feof

If a connection opened by fsockopen() wasn't closed by the server, feof() will wait until a timeout has been reached to return TRUE. The default timeout value is 60 seconds. You may use stream_set_timeout() to change this value.

If passed file pointer is not valid you may get an infinite loop, because EOF fails to return TRUE.

Example 1. feof() example with an invalid file pointer <?php // if file can not be read or doesn't exist fopen function returns FALSE $file = @fopen("no_such_file", "r"); // FALSE from fopen will issue warning and result in infinite loop here while (!feof($file)) { } fclose($file); ?>