blocks|key|1624097|text|您的两个示例需要两种不同的技术才能可靠。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1624098|示例1只需要strpos()|offset|length|style|CODE|1624099|if+(strpos($subjectString,+$searchString)+!==+FALSE)+{
++//+substring+exists
}+else+{
++//+substring+doesn't+exist
}|code-block|syntax|javascript|1624100|如果要以不区分大小写的方式进行匹配，则可以使用stripos()。|1624101|例如，两种情况下，最好使用数组。这是因为如果数组中有strpos()，那么11.22.22.11方法将与11.22.22.110匹配--而您不希望这样做。|1624102|相反，您可以这样做，使用in_array()|1624103|//+Get+a+list+of+IPs+from+file+and+split+into+an+array
$ips+=+preg_split('/\s%2B/',+trim(file_get_contents('list-of-ips.txt')));

if+(in_array($searchIP,+$ips))+{
++//+IP+exists
}+else+{
++//+IP+doesn't+exist
}|1624104|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/function.strpos.php|1|http://php.net/manual/en/function.in-array.php^0|0|6|8|6|8|0|0|0|N|9|0|Q|8|11|B|1G|C|0|C|A|C|A|1|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|15|8|@$D|16|E|17|F|G]]|9|@$D|18|E|19|1|1A]]|A|$]]|$1|H|3|I|5|J|7|1B|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|1C|8|@$D|1D|E|1E|F|G]]|9|@]|A|$]]|$1|O|3|P|5|6|7|1F|8|@$D|1G|E|1H|F|G]|$D|1I|E|1J|F|G]|$D|1K|E|1L|F|G]]|9|@]|A|$]]|$1|Q|3|R|5|6|7|1M|8|@$D|1N|E|1O|F|G]]|9|@$D|1P|E|1Q|1|1R]]|A|$]]|$1|S|3|T|5|J|7|1S|8|@]|9|@]|A|$K|L]]|$1|U|3|-4|5|6|7|1T|8|@]|9|@]|A|$]]]|V|$W|$5|X|Y|Z|A|$10|11]]|12|$5|X|Y|Z|A|$10|13]]]]

Your two examples would require two different techniques to be reliable.

Example 1 simply requires <a href="http://php.net/manual/en/function.strpos.php" rel="nofollow"><code>strpos()</code></a>:

<pre><code>if (strpos($subjectString, $searchString) !== FALSE) {
 // substring exists
} else {
 // substring doesn't exist
}
</code></pre>

You could use <code>stripos()</code> instead if you want to match in a case-insensitive manner.

For example two it would be better to use an array. This is because the <code>strpos()</code> approach would match <code>11.22.22.11</code> if <code>11.22.22.110</code> was in the array - and you don't want this.

Instead, you would do something like this, using <a href="http://php.net/manual/en/function.in-array.php" rel="nofollow"><code>in_array()</code></a>:

<pre><code>// Get a list of IPs from file and split into an array
$ips = preg_split('/\s+/', trim(file_get_contents('list-of-ips.txt')));

if (in_array($searchIP, $ips)) {
 // IP exists
} else {
 // IP doesn't exist
}
</code></pre>

blocks|key|1624009|text|if(strpos($file_contents,+"119.92.11")+!==+false)
{
++//do+your+stuff
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1624010|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>if(strpos($file_contents, "119.92.11") !== false)
{
 //do your stuff
}
</code></pre>

blocks|key|1594443|text|这是用于外部文件的|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1594444|$ips+=+file+(+$file+);
$searchIP+=+"119.92.11";
$found+=+false;
foreach+(+$ips+as+$ip+)+{
++++if+($ip+==+$searchIP)+{
++++++++$found+=+true;
++++}
}

if+($found)+{
++++echo+$searchIP,+"+Found";
}|code-block|syntax|javascript|1594445|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is for external file 

<pre><code>$ips = file ( $file );
$searchIP = "119.92.11";
$found = false;
foreach ( $ips as $ip ) {
 if ($ip == $searchIP) {
 $found = true;
 }
}

if ($found) {
 echo $searchIP, " Found";
}
</code></pre>

blocks|key|1624060|text|只需使用strpos函数即可。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1624061|1624062|函数的strpos()函数返回字符串在另一个字符串中第一个出现的位置。|blockquote|1624063|1624064|如果找不到字符串，则此函数返回FALSE。|1624065|1624066|例如：|1624067|$ipAddresses+=+'//+IP+Blocklist
118.92.00
119.92.11
125.23.10';

if+(strpos($ipAddresses,"119.92.11")+!=+FALSE)+{
++++//+IP+ADDRESS+WAS+FOUND
}+else+{
++++//+IP+ADDRESS+NOT+FOUND
}|code-block|syntax|javascript|1624068|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|T|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|U|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|V|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|X|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|Y|8|@]|9|@]|A|$]]|$1|L|3|M|5|N|7|Z|8|@]|9|@]|A|$O|P]]|$1|Q|3|-4|5|6|7|10|8|@]|9|@]|A|$]]]|R|$]]

Just use the strpos function.

<blockquote>
 The strpos() function returns the position of the first occurrence of
 a string inside another string.
 
 If the string is not found, this function returns FALSE.
</blockquote>

For example:

<pre><code>$ipAddresses = '// IP Blocklist
118.92.00
119.92.11
125.23.10';

if (strpos($ipAddresses,"119.92.11") != FALSE) {
 // IP ADDRESS WAS FOUND
} else {
 // IP ADDRESS NOT FOUND
}
</code></pre>

blocks|key|1624124|text|我会使用正则表达式来表示准确性和灵活性：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1624125|$lines+=+file($blockListFile);
$findIp+=+'119.92.11';

$findIp+=+trim($findIp,+'.');

//+The+number+of+unspecified+IP+classes+(e.g.+for+"192.92.11",+it+would+be+1,
//+but+for+"192.92"+it+would+be+2,+and+so+on).
$n+=+4+-+(substr_count($findIp,+'.')+%2B+1)

foreach+($lines+as+$line)+{
++++if+(preg_match('/%5E'+.+preg_quote($findIp,+'/')+.+'(\.\d{1,3}){0,'+.+$n+.+'}$/',+$line))+{
++++++++//+the+line+matches+the+search+address
++++}+else+{
++++++++//+the+line+does+not+match+the+search+address
++++}
}|code-block|syntax|javascript|1624126|该方法允许搜索任意数量的IP类(例如"192.92.11.45“、"192.92.11”、"192.92"，甚至只是“192个”)。它总是在行的开头匹配，因此，例如，搜索"192.92.11“将不匹配"24.192.92.11”。它也只匹配完整的类，因此搜索"192.92.11“将不匹配"192.92.115”或"192.92.117.21“。|1624127|编辑：|offset|length|style|BOLD|1624128|请注意，此解决方案假定：|1624129|搜索词是在完整类中指定的(例如，搜索"192.92.11“意味着要匹配块列表文件中指定的/%5E192.92.11(\.\d{1,3})?$/)|CODE|1624130|The+in，也可以在完整的类|unordered-list-item|1624131|
中指定|1624132|entityMap^0|0|0|0|0|3|0|0|18|P|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|12|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|13|8|@$K|14|L|15|M|N]]|9|@]|A|$]]|$1|O|3|P|5|6|7|16|8|@]|9|@]|A|$]]|$1|Q|3|R|5|6|7|17|8|@$K|18|L|19|M|S]]|9|@]|A|$]]|$1|T|3|U|5|V|7|1A|8|@]|9|@]|A|$]]|$1|W|3|X|5|6|7|1B|8|@]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]]|Z|$]]

I would use a regular expression for accuracy and flexibility:

<pre><code>$lines = file($blockListFile);
$findIp = '119.92.11';

$findIp = trim($findIp, '.');

// The number of unspecified IP classes (e.g. for "192.92.11", it would be 1,
// but for "192.92" it would be 2, and so on).
$n = 4 - (substr_count($findIp, '.') + 1)

foreach ($lines as $line) {
 if (preg_match('/^' . preg_quote($findIp, '/') . '(\.\d{1,3}){0,' . $n . '}$/', $line)) {
 // the line matches the search address
 } else {
 // the line does not match the search address
 }
}
</code></pre>

This method allows searching for any number of IP classes (e.g. "192.92.11.45", "192.92.11", "192.92", or even just "192"). It will always match at the beginning of the line, so that, for example, searching for "192.92.11" will not match "24.192.92.11". It also only matches full classes, so that searching for "192.92.11" will not match "192.92.115" or "192.92.117.21".

Edit:

Please note that this solution assumes:

<ul>
<li>Your search term is specified in full classes (e.g. searching for "192.92.11" means you want to match <code>/^192.92.11(\.\d{1,3})?$/</code>)</li>
<li>The IPs specified in your block list file are also specified in full classes</li>
</ul>

Couldn't find anything about this on the internet, or stackoverflow?!?

<h2>Basic Example:</h2>

A great example of what I want to know is, how would you create an if statement that returns true if it finds a word or phrase in a sentence.

<h2>Another Example:</h2>

Let's say we have an IP blocklist in an external file. So I presume we'll need to use <code>file_get_contents</code> somewhere in the if statement.

<pre><code>// IP Blocklist
118.92.00
119.92.11
125.23.10
</code></pre>

Ok so that's our example IP blocklist. How would you create an if statement that is able to find the middle IP (119.92.11), even though there is other content there (keeping in mind it could very well change!)?

Get only part of a file in PHP?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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在互联网上找不到任何关于这个的信息，或者是堆栈溢出？！！？基本例子：我想知道的一个很好的例子是，如果在句子中找到一个单词或短语，那么如何创建一个返回true的if语句。另一个例子是：假设我们在外部文件中有一个IP块列表。因此，我想我们需要在if语句中的某个地方使用file_get_contents。// IP Blocklist118.92.00119.92.11125.23.10好的，这是我们的

问在PHP中只获取文件的一部分？
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问在PHP中只获取文件的一部分？
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