我想验证正在提交的电子邮件是否已经存在于文本文件(php）中

I want to validate if an email being submitting already exist in a text file (php)

代码不工作，请告诉我哪里出错了。我想通过表格获得客户提交的电子邮件，并验证它是否已经存在于特定文件中。

$email = isset($_POST["email"]) ? $_POST["email"] : ""; 
$file = fopen("emails.txt", "r");
$num = 0;
$text[] = 0;
//get lines in file
while (!feof($file)) {
    $text[$num] = fgets($file);
    $num= $num + 1;
    // validate if entry already exist
     if ($email == $text[$num]) {
             echo $email, $text[$num], ",";
    }
}
fclose($file);

您可以使用strpos检查字符串中的电子邮件

//validate if entry already exist
if (strpos($text[$num], $email) !== false) {
     echo $email, $text[$num], ",";
}