Regular expression range question (was: Clueless newbie - help!)

[odosbucket]

I know zip about perl, but am modifying a script to generate some statistics. I'm trying to modify an if statement to include a range of ip addresses - the statement starts out looking like this:

if ($ip =~ /123\.45\.678\.<p>

How do I put in a range of numbers for the last segment of the ip address? The range needs to be 1-126 for one set and 17-31 for another. Nothing I've tried works, and my brief digging around on the web hasn't revealed an answer. Help?!? Thanks!

Edit kudra, 2002-05-07 Changed title; added code tags

[maverick]

Checking to see if an ip address is within a certain range is doable with a regexp....but I don't think that's the best way to handle it as the regexp quickly becomes really nasty.

Rather, check out a module called Net::IP::Match. From it's description it seems to do exactly what you need.

HTH

/\/\averick
OmG! They killed tilly! You *bleep*!!

[runrig]

Don't Use A Regex!
See the Socket module and inet_aton(). Or alternatively there are some net address range modules, e.g. Array::IntSpan::IP and Net::CIDR::Lite...

------------
ooo  O\O  ooo tilly was here :,(

[Anonymous Monk]

Thanks to Amel and all of you for the suggestions! It works now. Thank you thank you!!! --odosbucket

[JayBonci]

A really general regexp that you might use looks like this:

my $txt = "169.254.0.210";

if($txt =~ /\d{1,3}\.\d{1,3}\.\d{1,3}\.(\d{1,3})/ and ($1 < 250 && $1
> 220))
{
  print "VALID ADDRESS!\n";
}

You might notice the pattern in the regexp that looks like \d{1,3}\. which means "match any number at least one time, and no more than three times and then a dot". This is a very general IP pattern. The above code also matches the last set (via the parenthases), and then compares it in the other half of the if statement.

To apply it to your specific example:

if($ip =~ /123\.45\.678\.(\d{1,3})/ and ($1 < 1 and $1 > 126))
#code here

If you are SURE of the first three octects of your IP address, this will work just fine for you. Hope this helps.

    --jb

Update In response to Amel's posting, yes, you'd have to test it for IP validity (and I wouldn't use it to match a whole IP in reality), but it matches the general pattern, and will work simply if all you need to test is the last octect. Zero is a valid IP digit if not in the first or last octect.

[dsb]

This is more like a very general 3-digit match regex. Your regex will match numbers from 256 to 999 as well, which are outside of the valid IP range(0-255). Even 0 and 255 should not be used since those are reserved IP addresses.

---



Amel
This is my cool %SIG

[dsb]

Um, if I'm clear, you need to know how to match a number from 1-126 or from 17-31:

# tests for a 3 digit number from 1 - 126
$num =~ m/^(1(?:[01]\d|2[0-6])|\d?\d)$/; 

# tests for a 2 digit number from 17 - 31
$num =~ m/^(1[7-9]|2\d|3[01])$/;

This is a bit messy so you may want to investigate methods by which you can check IP's that don't use a regex. Perhaps one of the Net modules.

---



Amel
This is my cool %SIG