filter a file with other file in bash

bash, linux, sh, shell, solaris

Solution

Is

grep -f file2 -v -F -x file1

sufficient?

NOTE1: Please specify in question, if the actual question is that, you need it to be time/memory optimized.

NOTE2: Get rid of any blank lines in file2.

Problem

i Have a file with numbers, for example: ``` $cat file 31038467 32048169 33058564 34088662 35093964 31018168 31138061 31208369 31538163 31798862 ``` and other for example with ``` $cat file2 31208369 33058564 34088662 31538163 31038467 ``` Then i need other file with lines that are in the first file but not in the second ``` cat $output 35093964 31018168 31138061 31798862 32048169 ``` My real file has 12'000.0000 of lines. Then how can i do it?

Original source