CODEWITHSUNDEEP
regex
user1896290
user1896290

Reputation: 94

Regex numeric range with no leading zeros

I am trying to validate this pattern:

1.1.1.1 up to 254.254.254.254, but with no leading zeros. so 001.001.001.001 should not match.

I have 

/^([01]?[0-9]?[0-9]|2[0-4][0-9]|25[0-4])\.([01]?[0-9]?[0-9]|2[0-4][0-9]|25[0-4])\.([01]?[0-9]?[0-9]|2[0-4][0-9]|25[0-4])\.([01]?[0-9]?[0-9]|2[0-4][0-9]|25[0-4])$/

but this matches the leading zeros. Can anyone recommend how to fix this?

Upvotes: 0

Views: 1476

Answers (4)

Templum Iovis
Templum Iovis

Reputation: 67

Try This.

([1-9]$|[1-9][0-9]$|[12][0-9][0-9]$)\.([0-9]$|[1-9][0-9]$|[12][0-9][0-9]$)\.([0-9]$|[1-9][0-9]$|[12][0-9][0-9]$)\.([1-9]$|[1-9][0-9]$|[12][0-9][0-9]$)

Upvotes: 0

paddy
paddy

Reputation: 63471

Each element will be:

[1-9][0-9]?|1[0-9][0-9]|2[0-4][0-9]|25[0-4]

Breakdown of parts:

(1-99)      (100-199)   (200-249)   (250-254)

Oh, and one other thing I should mention... You need to handle the number 0 in the 2nd, 3rd and 4rd places. So just put an extra option for a single 0 digit in those groups. I don't think it's valid to have a zero as the first number in an IP address (although it is valid if it's a mask).

Upvotes: 3

Placido
Placido

Reputation: 1385

This should work

^(([1-9][0-9]?|1[0-9]{2}|2[0-4][0-9]|25[0-4]))\.(?1)\.(?1)\.(?1)$

Upvotes: 0

sapi
sapi

Reputation: 10224

For repeating patterns like this, it's handy to use numbered repetition. The following should match what you're after

([1-9]\d{0,3}\.){3}[1-9]\d{0,3}

EDIT: I'm asleep and missed the part to cap at .254. I'll update when I get a chance.

Upvotes: 0

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