php实现关键词过滤

在php中，可以通过trie_filter扩展实现关键词的过滤，具体操作如下

1.安装libdatrie的依赖库 libiconv

wget https://ftp.gnu.org/pub/gnu/libiconv/libiconv-1.14.tar.gz 
tar zxvf libiconv-1.14.tar.gz 
cd libiconv-1.14
./configure 
make 
make install

2. 安装：libdatrie(需要最低版本为0.2.4）

wget ftp://linux.thai.net/pub/ThaiLinux/software/libthai/libdatrie-0.2.4.tar.gz
tar zxf libdatrie-0.2.4.tar.gz   
cd libdatrie-0.2.4  
./configure --prefix=/usr/local   
make   
make install

编译出现错误 trietool.c:125: undefined reference to `libiconv'

解决办法为：./configure LDFLAGS=-L/usr/local/lib LIBS=-liconv

3.安装trie_filter 扩展

下载源码包 https://github.com/wulijun/php-ext-trie-filter 在这里下载源码包

phpize
./configure --with-php-config=/usr/local/bin/php-config 
make
make install

注意：如果是php7的版本扩展源码请移步至https://github.com/zzjin/php-ext-trie-filter/tree/php7

4.修改 php.ini 文件，添加 trie_filter 扩展：extension=trie_filter.so，重启PHP。

如何在项目中使用关键词过滤

1、做一个后台来录入关键词，将文件保存在服务器，并且生成相对应的tree文件

public function keywordsAction(){
        $file_path = APP_PATH."public/filter/";
        if($this->request->isPost()){
            $keywords = $this->request->get('keywords','trim');
            if(file_put_contents($file_path.'keywords.txt',$keywords)){
                $handle = fopen($file_path.'keywords.txt', 'r');
                // 生成空的trie-tree-filter
                $resTrie = trie_filter_new();
                while(! feof($handle)) {
                    $item = trim(fgets($handle));
                    if (empty($item)) {
                        continue;
                    }
                    // 把敏感词逐个加入trie-tree
                    trie_filter_store($resTrie, $item);
                }
                // 生成trie-tree文件
                $blackword_tree = $file_path.'blackword.tree';
                trie_filter_save($resTrie, $blackword_tree);
                return $this->responseJson();
            }
            return $this->responseJson(300,'操作失败');
        }else{
            $type = $this->request->get('type','trim','add');
            $keywords = '';
            if($type == 'update'){
                $keywords = file_get_contents($file_path.'keywords.txt');
            }
            $this->view->setVar('keywords',$keywords)->pick('Index/keywords');
        }

    }

<?php
class FilterHelper
{

    // trie-tree对象
    private static $_resTrie = null;
    // 字典树的更新时间
    private static $_mtime = null;


    /**
     * 防止初始化
     */
    private function __construct() {}


    /**
     * 防止克隆对象
     */
    private function __clone() {}


    /**
     * 提供trie-tree对象
     *
     * @param $tree_file 字典树文件路径
     * @param $new_mtime 当前调用时字典树的更新时间
     * @return null
     */
    static public function getResTrie($tree_file, $new_mtime) {

        if (is_null(self::$_mtime)) {
            self::$_mtime = $new_mtime;
        }

        if (($new_mtime != self::$_mtime) || is_null(self::$_resTrie)) {
            self::$_resTrie = trie_filter_load($tree_file);
            self::$_mtime = $new_mtime;
        }
        return self::$_resTrie;
    }

    /**
     * 过滤替换关键词
     * @param $content 原字符串
     * @param string $replace_str 替换后的字符
     * @return string
     */
    static public function filter($content,$replace_str = "*"){
        $arrRet = self::isHasKeywords($content);
        $badwords = [];
        foreach($arrRet as $ret){
            $badwords[] = substr($content, $ret[0], $ret[1]);
//            $key = substr($content, $ret[0], $ret[1]);
//            $content = str_replace($key,str_repeat($replace_str,mb_strlen($key)),$content);
        }
        return str_replace($badwords,$replace_str,$content);
    }

    /**
     * 是否有过滤词
     * @param $content
     * @return array
     */
    static public function isHasKeywords($content){
        $arrRet = trie_filter_search_all(self::$_resTrie, $content);
        return $arrRet;
    }
}

2、在项目相应位置调用关键词过滤替换即可

public function testAction(){
        $content = '你果真是个贱人啊';
        $tree_file = APP_PATH."public/filter/blackword.tree";
        clearstatcache();

        // 获取请求时，字典树文件的修改时间
        $new_mtime = filemtime($tree_file);
        $resTrie = FilterHelper::getResTrie($tree_file,$new_mtime);
        echo FilterHelper::filter($content);

    }

 以上就是使用php扩展实现关键词过滤