root@DESKTOP-1N42TVH:/home/test2# ls
a.txt
root@DESKTOP-1N42TVH:/home/test2# cat a.txt
d ees j
x e.s u
z e s u
w e     s u
root@DESKTOP-1N42TVH:/home/test2# grep "e.s" a.txt
d ees j
x e.s u
z e s u
w e     s u
root@DESKTOP-1N42TVH:/home/test2# grep "e[[:punct:]]s" a.txt     ## [[:punct:]]表示标点符号
x e.s u