compare two sorted files line by line

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

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
      --help     display this help and exit
      --version  output version information and exit

Note, comparisons honour the rules specified by `LC_COLLATE'.

  comm -12 file1 file2  Print only lines present in both file1 and file2.
  comm -3  file1 file2  Print lines in file1 not in file2, and vice versa.

Report comm bugs to
GNU coreutils home page: <>
General help using GNU software: <>
For complete documentation, run: info coreutils 'comm invocation'