$re = '/<div\s*class="menu-menu-1-container">(.*?)<\/div>/s';
$str = '
<!DOCTYPE html>
<!--[if IE 7]>
<html class="ie ie7" lang="en-US">
<![endif]-->
<!--[if IE 8]>
<html class="ie ie8" lang="en-US">
<![endif]-->
<!--[if !(IE 7) & !(IE 8)]><!-->
<html lang="en-US">
<!--<![endif]-->
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width">
<title>test</title>
<link rel="profile" href="http://gmpg.org/xfn/11">
<link rel="pingback" href="http://localhost/wp/xmlrpc.php">
<!--[if lt IE 9]>
<script src="http://localhost/wp/wp-content/themes/twentythirteen/js/html5.js"></script>
<![endif]-->
<link rel="alternate" type="application/rss+xml" title="test » Feed"
href="http://localhost/wp/feed/" />
<link rel="alternate" type="application/rss+xml" title="test » Comments Feed"
href="http://localhost/wp/comments/feed/" />
<script type="text/javascript">
window._wpemojiSettings = {"baseUrl":"http:\\/\\/s.w.org\\/images\\/core\\/emoji
\\/72x72\\/","ext":".png","source":{"concatemoji":"http:\\/\\/localhost\\/wp\\/wp-includes\\/js\\/wp-emoji-
release.min.js?ver=4.3.1"}};
!function(a,b,c){function d(a){var c=b.createElement
("canvas"),d=c.getContext&&c.getContext("2d");return d&&d.fillText?(d.textBaseline="top",d.font="600
32px Arial","flag"===a?(d.fillText(String.fromCharCode(55356,56812,55356,56807),0,0),c.toDataURL
().length>3e3):(d.fillText(String.fromCharCode(55357,56835),0,0),0!==d.getImageData(16,16,1,1).data
[0])):!1}function e(a){var c=b.createElement
("script");c.src=a,c.type="text/javascript",b.getElementsByTagName("head")[0].appendChild(c)}var
f,g;c.supports={simple:d("simple"),flag:d("flag")},c.DOMReady=!1,c.readyCallback=function()
{c.DOMReady=!0},c.supports.simple&&c.supports.flag||(g=function(){c.readyCallback
()},b.addEventListener?(b.addEventListener("DOMContentLoaded",g,!1),a.addEventListener("load",g,!1)):
(a.attachEvent("onload",g),b.attachEvent("onreadystatechange",function()
{"complete"===b.readyState&&c.readyCallback()})),f=c.source||{},f.concatemoji?e
(f.concatemoji):f.wpemoji&&f.twemoji&&(e(f.twemoji),e(f.wpemoji)))}
(window,document,window._wpemojiSettings);
</script>
<style type="text/css">
img.wp-smiley,
img.emoji {
display: inline !important;
border: none !important;
box-shadow: none !important;
height: 1em !important;
width: 1em !important;
margin: 0 .07em !important;
vertical-align: -0.1em !important;
background: none !important;
padding: 0 !important;
}
</style>
<link rel=\'stylesheet\' id=\'twentythirteen-fonts-css\' href=\'https://fonts.googleapis.com/css?
family=Source+Sans+Pro%3A300%2C400%2C700%2C300italic%2C400italic%2C700italic%7CBitter
%3A400%2C700&subset=latin%2Clatin-ext\' type=\'text/css\' media=\'all\' />
<link rel=\'stylesheet\' id=\'genericons-css\' href=\'http://localhost/wp/wp-
content/themes/twentythirteen/genericons/genericons.css?ver=3.03\' type=\'text/css\' media=\'all\' />
<link rel=\'stylesheet\' id=\'twentythirteen-style-css\' href=\'http://localhost/wp/wp-
content/themes/twentythirteen/style.css?ver=2013-07-18\' type=\'text/css\' media=\'all\' />
<!--[if lt IE 9]>
<link rel=\'stylesheet\' id=\'twentythirteen-ie-css\' href=\'http://localhost/wp/wp-
content/themes/twentythirteen/css/ie.css?ver=2013-07-18\' type=\'text/css\' media=\'all\' />
<![endif]-->
<script type=\'text/javascript\' src=\'http://localhost/wp/wp-includes/js/jquery/jquery.js?
ver=1.11.3\'></script>
<script type=\'text/javascript\' src=\'http://localhost/wp/wp-includes/js/jquery/jquery-migrate.min.js?
ver=1.2.1\'></script>
<link rel="EditURI" type="application/rsd+xml" title="RSD" href="http://localhost/wp/xmlrpc.php?rsd"
/>
<link rel="wlwmanifest" type="application/wlwmanifest+xml" href="http://localhost/wp/wp-
includes/wlwmanifest.xml" />
<meta name="generator" content="WordPress 4.3.1" />
<style type="text/css">.recentcomments a{display:inline !important;padding:0 !
important;margin:0 !important;}</style>
<style type="text/css" id="twentythirteen-header-css">
.site-header {
background: url(http://localhost/wp/wp-
content/themes/twentythirteen/images/headers/circle.png) no-repeat scroll top;
background-size: 1600px auto;
}
@media (max-width: 767px) {
.site-header {
background-size: 768px auto;
}
}
@media (max-width: 359px) {
.site-header {
background-size: 360px auto;
}
}
</style>
</head>
<body class="single-author">
<div id="page" class="hfeed site">
<header id="masthead" class="site-header" role="banner">
<a class="home-link" href="http://localhost/wp/" title="test" rel="home">
<h1 class="site-title">test</h1>
<h2 class="site-description">Just another WordPress site</h2>
</a>
<div id="navbar" class="navbar">
<nav id="site-navigation" class="navigation main-navigation"
role="navigation">
<button class="menu-toggle">Menu</button>
<a class="screen-reader-text skip-link" href="#content"
title="Skip to content">Skip to content</a>
<div class="menu-menu-1-container"><ul id="primary-menu"
class="nav-menu"><li id="menu-item-35" class="menu-item menu-item-type-custom menu-item-object-custom
menu-item-35"><a href="http://gooogle.com">chekc</a></li>
<li id="menu-item-32" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-has-
children menu-item-32"><a href="http://localhost/wp/sample-page/">Sample Page</a>
<ul class="sub-menu">
<li id="menu-item-33" class="menu-item menu-item-type-post_type menu-item-object-post menu-
item-has-children menu-item-33"><a href="http://localhost/wp/2015/09/21/hello-world/">test heloo</a>
<ul class="sub-menu">
<li id="menu-item-34" class="menu-item menu-item-type-post_type menu-item-object-post
menu-item-34"><a href="http://localhost/wp/2015/09/24/testkj/">testkj</a></li>
</ul>
</li>
</ul>
</li>
<li id="menu-item-39" class="menu-item menu-item-type-taxonomy menu-item-object-category menu-item-
39"><a href="http://localhost/wp/category/uncategorized/">Uncategorized</a></li>
<li id="menu-item-40" class="menu-item menu-item-type-taxonomy menu-item-object-category menu-item-
40"><a href="http://localhost/wp/category/test/">testttt</a></li>
</ul></div> <form role="search" method="get" class="search-form"
action="http://localhost/wp/">
<label>
<span class="screen-reader-text">Search for:</span>
<input type="search" class="search-field" placeholder="Search
…" value="" name="s" title="Search for:" />
</label>
<input type="submit" class="search-submit" value="Search" />
</form> </nav><!-- #site-navigation -->
</div><!-- #navbar -->
</header><!-- #masthead -->
<div id="main" class="site-main">
';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php