PHP uses strpos function to block keyword programs_PHP tutorial

When we make message boards, we often need to block keywords. Below I will introduce how to use txt to save the keywords to be blocked, and then filter them based on the data submitted by the user.

Look at the strpos function first

The strpos() function returns the position of the first occurrence of a string in another string.

If the string is not found, return false.

Grammar

strpos(string,find,start) parameter description
string required. Specifies the string to be searched for.
find required. Specifies the characters to search for.
start is optional. Specifies the location from which to start the search.

Tips and Notes

Note: This function is case sensitive. For case-insensitive searches, use the stripos() function.

Example

The code is as follows

Copy code

代码如下	复制代码
echo strpos("Hello world!","wo"); ?>

echo strpos("Hello world!","wo"); ?>

1. Write the keywords specifically in a text file, one per line. There is no limit to the number. Write as many as you want.

2. PHP reads the keyword text and stores it in an array

3. Traverse the keyword array and use the strpos function one by one to see if there are keywords in the content. If there are keywords, return true, if not, return false

代码如下

复制代码

/**  * PHP中用strpos函数过滤关键字  * 琼台博客  */ // 关键字过滤函数 function keyWordCheck($content){         // 去除空白     $content = trim($content);         // 读取关键字文本     $content = @file_get_contents('keyWords.txt');         // 转换成数组     $arr = explode("n", $content);         // 遍历检测     for($i=0,$k=count($arr);$i                 // 如果此数组元素为空则跳过此次循环         if($arr[$i]==''){               continue;            }                   // 如果检测到关键字，则返回匹配的关键字,并终止运行         if(@strpos($str,$arr[$i])!==false){             //$i=$k;                return $arr[$i];         }        }         // 如果没有检测到关键字则返回false        return false; }     $content = '这里是要发布的文本内容。。。';   // 过滤关键字 $keyWord =  keyWordCheck($content);   // 判断是否存在关键字 if($keyWord){         echo '你发布的内容存在关键字'.$keyWord; }else{         echo '恭喜！通过关键字检测';         // 往下可以进行写库操作完成发布动作。 }

The PHP code is as follows

The code is as follows

Copy code

/** * Use strpos function to filter keywords in PHP * Qiongtai Blog ​*/ // Keyword filter function function keyWordCheck($content){                                                                                                                        // Remove white space $content = trim($content); ​​​​ //Read keyword text $content = @file_get_contents('keyWords.txt');                 // Convert to array $arr = explode("n", $content); // Traversal detection for($i=0,$k=count($arr);$i // If the array element is empty, skip this loop If($arr[$i]==''){ Continue; } // If a keyword is detected, return the matching keyword and terminate the operation If(@strpos($str,$arr[$i])!==false){                      //$i=$k;                                                      return $arr[$i];                                                                       } // Return false if no keyword is detected Return false; } $content = 'Here is the text content to be published. . . '; // Filter keywords $keyWord = keyWordCheck($content); // Determine whether the keyword exists if($keyWord){ echo 'The content you posted contains keywords'.$keyWord; }else{ echo 'Congratulations! By keyword detection'; // You can perform the operation of the database to complete the release action. }

After writing the code, I deliberately wrote a keyword content in the variable $content, and then ran it and found that no keyword was detected. The execution result was passed, and other prohibited keywords were passed.
Depressed, I started to judge if there was something wrong
Encoding problem? Immediately open the keyWord.txt file again with Notepad, and then save it in UTF-8 format. The result still didn't work.
Didn't get the text content of keyWord.txt? Immediately print_r() found that it was read normally and converted into an array line by line.
So, I declared the keyword array directly in the program

The code is as follows

Copy code

代码如下

复制代码

/**  * PHP中用strpos函数过滤关键字  * 琼台博客  */ // 关键字过滤函数 function keyWordCheck($content){         // 去除空白     $content = trim($content);         // 读取关键字文本     //$content = @file_get_contents('keyWords.txt');         // 转换成数组     //$arr = explode("n", $content);         // 直接在程序中声明关键字数组         $arr = array('关键字1','关键字2','关键字3','关键字4'...);         // 遍历检测     for($i=0,$k=count($arr);$i                 // 如果此数组元素为空则跳过此次循环         if($arr[$i]==''){               continue;            }                   // 如果检测到关键字，则返回匹配的关键字,并终止运行         if(@strpos($str,$arr[$i])!==false){             //$i=$k;                return $arr[$i];         }        }         // 如果没有检测到关键字则返回false        return false; }   $content = '这里是要发布的内容，含有关键字2'; // 过滤关键字 $keyWord =  keyWordCheck($content);   // 判断是否存在关键字 if($keyWord){         echo '你发布的内容存在关键字【'.$keyWord.'】'; }else{         echo '恭喜！通过关键字检测';         // 往下可以进行写库操作完成发布动作。 } // 程序运行结果：你发布的内容存在关键字【关键字2】 // 程序正常

/** * Use strpos function to filter keywords in PHP * Qiongtai Blog ​*/ // Keyword filter function function keyWordCheck($content){                                                                                                                        // Remove white space $content = trim($content); ​​​​ //Read keyword text //$content = @file_get_contents('keyWords.txt');                 // Convert to array //$arr = explode("n", $content); ​​​​ // Declare the keyword array directly in the program ​​​​ $arr = array('Keyword 1','Keyword 2','Keyword 3','Keyword 4'...); // Traversal detection for($i=0,$k=count($arr);$i // If the array element is empty, skip this loop If($arr[$i]==''){ Continue; } // If a keyword is detected, return the matching keyword and terminate the operation If(@strpos($str,$arr[$i])!==false){                      //$i=$k;                                                      return $arr[$i];                                                                       } // Return false if no keyword is detected Return false; } $content = 'Here is the content to be published, containing keyword 2'; // Filter keywords $keyWord = keyWordCheck($content); // Determine whether the keyword exists if($keyWord){ echo 'The content you posted contains the keyword ['.$keyWord.']'; }else{ echo 'Congratulations! By keyword detection'; // You can perform the operation of the database to complete the release action. } // Program execution result: The content you posted contains the keyword [Keyword 2] // The program is normal

If you declare a keyword array in PHP, it will work, but if you read a text file, it will not work. What the hell?
When I was puzzled, I thought, could it be caused by the content read from the text file having spaces or line breaks not being filtered? So I added a trim function

to the traversal matching.

After adding the trim() function to filter out the blanks, the test passed. It turned out that the problem was here after messing around for a long time.

The code is as follows

代码如下

复制代码

/**  * PHP中用strpos函数过滤关键字  * 琼台博客  */ // 关键字过滤函数 function keyWordCheck($content){         // 去除空白     $content = trim($content);         // 读取关键字文本     $content = @file_get_contents('keyWords.txt');         // 转换成数组     $arr = explode("n", $content);         // 遍历检测     for($i=0,$k=count($arr);$i                 // 如果此数组元素为空则跳过此次循环         if($arr[$i]==''){               continue;            }                   // 如果检测到关键字，则返回匹配的关键字,并终止运行                 // 这一次加了 trim()函数         if(@strpos($str,trim($arr[$i]))!==false){             //$i=$k;                return $arr[$i];         }        }         // 如果没有检测到关键字则返回false        return false; }     $content = '这里是要发布的文本内容。。。';   // 过滤关键字 $keyWord =  keyWordCheck($content);   // 判断是否存在关键字 if($keyWord){         echo '你发布的内容存在关键字'.$keyWord; }else{         echo '恭喜！通过关键字检测';         // 往下可以进行写库操作完成发布动作。 }

Copy code

/**

* Use strpos function to filter keywords in PHP * Qiongtai Blog ​*/ // Keyword filter function function keyWordCheck($content){                                                                                                                        // Remove white space $content = trim($content); ​​​​ //Read keyword text $content = @file_get_contents('keyWords.txt');                 // Convert to array $arr = explode("n", $content); // Traversal detection for($i=0,$k=count($arr);$i // If the array element is empty, skip this loop If($arr[$i]==''){

Continue;

}

// If a keyword is detected, return the matching keyword and terminate the operation // This time I added the trim () function If(@strpos($str,trim($arr[$i]))!==false){                      //$i=$k;                                                      return $arr[$i];                                                                       } // Return false if no keyword is detected Return false; } $content = 'Here is the text content to be published. . . '; // Filter keywords $keyWord = keyWordCheck($content); // Determine whether the keyword exists if($keyWord){ echo 'The content you posted contains keywords'.$keyWord; }else{ echo 'Congratulations! By keyword detection'; // You can perform the operation of the database to complete the release action. } http://www.bkjia.com/PHPjc/629646.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/629646.htmlTechArticleWhen we make message boards, we often need to block keywords and some keywords. Let me introduce the use of txt saving To block keywords, then filter based on user-submitted data. First...