or download this
#!/usr/bin/perl
...
2017-12-08 07:01:39 127.0.0.1 GET /course-detail.aspx id=66&catColor=0
+ 443 - 192.168.4.3 (e.g., IP) <server version etc. strings> 200 0 0 5
+30
#Note that I only want to grep IP addresses (192.168.1.1-3) that are i
+n the same netmask specified in $matcher