How to get complementary lines from two text files?
File file1.txt has
123 foo
234 bar
...
File file2.txt has
123 foo
333 foobar
234 bar
...
I want to get all lines in file1.txt and not in file2.txt. The two files are hundreds of MB large and contain non-ASCII characters. What’s a fast way to do this?
Lines, specifically?