oo1.php

<?php


class File {
  private $fp = null;

  function __construct($path) {
    $this->path = $path;
  }

  function open($mode) {
    if($this->fp) {
      throw new Exception('file is already opened');
    }
    $this->fp = fopen($this->path, $mode);
  }

  function close() {
    if(! $this->fp) {
      throw new Exception('file is not opened');
    }
    fclose($this->fp);
  }

  function puts($data) {
    if(! $this->fp) {
      throw new Exception('file is not opened');
    }
    fputs($this->fp, $data);
  }

  function read() {
    return file_get_contents($this->path);
  }

  static function openWith($filepath, $mode, $fn) {
    $file = new self($filepath);
    $file->open($mode);
    $fn($file);
    $file->close();
  }
}


$file = new File('/tmp/a.txt');
$file->open('a');
foreach(range(1,10) as $n) {
  $file->puts("{$n}\n");
}
$file->close();
echo $file->read(); // 1\n2\n ... 10\n


File::openWith('/tmp/b.txt', 'a', function($file) {
  $file->puts("aaa\n");
});