OT: PERL Question

Nov 13, 2015 5 Replies

Rate this thread:

Jim Thompson 10 years ago

What is the most compact way to express this IP range with a PERL regular expression:

114.108.128.0 - 114.108.191.255

Thanks! ...Jim Thompson

formatting link

| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Vote

Cydrome Leader 10 years ago

here's an ugly one (they all are) from an IP range regex generator

^114\.108\.(1(2[8-9]|[3-8][0-9]|9[0-1]))\.([0-9]|[1-9][0-9]|1([0-9][0-9])|2([0-4][0-9]|5[0-5]))$

Vote

Jim Thompson 10 years ago

Yup. That's what I was coming up with... ugly ;-) ...Jim Thompson

Vote

Clifford Heath 10 years ago

Convert it to 32-bit binary and test the top 18 bits (discard 14):

use Net::IP; my $ip = new Net::IP("114.108.128.0"); print $ip->binip(), "\n";

=> 01110010011011001000000000000000

Clifford Heath.

Vote

Jasen Betts 10 years ago

as as CIDR range 114.108.129.0/19 but I guess you can't use that.

as regex, assuming input is four-part ip-addresses only.

114\.108\.1(2[89]|[3-8]\d|9[01])\.\d+

\_(?)_

Vote

Martin Brown 10 years ago

Since in the context it will be used you don't mind if it catches malformed IP addresses as well you could swap \d for "." saving 2.

114\.108\.1(2[89]|[3-8].\9[01])\..+

I prefer yours though which is exact on IP addresses. (but he did ask for the shortest regex)

Regards, Martin Brown

Vote

Join the Discussion

Have something to add? Share your thoughts — no account required.

Ask the community — no account required