How do you automatically replace keywords on the web page? This is a common demand. Today, we look at how to use php to access web content and automatically replace keywords. It will be discussed progressively from the following nine areas。
1. Access to web content
In php, you can use the curl function or the file get contens function to access the content of the web page. Of these, the curl function supports more options, but the file get contents function is easier to use and requires only one url parameter. For example:
Php$url =';$co= file get coNtents ($url);
2. Analysis of HTML
When you get the content on the web page, we need to parse HTML and find the key words that need to be replaced. In php, we can use domdDocumentation and domxpath categories to interpret HTML. For example:
Php$doc = new domdDocument(); $doc->loadHTML ($content); $xpath = new domxpath ($doc); $nodes = $xpath->query ('//p');foreach ($nodes as $node) {echo $node->nodeValue;}
3. Search for keywords
After the HTML resolution, you can find keywords using regular expressions or string functions. For example:
Pp$keywords = array ('example','test');foreach ($keywords as $keyword) {$pattern='/\b'. Preg quote ($keyword).'b/i'; if (preg metch ($pattern, $content)}
4. Replacement of keyword
When you find a keyword, you can replace it with a string function. For example:
Php$keywords = allay ('example','test');foreach ($keywords as $keyword) {$co== sync, corrected by elderman ==
5. Filter HTML tags
Sometimes we need to filter HTML labels and keep text only. In php, we can use the stip tags function to filter HTML tags. For example:
Php$coNent = strip tags ($content);
Coding conversion
If the coding of the web page is inconsistent with the coding of the current script, we need a code conversion. In php, we can use the iconv function or the mb convert encoding function to convert the code. For example:
Php$co= mb convert encoding;
7. Addressing anomalies
When accessing web content, a variety of anomalies may arise, such as network connectivity errors, overtime, etc. In php, we can use the terry-catch statement to deal with anomalies. For example:
Phptry {$co)= file get co{\chffffff}{\ch00ffff} catch
8. Cache results
If we need frequent access to the content of the same page and treat it the same way, we can consider the outcome of the cache and avoid duplication of access and processing. In the php, we can do it using a cache system like memcached or redis. For example:
Php$key = md5 ($url); $cache = new memcached(); $cache->addserver ('localhost', 11211); if (!$co)Nent =$cache->get ($key){$co)= file get coNtents ($url); $cache->set ($key, $content, 3600);//cache 1 hour}
Performance optimization
In dealing with a large number of web content, we need to consider performance optimization. For example, we can use multiple threads or walk ios to improve co-activity; we can use caches or cdns to reduce server loads; we can use opcode caches or accelerators to increase php script speed, etc。
The above is the use of php to access web content and automatically replace all keyword content. I hope this will help you。
