppress printing of column 1. 38.Tp Fl 2 39Suppress printing of column 2. 40.Tp Fl 3 41Suppress printing of column 3. 42.Tp 43.Pp 44Each column will have a number of tab characters prepended to it 45equal to the number of lower numbered columns that are being printed. 46For example, if column number two is being suppressed, lines printed 47in column number one will not have any tabs preceding them, and lines 48printed in column number three will have one. 49.Pp 50.Nm Comm 51assumes that the files are lexically sorted; all characters 52participate in line comparisons. 53.Pp 54.Nm Comm 55exits 0 on success, >0 if an error occurred. 56.Sh SEE ALSO 57.Xr cmp 1 , 58.Xr diff 1 , 59.Xr sort 1 , 60.Xr uniq 1 61.Sh STANDARDS 62The 63.Nm comm 64function is expected to be POSIX 1003.2 compatible. 65