PHP file operation: methods to obtain files in a directory and calculate relative paths, _PHP tutorial

//获取某目录下所有文件、目录名（不包括子目录下文件、目录名） 
  $handler = opendir($dir); 
  while (($filename = readdir($handler)) !== false) {//务必使用!==，防止目录下出现类似文件名“0”等情况 
    if ($filename != "." && $filename != "..") { 
        $files[] = $filename ; 
      } 
    } 
  } 
  closedir($handler); 
    
//打印所有文件名 
foreach ($filens as $value) { 
  echo $value."<br />"; 
} 

function get_allfiles($path,&$files) { 
  if(is_dir($path)){ 
    $dp = dir($path); 
    while ($file = $dp ->read()){ 
      if($file !="." && $file !=".."){ 
        get_allfiles($path."/".$file, $files); 
      } 
    } 
    $dp ->close(); 
  } 
  if(is_file($path)){ 
    $files[] = $path; 
  } 
} 
   
function get_filenamesbydir($dir){ 
  $files = array(); 
  get_allfiles($dir,$files); 
  return $files; 
} 
   
$filenames = get_filenamesbydir("static/image/"); 
//打印所有文件名，包括路径 
foreach ($filenames as $value) { 
  echo $value."<br />"; 
} 

<&#63;php 
/** 计算path1 相对于 path2 的路径,即在path2引用paht1的相对路径 
* @param String $path1 
* @param String $path2 
* @return String 
*/ 
function getRelativePath($path1, $path2){ 
  $arr1 = explode('/', $path1); 
  $arr2 = explode('/', $path2); 
 
  // 获取相同路径的部分 
  $intersection = array_intersect_assoc($arr1, $arr2); 
 
  $depth = 0; 
 
  for($i=0,$len=count($intersection); $i<$len; $i++){ 
    if(!isset($intersection[$i])){ 
      $depth = $i; 
      break; 
    } 
  } 
 
  // 将path2的/ 转为 ../，path1获取后面的部分，然后合拼 
  $tmp = array_merge(array_fill(0, count($arr2)-$depth-1, '..'), array_slice($arr1, $depth)); 
 
  $relativePath = implode('/', $tmp); 
 
  return $relativePath; 
} 
&#63;> 

<&#63;php 
$path1 = '/home/web/lib/img/cache.php'; 
$path2 = '/home/web/api/img/show.php'; 
 
echo getRelativePath($path1, $path2); // ../../lib/img/cache.php 
&#63;>