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#29085

PHP

PHP good email validator

function validEmail($email)
{
   $isValid = true;
   $atIndex = strrpos($email, "@");
   if (is_bool($atIndex) && !$atIndex)
   {
      $isValid = false;
   }
   else
   {
      $domain = substr($email, $atIndex+1);
      $local = substr($email, 0, $atIndex);
      $localLen = strlen($local);
      $domainLen = strlen($domain);
      if ($localLen < 1 || $localLen > 64)
      {
         // local part length exceeded
         $isValid = false;
      }
      else if ($domainLen < 1 || $domainLen > 255)
      {
         // domain part length exceeded
         $isValid = false;
      }
      else if ($local[0] == '.' || $local[$localLen-1] == '.')
      {
         // local part starts or ends with '.'
         $isValid = false;
      }
      else if (preg_match('/\\.\\./', $local))
      {
         // local part has two consecutive dots
         $isValid = false;
      }
      else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain))
      {
         // character not valid in domain part
         $isValid = false;
      }
      else if (preg_match('/\\.\\./', $domain))
      {
         // domain part has two consecutive dots
         $isValid = false;
      }
      else if
(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/',
                 str_replace("\\\\","",$local)))
      {
         // character not valid in local part unless 
         // local part is quoted
         if (!preg_match('/^"(\\\\"|[^"])+"$/',
             str_replace("\\\\","",$local)))
         {
            $isValid = false;
         }
      }
      if ($isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain,"A")))
      {
         // domain not found in DNS
         $isValid = false;
      }
   }
   return $isValid;
}
https://snipt.net/embed/8a75a7543435b2d4646096175e9f8482/
https://snipt.net/raw/8a75a7543435b2d4646096175e9f8482/
8a75a7543435b2d4646096175e9f8482
php
PHP
64
2014-04-19T00:32:36
True
False
/api/public/snipt/29085/
php-good-email-validator
<table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><a href="#L-1"> 1</a> <a href="#L-2"> 2</a> <a href="#L-3"> 3</a> <a href="#L-4"> 4</a> <a href="#L-5"> 5</a> <a href="#L-6"> 6</a> <a href="#L-7"> 7</a> <a href="#L-8"> 8</a> <a href="#L-9"> 9</a> <a href="#L-10">10</a> <a href="#L-11">11</a> <a href="#L-12">12</a> <a href="#L-13">13</a> <a href="#L-14">14</a> <a href="#L-15">15</a> <a href="#L-16">16</a> <a href="#L-17">17</a> <a href="#L-18">18</a> <a href="#L-19">19</a> <a href="#L-20">20</a> <a href="#L-21">21</a> <a href="#L-22">22</a> <a href="#L-23">23</a> <a href="#L-24">24</a> <a href="#L-25">25</a> <a href="#L-26">26</a> <a href="#L-27">27</a> <a href="#L-28">28</a> <a href="#L-29">29</a> <a href="#L-30">30</a> <a href="#L-31">31</a> <a href="#L-32">32</a> <a href="#L-33">33</a> <a href="#L-34">34</a> <a href="#L-35">35</a> <a href="#L-36">36</a> <a href="#L-37">37</a> <a href="#L-38">38</a> <a href="#L-39">39</a> <a href="#L-40">40</a> <a href="#L-41">41</a> <a href="#L-42">42</a> <a href="#L-43">43</a> <a href="#L-44">44</a> <a href="#L-45">45</a> <a href="#L-46">46</a> <a href="#L-47">47</a> <a href="#L-48">48</a> <a href="#L-49">49</a> <a href="#L-50">50</a> <a href="#L-51">51</a> <a href="#L-52">52</a> <a href="#L-53">53</a> <a href="#L-54">54</a> <a href="#L-55">55</a> <a href="#L-56">56</a> <a href="#L-57">57</a> <a href="#L-58">58</a> <a href="#L-59">59</a> <a href="#L-60">60</a> <a href="#L-61">61</a> <a href="#L-62">62</a> <a href="#L-63">63</a> <a href="#L-64">64</a></pre></div></td><td class="code"><div class="highlight"><pre><span id="L-1"><a name="L-1"></a><span class="x">function validEmail($email)</span> </span><span id="L-2"><a name="L-2"></a><span class="x">{</span> </span><span id="L-3"><a name="L-3"></a><span class="x"> $isValid = true;</span> </span><span id="L-4"><a name="L-4"></a><span class="x"> $atIndex = strrpos($email, &quot;@&quot;);</span> </span><span id="L-5"><a name="L-5"></a><span class="x"> if (is_bool($atIndex) &amp;&amp; !$atIndex)</span> </span><span id="L-6"><a name="L-6"></a><span class="x"> {</span> </span><span id="L-7"><a name="L-7"></a><span class="x"> $isValid = false;</span> </span><span id="L-8"><a name="L-8"></a><span class="x"> }</span> </span><span id="L-9"><a name="L-9"></a><span class="x"> else</span> </span><span id="L-10"><a name="L-10"></a><span class="x"> {</span> </span><span id="L-11"><a name="L-11"></a><span class="x"> $domain = substr($email, $atIndex+1);</span> </span><span id="L-12"><a name="L-12"></a><span class="x"> $local = substr($email, 0, $atIndex);</span> </span><span id="L-13"><a name="L-13"></a><span class="x"> $localLen = strlen($local);</span> </span><span id="L-14"><a name="L-14"></a><span class="x"> $domainLen = strlen($domain);</span> </span><span id="L-15"><a name="L-15"></a><span class="x"> if ($localLen &lt; 1 || $localLen &gt; 64)</span> </span><span id="L-16"><a name="L-16"></a><span class="x"> {</span> </span><span id="L-17"><a name="L-17"></a><span class="x"> // local part length exceeded</span> </span><span id="L-18"><a name="L-18"></a><span class="x"> $isValid = false;</span> </span><span id="L-19"><a name="L-19"></a><span class="x"> }</span> </span><span id="L-20"><a name="L-20"></a><span class="x"> else if ($domainLen &lt; 1 || $domainLen &gt; 255)</span> </span><span id="L-21"><a name="L-21"></a><span class="x"> {</span> </span><span id="L-22"><a name="L-22"></a><span class="x"> // domain part length exceeded</span> </span><span id="L-23"><a name="L-23"></a><span class="x"> $isValid = false;</span> </span><span id="L-24"><a name="L-24"></a><span class="x"> }</span> </span><span id="L-25"><a name="L-25"></a><span class="x"> else if ($local[0] == &#39;.&#39; || $local[$localLen-1] == &#39;.&#39;)</span> </span><span id="L-26"><a name="L-26"></a><span class="x"> {</span> </span><span id="L-27"><a name="L-27"></a><span class="x"> // local part starts or ends with &#39;.&#39;</span> </span><span id="L-28"><a name="L-28"></a><span class="x"> $isValid = false;</span> </span><span id="L-29"><a name="L-29"></a><span class="x"> }</span> </span><span id="L-30"><a name="L-30"></a><span class="x"> else if (preg_match(&#39;/\\.\\./&#39;, $local))</span> </span><span id="L-31"><a name="L-31"></a><span class="x"> {</span> </span><span id="L-32"><a name="L-32"></a><span class="x"> // local part has two consecutive dots</span> </span><span id="L-33"><a name="L-33"></a><span class="x"> $isValid = false;</span> </span><span id="L-34"><a name="L-34"></a><span class="x"> }</span> </span><span id="L-35"><a name="L-35"></a><span class="x"> else if (!preg_match(&#39;/^[A-Za-z0-9\\-\\.]+$/&#39;, $domain))</span> </span><span id="L-36"><a name="L-36"></a><span class="x"> {</span> </span><span id="L-37"><a name="L-37"></a><span class="x"> // character not valid in domain part</span> </span><span id="L-38"><a name="L-38"></a><span class="x"> $isValid = false;</span> </span><span id="L-39"><a name="L-39"></a><span class="x"> }</span> </span><span id="L-40"><a name="L-40"></a><span class="x"> else if (preg_match(&#39;/\\.\\./&#39;, $domain))</span> </span><span id="L-41"><a name="L-41"></a><span class="x"> {</span> </span><span id="L-42"><a name="L-42"></a><span class="x"> // domain part has two consecutive dots</span> </span><span id="L-43"><a name="L-43"></a><span class="x"> $isValid = false;</span> </span><span id="L-44"><a name="L-44"></a><span class="x"> }</span> </span><span id="L-45"><a name="L-45"></a><span class="x"> else if</span> </span><span id="L-46"><a name="L-46"></a><span class="x">(!preg_match(&#39;/^(\\\\.|[A-Za-z0-9!#%&amp;`_=\\/$\&#39;*+?^{}|~.-])+$/&#39;,</span> </span><span id="L-47"><a name="L-47"></a><span class="x"> str_replace(&quot;\\\\&quot;,&quot;&quot;,$local)))</span> </span><span id="L-48"><a name="L-48"></a><span class="x"> {</span> </span><span id="L-49"><a name="L-49"></a><span class="x"> // character not valid in local part unless </span> </span><span id="L-50"><a name="L-50"></a><span class="x"> // local part is quoted</span> </span><span id="L-51"><a name="L-51"></a><span class="x"> if (!preg_match(&#39;/^&quot;(\\\\&quot;|[^&quot;])+&quot;$/&#39;,</span> </span><span id="L-52"><a name="L-52"></a><span class="x"> str_replace(&quot;\\\\&quot;,&quot;&quot;,$local)))</span> </span><span id="L-53"><a name="L-53"></a><span class="x"> {</span> </span><span id="L-54"><a name="L-54"></a><span class="x"> $isValid = false;</span> </span><span id="L-55"><a name="L-55"></a><span class="x"> }</span> </span><span id="L-56"><a name="L-56"></a><span class="x"> }</span> </span><span id="L-57"><a name="L-57"></a><span class="x"> if ($isValid &amp;&amp; !(checkdnsrr($domain,&quot;MX&quot;) || checkdnsrr($domain,&quot;A&quot;)))</span> </span><span id="L-58"><a name="L-58"></a><span class="x"> {</span> </span><span id="L-59"><a name="L-59"></a><span class="x"> // domain not found in DNS</span> </span><span id="L-60"><a name="L-60"></a><span class="x"> $isValid = false;</span> </span><span id="L-61"><a name="L-61"></a><span class="x"> }</span> </span><span id="L-62"><a name="L-62"></a><span class="x"> }</span> </span><span id="L-63"><a name="L-63"></a><span class="x"> return $isValid;</span> </span><span id="L-64"><a name="L-64"></a><span class="x">}</span> </span></pre></div> </td></tr></table>
email, php