textbox validation accepting IPs in javascript

Question

I want to have a validation function it must accept 3 types:

var
portvar
ipvar

one of my problems is in IPvar user input must be in this syntax as example:

[192.168.1.0/24,10.1.1.0/24]

how can I accept just such Ips from textboxes?

jerluc · Accepted Answer · 2011-07-05 09:15:35Z

1

You could check it against a regular expression like this:

var textVal = ...;
if ((/^\[(?!,)(,?(?:(?:25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(?:25[0-5]|2[0-4]\d|[01]?\d\d?)\/[1-9]\d*)+\]$/).test(textVal)) {
  alert('Valid!');
}
else {
  alert('Invalid!');
}

The regular expression identifies valid IP's with each part of the IP being a number between 0 and 255. Additionally, as your example shows, each IP must be followed by a single / and then a number representing the subnet mask. Lastly, multiple IPs are separated by commas (however the regular expression does not allow a comma at the very beginning or the very end).

(By the way, the second IP address in your example isn't valid).

edited Jul 5, 2011 at 9:15

answered Jul 5, 2011 at 8:31

jerluc

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6 Comments

Nickool Over a year ago

after / isn't it a subnet mask?

Nickool Over a year ago

if I don't put comma again it will tell valid

Nickool Over a year ago

would you please tell me what are these?(/^[(?!,)

jerluc Over a year ago

/^\[(?!,) means the line must begin with a bracket and should not be immediately followed by a comma.

Nickool Over a year ago

I got it thanks jerluc, can you tell me 25[0-5] means 250 till 255? what is {3}? and the sign =>:

|

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