正则表达式从IPv4八位字节修剪前导零

Question

I am using the following regex in a PHP script to collect IPv4 Addresses and to also perform some validation of the IPv4 addresses.

A txt file of IPs is read into an array with a file() command, then a foreach loop using preg_match and this regex matches the IPv4 addresses.

However, it currently includes any leading zeros before each octet.

Is it possible to improve this regex to trim any leading zeros in each octet without completely discarding IPs with leading zeros? I would prefer to do this in a single regex instead of adding an additional function to clear the leading zeros.

/(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)/

Correct output:

38.10.125.242
38.1.1.24

Incorrect output:

038.010.125.242
038.001.001.024

I have been using Lumadis.be to test, but none of the regexes that I tried from other answers in Stack Overflow seem to work?.

Answer 1

Simpler is just:

preg_replace('/\b0+/', '', $str);

Since we know the only word boundaries are at the . and the start/end of line

Edit: it looks like we need a lookahead to avoid empty octets

preg_replace('/\b0+(?=\d)/', '', $str)