使用数字范围PHP搜索strpos（）

Question

I want to search a rule, iptables, within a string that has a port blocked—and I want to show that port.

For example, the rule iptables -A OUTPUT -p tcp --dport 8080 -j DROP; I'd like to be able to search by strpos the string tcp --dport 8080 -j DROP but with a range of numbers 1-65335 instead of 8080.

Please excuse my poor English.

Answer 1

Assuming each string is in fixed format like your example, you can search for the number then check if within range using preg_match() function

$str = 'iptables -A OUTPUT -p tcp --dport 8080 -j DROP;';

preg_match('/\d+/', $str, $match); // search for matches
if ($match[0] >= 1 && $match[0] <= 65335) {
    echo "Valid number found on string";
}

Pattern /\d+/ searches for any digit, 1 to unlimited times

Notes:
1. Will cause undefined errors/warnings when no number found on string
2. May become inaccurate when more than 1 whole number found