Usage: /usr/bin/comm [OPTION]... FILE1 FILE2
Compare sorted files FILE1 and FILE2 line by line.

When FILE1 or FILE2 is -, read standard input.

With no options, produce three-column output.  Column one contains
lines unique to FILE1, column two contains lines unique to FILE2,
and column three contains lines common to both files.
  -1     suppress column 1 (lines unique to FILE1)
  -2     suppress column 2 (lines unique to FILE2)
  -3     suppress column 3 (lines that appear in both files)
      --check-order
         check that the input is correctly sorted,
         even if all input lines are pairable
      --nocheck-order
         do not check that the input is correctly sorted
      --output-delimiter=STR
         separate columns with STR
      --total
         output a summary
  -z, --zero-terminated
         line delimiter is NUL, not newline
      --help
         display this help and exit
      --version
         output version information and exit

Comparisons honor the rules specified by 'LC_COLLATE'.

Examples:
  /usr/bin/comm -12 file1 file2  Print only lines present in both file1 and file2.
  /usr/bin/comm -3 file1 file2  Print lines in file1 not in file2, and vice versa.

Report bugs to: <bug-coreutils@gnu.org>.
GNU coreutils home page: <https://www.gnu.org/software/coreutils/>
General help using GNU software: <https://www.gnu.org/gethelp/>
Full documentation <https://www.gnu.org/software/coreutils/comm>
or available locally via: info '(coreutils) comm invocation'