NAME

comm − select or reject lines common to two sorted files

SYNOPSIS

comm [ − [ 123 ] ] file1 file2

DESCRIPTION

Comm reads file1 and file2, which should be ordered in ASCII collating sequence (see sort(1)), and produces a three-column output: lines only in file1; lines only in file2; and lines in both files. The file name − means the standard input. 

Flags 1, 2, or 3 suppress printing of the corresponding column.  Thus comm −12 prints only the lines common to the two files; comm −23 prints only lines in the first file but not in the second; comm −123 is a no-op. 

EXAMPLE

comm -12 filea fileb

prints only the lines common to filea and fileb. 

comm -23 filea fileb

prints only lines in the first file but not in the second. 

comm -123 filea fileb

is not an option, as it suppresses all output. 

comm -3 filea fileb

prints only the lines that differ in the two files. 

SEE ALSO

cmp(1), diff(1), sort(1), uniq(1). 

Version 2.3  —  July 04, 1985