diff求两个文件的差集

sourceIP.txt中有，resultIP.txt中没有的数据

sourceIP.txt

acb
dd
111
ccc
222
333
444
555
666
777

resultIP.txt

111
222
333
000

求差集

$ diff <(grep "" sourceIP.txt) <(grep "" resultIP.txt) | grep "< *"| awk -F "< " '{print $2}'
acb
dd
444
555
666
777