comm
TLDR
Compare two sorted files
$ comm [file1] [file2]
Show lines unique to first file$ comm -23 [file1] [file2]
Show lines unique to second file$ comm -13 [file1] [file2]
Show lines common to both$ comm -12 [file1] [file2]
Compare with custom delimiter$ comm --output-delimiter='|' [file1] [file2]
Compare unsorted files$ comm <(sort [file1]) <(sort [file2])
SYNOPSIS
comm [option]... file1 file2
DESCRIPTION
comm compares two sorted files line by line. Produces three columns: lines unique to file1, lines unique to file2, and lines common to both. Part of GNU coreutils.
PARAMETERS
-1
Suppress column 1 (lines unique to file1)-2
Suppress column 2 (lines unique to file2)-3
Suppress column 3 (common lines)--check-order
Check input is properly sorted--nocheck-order
Skip sort order verification--output-delimiter str
Separate columns with string--total
Output summary counts-z, --zero-terminated
Line delimiter is NUL--help
Display help--version
Show version
OUTPUT COLUMNS
$ unique_to_file1
unique_to_file2
common_to_both
unique_to_file2
common_to_both
CAVEATS
Input files must be sorted. Use process substitution for unsorted files: comm <(sort f1) <(sort f2). Comparisons follow LC_COLLATE rules.
