PHP编程文件处理类SplFileObject和SplFileInfo用法实例分析

$file = new SplFileObject("misc.txt", 'r+');
while (!$file->eof()) {
  echo $file->current();
  $file->next();
}
//关闭文件对象
$file = null;

/**
 * 获取文件指定行数范围数据
 * @param unknown $filename 文件名称
 * @param number $startLine 开始行
 * @param number $endLine  结束行
 * @param string $method
 * @return multitype:
 */
function getFileLines($filename, $startLine = 1, $endLine = 20, $method = 'rb'){
  $content = array();
  $count = $endLine - $startLine;
  $fp = new SplFileObject($filename, $method);
  $fp->seek($startLine - 1); // 转到第N行, seek方法参数从0开始计数
  for ($i = 0; $i <= $count; ++$i) {
    $content[] = $fp->current(); // current()获取当前行内容
    $fp->next(); // 下一行
    if($fp->eof()) {
      array_pop($content);
      break;
    }
  }
  return array_filter($content); // array_filter过滤：false,null,''
}
/**
 * 获取文章最后一行内容
 * @param string $res 文件路径/名
 */
function get_last_line($res) {
  $fp = fopen($res, 'r');
  if (false == $fp) {
    return 'error';
  }
  fseek($fp,-1,SEEK_END);
  $s = '';
  while(($c = fgetc($fp)) !== false)
  {
    if($c == "\n" && $s) break;
    $s = $c . $s;
    fseek($fp, -2, SEEK_CUR);
  }
  fclose($fp);
  return $s;
}