PHP函数eval（）包含大量代码

I am having problems using eval() with a large PHP file.

This code is working fine:

<?php
$str = file_get_contents('short_code.php');
eval($str);
?>

but

<?php
$str = file_get_contents('long_code.php');
eval($str);
?>

does not work. I get the following error:

PHP Parse error:  syntax error, unexpected '4' (T_LNUMBER) in /var/www/html/long_code.php(1516) : eval()'d code

Notes:

1. files short_code.php and long_code.php work fine without eval() and do not have any syntax errors
2. when I used eval(), I removed <?php and ?> tag from start/end files
3. short_code.php has 147 Lines and 16036 Characters. long_code.php has 1517 Lines and 181778 Characters.

Is this problem caused by a large file (long_code.php), or by something else?

Please , try to use the following code and don't remove <?php and ?> tags from start/end files that you get :

  <?php
   $str = file_get_contents('long_code.php');
   eval('?>'.$str.'<?php;');
   ?>