Removing common lines between two files

To remove common lines between two files you can use grep, comm or join command.

grep only works for small files. Use -v along with -f.

grep -vf file2 file1

This displays lines from file1 that do not match any line in file2.

comm is a utility command that works on lexically sorted files. It takes two files as input and produces three text columns as output: lines only in the first file; lines only in the second file; and lines in both files. You can suppress printing of any column by using -1, -2 or -3 option accordingly.

comm -1 -3 file2 file1

This displays lines from file1 that do not match any line in file2.

Finally, there is join, a utility command that performs an equality join on the specified files. Its -v option also allows to remove common lines between two files.

join -v1 -v2 file1 file2