#25175 [Opn]: ob_get_length() returns incorrect value

ID: 25175 User updated by: phpbug at paypc dot com Reported By: phpbug at paypc dot com Status: Open Bug Type: Output Control Operating System: Linux 2.4 PHP Version: 4.3.2 New Comment: *ARGH* I hate "thinkoes" -- it should be obvious from context (and perusing my phpconfig) that I've TURNED OFF enable_trans_sid, not turned it on. Upon re-reading my posting (naturally AFTER I'd hit submit), I noted the think-o. My apologies. =Apollyon= Previous Comments: ------------------------------------------------------------------------ [2003-08-21 04:31:10] phpbug at paypc dot com OK, let me put forth some declarations so we're talking apples and apples. My test method: echo -e "GET /legal/tester.php HTTP/1.1\r\nHost: 127.0.0.1\r\n" | nc 127.0.0.1 80 > dump I wish to eliminate any possible "post-processing" or browser-variations. IE: "nc" is netcat, a commonly available network tool. OK, onto the results of my tests. I copied and pasted sniper's code *EXACTLY* as presented, with whitespaces and line spacing as entered. I obtained identical results with both lynx and my netcat method, though lynx probably doesn't support HTTP/1.1 because there was an additional header. With Lynx Version 2.8.3rel.1: HTTP/1.1 200 OK Date: Thu, 21 Aug 2003 09:10:16 GMT Server: Apache/1.3.27 Ben-SSL/1.48 Connection-Type: Keep-Alive Content-Length: 4 Connection: close <<<<<<<<<<<<< Additional header Content-Type: text/html With netcat: HTTP/1.1 200 OK Date: Thu, 21 Aug 2003 09:10:55 GMT Server: Apache/1.3.27 Ben-SSL/1.48 Connection-Type: Keep-Alive Content-Length: 4 Content-Type: text/html In comparing the actual bytes sent over the wire against the advertised content-length, the Content-Length header is correct. If you wish to inspect my PHP build and setup configuration, you may do so at: <http://hollywood.paypc.com/config4phpbugmasters> (I will be removing this after 24 hours.) And yes, it's pretty loaded. And yes, trans_sid is enabled, but in all of my test harnesses which employ sessions, I've enabled cookies - and they are created/used by the browsers involved. ******* AHHHHHHAAAA ******* Arigatoo gozaimashita to Moriyoshi-san for cautioning me to turn on trans_sid, because when I disable it in my global php.ini, the discrepancy disappears! For my "complex" web-application which formerly reported bad sizing, I received the following header (after turning off trans_sid): ---------------------------- HTTP/1.1 200 OK Date: Thu, 21 Aug 2003 09:20:47 GMT Server: Apache/1.3.27 Ben-SSL/1.48 Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0 Pragma: no-cache Set-Cookie: PHPSESSID=a1c8bfb3f409580e57206d7c19eac473; path=/ Expires: Thu, 19 Nov 1981 08:52:00 GMT Content-Length: 2825 Content-Type: text/html -------------------------------- And doing a wc -c on the content-portion matches this size exactly (with my netcat test). Third-party validation via usage of <http://www.ircache.net/cgi-bin/cacheability.py> confirms an exact match of advertised Content-Length and what's actually received. And lastly, and most importantly, the IE "hang" bug while accessing this web application via an intranet is gone. OK, fine, trans_sid broke it. Why? And should it have? I'm suspicious that the Esteemed Moriyoshi-san nailed this specific setting in advance, as if to suspect it being a potential cause for buggage. Inquiring minds want to know - if it's by design, please add it to the documentation and FAQ. I know alot of things about the ob_ functions are unusual and cause some people hardship (of their own making). This one came out of left field. =Apollyon= ------------------------------------------------------------------------ [2003-08-21 00:10:00] moriyoshi@php.net > Set-Cookie: PHPSESSID=2989258979bd07405999448563ef4bfc; path=/ Perhaps you seem to have enabled session.use_trans_sid. If so, first turn it off before trying the above script provided by sniper. ------------------------------------------------------------------------ [2003-08-20 22:54:00] sniper@php.net try this script: <?php ob_start(); ?> foo <?php header("Connection-Type: Keep-Alive"); header('Content-Length: ' . ob_get_length()); ob_end_flush(); echo ob_get_length(); ?> And access it with this command: # lynx -head lynx -dump -head http://localhost/test.php I get this (correct) output: HTTP/1.1 200 OK Date: Thu, 21 Aug 2003 03:52:44 GMT Server: Apache/1.3.27 (Unix) PHP/4.3.3RC5-dev X-Powered-By: PHP/4.3.3RC5-dev Connection-Type: Keep-Alive Content-Length: 4 Connection: close Content-Type: text/html ------------------------------------------------------------------------ [2003-08-20 22:33:34] phpbug at paypc dot com One last thing... this bug report isn't just a pedantic exercise. When I have that defective Content-Length header in the headers, IE 5.00.3700.1000 SP4 under Windows 2000 Profession SP4 "hangs" for a few seconds during a pageview when that header is present. When I comment out the Content-Length header invocation, this problem goes away. NO INTERVENINIG PROXIES ARE INVOLVED - as it's a local intranet without even an intevening router in between the two machines. I am to understand that HTTP pipelining and keep-alive support is dramatically assisted by the presence of this header. I would like to make use of it. I am going to sprinkle my preamble+postamble across a wider mixture of PHP pages on my system (some with DB content and some without) to see if I can find common modes of failure. If any Zend/PHP devs can suggest a more surgical strike, I'd sincerely appreciate it. =Apollyon= ------------------------------------------------------------------------ [2003-08-20 20:45:00] phpbug at paypc dot com Furthermore, when I removed the Keep-Alive header, nothing changes. IN FACT, my preamble file is now: header.inc: ------------------------------ <?php $start_time=gettimeofday(); ob_start(); ?> ------------------------------ footer.inc: ------------------------------ <?php header('Content-Length: ' . ob_get_length()); ob_end_flush(); ?> --------------------------------- The headers output from a page: HTTP/1.1 200 OK Date: Thu, 21 Aug 2003 01:36:53 GMT Server: Apache/1.3.27 Ben-SSL/1.48 Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0 Pragma: no-cache Set-Cookie: PHPSESSID=2989258979bd07405999448563ef4bfc; path=/ Expires: Thu, 19 Nov 1981 08:52:00 GMT Content-Length: 2809 Content-Type: text/html ------------------------------ The real content length is 2890 bytes. I make use of the following PEAR libraries: HTML_Quickform, ADODB session management, and Log (when enabled). I make use of mySQL and ctype() functions throughout my application. I utilise a "user-supplied session function" for PHP to make use of ADODB as opposed to using the built-in default session handler. =Apollyon= ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/25175 -- Edit this bug report at http://bugs.php.net/?id=25175&edit=1