[root@QD1_Master shell_scripts]# grep '123' *

x:123fdafdsa

[root@QD1_Master shell_scripts]# grep -r '123' *

a/z:123

x:123fdafdsa

[root@QD1_Master shell_scripts]# ls

a  x  y

[root@QD1_Master shell_scripts]# grep -nr '123' *

a/z:2:123

x:1:123fdafdsa