Form verification email and URL

In this chapter we will introduce how to verify names, e-mails, and URLs.

PHP - Verify name

The following code will detect whether the name field contains letters and spaces in a simple way. If the name field value is illegal, an error message will be output:

$name = test_input($_POST["name"]);
if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
  $nameErr = "只允许字母和空格"; 
}

##preg_match — Perform regular expression matching.

	Syntax: int preg_match ( string $pattern , string $subject [, array $matches [, int $flags ]] ) at Search the subject string for content that matches the regular expression given by pattern. If matches is provided, it will be populated with the results of the search. $matches[0] will contain text that matches the entire pattern, $matches[1] will contain text that matches the first captured subpattern in parentheses, and so on.

Syntax:

int preg_match ( string $pattern , string $subject [, array $matches [, int $flags ]] )

at Search the subject string for content that matches the regular expression given by pattern. If matches is provided, it will be populated with the results of the search. $matches[0] will contain text that matches the entire pattern, $matches[1] will contain text that matches the first captured subpattern in parentheses, and so on.

PHP - Verification Email

The following code will check whether the e-mail address is legitimate in a simple way. If the e-mail address is illegal, an error message will be output:

$email = test_input($_POST["email"]);
if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/",$email)) {
  $emailErr = "非法邮箱格式"; 
}

##PHP - Verify URL

The following code will detect the URL Whether the address is legal (the following regular expression operation URL contains dashes: "-"). If the URL address is illegal, an error message will be output:

$website = test_input($_POST["website"]);
if (!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",$website)) {
  $websiteErr = "非法的 URL 的地址"; 
}

PHP - Verify Name, E-mail, and URL

The code is as follows:

<?php
// 定义变量并默认设置为空值
$nameErr = $emailErr = $genderErr = $websiteErr = "";
$name = $email = $gender = $comment = $website = "";
if ($_SERVER["REQUEST_METHOD"] == "POST") {
   if (empty($_POST["name"])) {
      $nameErr = "Name is required";
      } else {
         $name = test_input($_POST["name"]);
         // 检测名字是否只包含字母跟空格
         if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
         $nameErr = "只允许字母和空格"; 
         }
     }
   
   if (empty($_POST["email"])) {
      $emailErr = "Email is required";
   } else {
      $email = test_input($_POST["email"]);
      // 检测邮箱是否合法
      if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/",$email)) {
         $emailErr = "非法邮箱格式"; 
      }
   }
     
   if (empty($_POST["website"])) {
      $website = "";
   } else {
      $website = test_input($_POST["website"]);
      // 检测 URL 地址是否合法
     if (!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",$website)) {
         $websiteErr = "非法的 URL 的地址"; 
      }
   }
   if (empty($_POST["comment"])) {
      $comment = "";
   } else {
      $comment = test_input($_POST["comment"]);
   }
   if (empty($_POST["gender"])) {
      $genderErr = "性别是必需的";
   } else {
      $gender = test_input($_POST["gender"]);
   }
}
?>

Running example»

Form verification email and URL

PHP - Verify name

The following code will detect the URL Whether the address is legal (the following regular expression operation URL contains dashes: "-"). If the URL address is illegal, an error message will be output:

The code is as follows:

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