difference between the content of two files

Question

I have two files one file subset of other and i want to obtain a file which has contents not common to both.for example

File1

apple
         


        

Answer 1

use awk, no sorting necessary (reduce overheads)

$ awk 'FNR==NR{f[$1];next}(!($1 in f)) ' file2 file
mango
orange
jackfruit
grapes
okra