whois.com.php

<?php

# demo
var_dump(isComDomainAvailable('aaaa.com'));
var_dump(isComDomainAvailable('askdhbfjasdfbh.com'));

# job
foreach (getDomainName() as $domainName) {
	if (isComDomainAvailable($domainName)) {
		echo $domainName.PHP_EOL;
	}
}

function isComDomainAvailable(string $domainName): bool {
	$fp = fsockopen('whois.crsnic.net', 43);
	if (!$fp) {
		echo $domainName." - Connection error!\n";
		return false;
	}

	fputs($fp, "$domainName\r\n");

	$string = '';

	while (!feof($fp)) {
		$string .= fgets($fp, 128);
	}
	fclose($fp);
	if (stripos($string, 'No match for ') !== false) {
		return true;
	}

	return false;
}

function getDomainName() {
	$filename = './domain.list.txt';
	$domainArray = file_exists($filename)?file($filename, FILE_SKIP_EMPTY_LINES | FILE_IGNORE_NEW_LINES):[];
	foreach ($domainArray as $domainName) {
		yield $domainName;
	}
}