Teilen von PHP-Kerntechnologieproblemen in PHP-Interviewfragen

<?php
    $fp = fopen("lock.txt","w+");    
if (flock($fp,LOCK_EX)) {        //获得写锁，写数据
        fwrite($fp, "write something");        // 解除锁定
        flock($fp, LOCK_UN);
    } else {        echo "file is locking...";
    }
    fclose($fp);?>

<?php
    // 方案一
    function getExt1($url){
        $arr = parse_url($url);        
//Array ( [scheme] => http [host] => m.sbmmt.com [path] => /abc/de/fg.php [query] => id=1 )

        $file = basename($arr[&#39;path&#39;]);
        $ext = explode(&#39;.&#39;, $file);        
return $ext[count($ext)-1];
    }    // 方案二
    function getExt2($url){
        $url = basename($url);
        $pos1 = strpos($url,&#39;.&#39;);
        $pos2 = strpos($url,&#39;?&#39;);        
if (strstr($url,&#39;?&#39;)) {            
return substr($url,$pos1+1,$pos2-$pos1-1);
        } else {            
return substr($url,$pos1);
        }

    }

    $path = "//m.sbmmt.com/abc/de/fg.php?id=1";    
echo getExt1($path);    
echo "<br />";    
echo getExt2($path);?>

CREATE TABLE category(
cat_id smallint unsigned not null auto_increment primary key comment'类别ID',
cat_name VARCHAR(30)NOT NULL DEFAULT''COMMENT'类别名称',
parent_id SMALLINT UNSIGNED NOT NULL DEFAULT 0 COMMENT'类别父ID')engine=MyISAM charset=utf8;

<?php
    function tree($arr,$pid=0,$level=0){        
static $list = array();        
foreach ($arr as $v) {            //如果是顶级分类，则将其存到$list中，并以此节点为根节点，遍历其子节点
            if ($v[&#39;parent_id&#39;] == $pid) {
                $v[&#39;level&#39;] = $level;
                $list[] = $v;
                tree($arr,$v[&#39;cat_id&#39;],$level+1);
            }
        }        
return $list;
    }
?>

<?php
    header("content-type:text/html;charset=utf-8");

    $script = "以下内容不显示：<script type=&#39;text/javascript&#39;>alert(&#39;cc&#39;);</script>";
    $pattern = &#39;/<script[^>]*?>.*?</script>/si&#39;;    
echo preg_replace($pattern, "脚本内容", $script);//以下内容不显示：脚本内容
?>

<?php
    /**
     * 创建多级目录
     * @param $path string 要创建的目录
     * @param $mode int 创建目录的模式，在windows下可忽略
     */
    function create_dir($path,$mode = 0777)
    {        if (is_dir($path)) {            # 如果目录已经存在，则不创建
            echo "该目录已经存在";
        } else {            # 不存在，创建
            if (mkdir($path,$mode,true)) {                echo "创建目录成功";
            } else {                echo "创建目录失败";
            }
        }
    }?>

<?php
    function my_scandir($dir){
        $files = array();        
if(is_dir($dir)){            
if ($handle = opendir($dir)) {                
while (($flie = readdir($handle))!== false) {                    
if ($flie!="." && $file!="..") {                        
if (is_dir($dir."/".$file)) {
                            $files[$file] = my_scandir($dir."/".$file);
                        } else {
                            $files[] = $dir."/".$file;
                        }
                    }
                }
                closedir($handle);                
return $files;
            }
        }
    }?>

<?php
    function checkDateTime($data){        
if (date(&#39;Y-m-d H:i:s&#39;,strtotime($data)) == $data) {            
return true;
        } else {            
return false;
        }
    }    // 示例
    $data = &#39;2015-06-20 13:35:42&#39;;
    var_dump(checkDateTime($data));//bool(true)

    $data = &#39;2015-06-36 13:35:42&#39;;
    var_dump(checkDateTime($data));//bool(false)?>

$data=array(0=>array('id'=>8,'name'=>'name1'),1=>array('id'=>10,'name'=>'name2'),2=>array('id'=>15,'name'=>'name3')
);

<{section name=test loop=$data start=0 step=1}>
id:<{$data[test].id}><br/>
name:<{$data[test].name}>
<br/>
<br/>
<{sectionelse}>
数组为空
<{/section}>

<{foreach from=$data item=test}>
id:<{$test.id}><br/>
name:<{$test.name}>
<br/>
<br/>
<{foreachelse}>
数组为空
<{/foreach}>