shell的正则匹配IP

[root@master~]#cattest.txt
2014-08-17
20140907
140322
aa.aa.bb.cc
af.23.67.90
ffffff
oo.09.0f.87.90
192.168.1.2
121.168.2.3
0987238349
999.999.99.999
123-212-2-3

用grep

[root@master~]#egrep"((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)"test.txt
192.168.1.2
121.168.2.3