在目录中搜索以查找具有特定文件扩展名的文件

Question

什么是使用php搜索目录并找出目录是否有任何以指定文件扩展名结尾的文件（如mp3或pdf）的最佳方法？我想知道我是否可以用if语句来做到这一点。

Answer 1

使用glob()功能：

foreach (glob("*.{pdf,mp3}", GLOB_BRACE) as $filename) { 
    echo "$filename\n"; 
} 

◾GLOB_BRACE - Expands {a,b,c} to match 'a', 'b', or 'c' 

Answer 2

也看看PHP的SPL DirectoryIterator.

Answer 3

在过复杂的一个简单的任务，这里是一个面向对象的SPL的方式风险处理这个问题。

<?php 
/** 
* Provides a means to pull all files matching the specific pattern within a given folder and at option enumerate all sub folders 
* within the same path. 
*/ 
class FileSearchIterator extends FilterIterator 
{ 
    protected $_path, $_extension, $_startWith, $_endWith; 

    /** 
    * Provides an iterator to a collection of filepath matching the given rules. 
    * 
    * If recursive is true also considers sub directories. 
    * 
    * Use in a foreach loop. 
    * 
    * @param string $path 
    * @param boolean $recursive If set to true recursive sub directories are enumerated. 
    * @param mixed $extension Either a single extension to accept or an array of such, null for no filter 
    * @param mixed $startWith Either a single string that must appear at the beginning of the file name, an array of such or null. 
    * @param mixed $endWith Either a single string that must appear at the end of the file name, an array of such or null. 
    * @throws LogicException 
    * @return FileSearchIterator 
    */ 
    public function __construct($path, $recursive = false, $extension = null, $startWith = null, $endWith = null) 
    { 
     if(! is_dir($path)) throw new LogicException("$path : is not a valid folder accessible to this process"); 

     if(! is_array($extension)) $extension = array($extension); 
     if(! is_array($startWith)) $startWith = array($startWith); 
     if(! is_array($endWith)) $endWith = array($endWith); 

     $this->_path = $path; 
     $this->_extension = $extension; 
     $this->_startWith = $startWith; 
     $this->_endWith = $endWith; 

     $it = $recursive ? new RecursiveDirectoryIterator($path, FilesystemIterator::KEY_AS_PATHNAME | FilesystemIterator::CURRENT_AS_SELF) : new DirectoryIterator($path); 

     if($recursive) parent::__construct(new RecursiveIteratorIterator($it)); 
     else parent::__construct($it);   
    } 

    /** 
    * Filter function implemented for the FilterIterator 
    * 
    * @return bool 
    */ 
    public function accept() 
    {   
     $info = $this->getInnerIterator()->current(); 

     if (!$info instanceof SplFileInfo) return false; 
     if (!$info->isFile() || $info->isDot()) return false; 

     $info = pathinfo($info->getFilename()); 

     if($this->_extension[0] != null) 
     {//only allow specified extensions 
      if(! isset($info['extension']) || $info['extension'] == null) return false; 
      $ext = $info['extension']; 
      if(! in_array($ext,$this->_extension)) return false; 
     } 

     if($this->_startWith[0] != null) 
     {//string match from start of filename 
      $found = false; 
      $file = $info['filename']; 

      foreach($this->_startWith as $filter) 
      { 
       if(strncmp($file, $filter, strlen($filter)) == 0) 
       { 
        $found = true; 
        break; 
       } 
      } 

      if(! $found) return false; 
     } 

     if($this->_endWith[0] != null) 
     {//string match from end of filename 
      $found = false; 
      $file = $info['filename']; 

      foreach($this->_endWith as $filter) 
      { 
       if(substr_compare($file, $filter, -strlen($filter), strlen($filter)) === 0) 
       { 
        $found = true; 
        break; 
       } 
      } 

      if(! $found) return false; 
     } 

     return true; 
    } 
} 

用法：

$fileScanner = new FileSearchIterator(path, true, array('mp3', 'pdf')); 
      foreach($fileScanner as $file) 
      { 
       $file-> //do something 
      }