获取文件后缀,遍历目录层次
/**
* 5种方式获取文件后缀名
* 这道题其实就是考函数substr() strrchr() array_pop() strrpos() strpos() strrev() explode() pathinfo()
* @param string $filename 要处理的文件名 1.jpg/1.png/1.html/1.php* @return string .php/php*/functionget_ext1($filename)
{returnstrrchr($filename,'.');
}functionget_ext2($filename){returnsubstr($filename,strrpos($filename,'.'));
}functionget_ext3($filename){returnarray_pop(explode('.',$filename));
}functionget_ext4($filename){returnpathinfo($filename,PATHINFO_EXTENSION);
}functionget_ext5($filename){returnstrrev(substr(strrev($filename),0,strpos(strrev($filename),'.')));
}$filename= "1.php";echoget_ext1($filename)."\n";echoget_ext2($filename)."\n";echoget_ext3($filename)."\n";echoget_ext4($filename)."\n";echoget_ext5($filename)."\n";
/**
* 遍历目录(递归)
* @param string $dir 目录名且最后没有/
* @return array $files 整个目录结构*/functionmyScandir($dir)
{$files=array();if($handle=opendir($dir)){while(($file=readdir($handle)) !=false){if($file!= "." &&$file!= ".."){$newDir=$dir."/".$file;if(is_dir($newDir)){$files[$file] = myScandir($newDir);
}else{$files[] =$file;
}
}
}closedir($handle);return$files;
}
}$dir= "/dirname";PRint_r(myScandir($dir));