<?php
  $myfile = "./test.txt";

if (is_readable ($myfile)) {
    echo "此文件可读。", "\n";
  } else {
    echo "此文件不可读.", "/n";
  }
  
  if (is_writable ($myfile)) {
    echo "此文件可写。", "/n";
  } else {
    echo "此文件不可写。", "/n";
  }

if (is_executable ($myfile)) {
    echo "此文件可执行!", "\n";
  } else {
    echo "此文件没有可执行权限。", "\n";
  }
?>

<?php
  $myfile = "./test.txt";

if (file_exists ($myfile)) {
    $checksize=filesize ($myfile);
    echo "$checksize";
  } else {
    echo "文件不存在!";
  }
?>