grep取缩写|awk两个文件取交集

#!/bin/sh

les species_latinName_abbr.txt|grep -E 'Aptenodytes|Gavia|Phoenicopterus|Chlamydotis|Phaethon' | awk '{printf $1","}'

##APTFO,CHLUN,GAVST,PHALE,PHORU

cat a.txt | awk '{a[i]=1;END{getline i < "b.txt";b[i]=1;if(!(i in a)){if(i in b){print $0}}}}'

##