#25523 [Bgs]: fread() reads entire file to memory

ID: 25523 Updated by: phildriscoll@php.net Reported By: psurmano at ucalgary dot ca Status: Bogus Bug Type: Output Control Operating System: Redhat 8.0 PHP Version: 4.3.3 New Comment: Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php Try a flush() after the echo. Previous Comments: ------------------------------------------------------------------------ [2003-09-13 03:34:55] wez@php.net Turn off output buffering.... ------------------------------------------------------------------------ [2003-09-13 01:24:15] psurmano at ucalgary dot ca Description: ------------ When the following code is run in a browser on a very large file php will first read in the entire file into memory and only afterwards will it display a download dialog in the browser. This is even though I'm reading in 8192 bytes at a time. On a large file this results in a delay of several seconds. Using readfile() doesn't have this problem but it is unacceptable since I will need to add code to throttle download speed. Reproduce code: --------------- <?php header("Content-type: application/octet-stream"); header("Content-Disposition: attachment; filename=largeFile"); header("Content-Length: " . filesize("largeFile")); $handle = fopen ("largeFile", "rb"); do { $data = fread($handle, 8192); if (strlen($data) == 0) { break; } echo $data; } while(true); fclose ($handle); ?> Expected result: ---------------- PHP should first show the download dialog and then start reading the file. This is what happens with readfile() Actual result: -------------- The file will first get read entirely into memory resulting in a large delay. Only then is the user prompted with a download dialog. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=25523&edit=1