Delete lines from file A that is in file B

Question

I have two large files A and B

I need to delete lines that appear in file B from file A and save the result

to file C

I have tried comm -23 file1

Answer 1

As you mentioned, since comm needs sorted file to fetch the diff you can do in-line sorting before using comm like this :

comm -23 <(sort file1) <(sort file2) > fileC