.TH COMM 1 
.CT 1 files
.SH NAME
comm \- select or reject lines common to two sorted files
.SH SYNOPSIS
.B comm
[
.B -123
]
.I file1 file2
.SH DESCRIPTION
.I Comm
reads
.I file1
and
.IR file2 ,
which are in lexicographical order,
and produces a three column output: lines only in
.IR file1 ;
lines only in
.IR file2 ;
and lines in both files.
The file name
.L -
means the standard input.
.PP
Flag
.LR 1 ,
.LR 2 ,
or
.LR 3
suppresses printing of the corresponding
column.
.SH EXAMPLE
.TP
.EX
comm -12 file1 file2
.EE
.IP
Print lines common to two sorted files.
.SH SOURCE
.B /sys/src/cmd/comm.c
.SH "SEE ALSO"
.IR sort (1),
.IR cmp (1), 
.IR diff (1), 
.IR uniq (1)