php - file_get_contents grab remote page, content is not updated -

in localhost php file test.php, use php function file_get_contents grab forum index page.

echo file_get_contents('http://www.xx.com/forum.php'); 

when forum data, sunch posting , member changes, refresh test.php, content hasn't changed, want know why?

there number of possible reasons:

• you behind caching proxy server , receiving cached copy of page
  • this can exist @ network or server level
• the target site detects such requests , provides cached versions performance or security reasons
• your browser has cached output of script.

you need examine configuration, talk network administrator, or check own browser's cache find source of problem.