PHP文件操作类（含获取文件内容及属性，更改文件，文件超出一定大小时删除）

<?php  class fileinfo  {   public $file;   function __construct($f)   {    $this->file = $f;   }   function createfile()   {    touch($this->file) or die("Couldn't create $this->file,sorry!");   }   function modifilefile()   {    $fo = fopen($file,"w") or die("Couldn't open $this->file,sorry!");    if($fo)    {     fwrite($fo,"It's just a test by Adam Li on ".date("D d M Y H:i:s",time())) or die("$this->file isn't writable,sorry!");     fclose($fo);    }   }   function getfileinfo()   {    if(file_exists($this->file))    {     //文件大于1024字节时删除并重新创建空文件：     if(filesize($this->file)>1024)     {      echo "<script>alert('File is more than 1024 bytes and will be deleted soon···')</script>";      if(unlink($this->file))      {       echo "<script>alert('File has been deleted and system will create a same file but empty soon···')</script>";       touch($this->file) or die("Couldn't create ".$this->file);      }           }     //获取文件里的内容，避免再写入时被覆盖：     $con = file_get_contents($this->file);     $fo = fopen($this->file,"w") or die("Couldn't open $this->file,sorry!");     if($fo)     {      //连同文件之前的内容一起写入：      fwrite($fo,$con."<br>It's just a test by Adam Li on ".date("D d M Y H:i:s",time())) or die("$file isn't writable,sorry!");      fclose($fo);     }    }    else//如果文件不存在，直接创建，写入内容：    {     $this->createfile();     $this->modifilefile();    }    //以下是获取文件属性：    //获取文件大小:    echo "<p>文件".$this->file."大小为：<font color=red>".filesize($this->file)." bytes;</font></p>";    //检查是否是文件：    echo "<p>$this->file is ".(is_file($this->file)?"":"not ")."a file</p>";    //检查是否是目录：    echo "<p>$this->file is ".(is_dir($this->file)?"":"not ")."a directory</p>";    //检查文件是否可读:    echo "<p>$this->file is ".(is_readable($this->file)?"":"not ")."readable</p>";    //检查文件是否可写：    echo "<p>$this->file is ".(is_writable($this->file)?"":"not ")."writable</p>";    //检查文件是否可执行：    echo "<p>$this->file is ".(is_executable($this->file)?"":"not ")."executable</p>";    //取得文件的上次访问时间    echo "<p>$this->file was accessed on ".date("D d M Y H:i:s",fileatime($this->file))."</p>";    //取得文件修改时间    echo "<p>$this->file was modified on ".date("D d M Y H:i:s",filemtime($this->file))."</p>";    //取得文件的 inode 修改时间    echo "<p>$this->file was changed on ".date("D d M Y H:i:s",filectime($this->file))."</p>";     //显示此时文件里的所有内容：    echo "<p>文件里的内容是：<font color=red>".file_get_contents($this->file)."</font></p>";   }  }    $obj = new fileinfo("adam.txt");  $obj->getfileinfo();  ?>