I just moved a site from one host to another. The server environment is very similar (LAMP stack) and all the code worked when it got transferred, except one line. I've mutated it a bit for testing and am still getting very odd results:
<?php
$out = `php ../test/test.php 123 abc`;
?>
When running php ../test/test.php 123 abc from the command line in SSH, it works fine, as expected. And when I run: php testrunner.php (the file which has only the "$out" line above in it) in SSH, it also works as expected.
But once I load testrunner.php from the browser, it just hangs. Using ps aux | grep php to monitor the processes, processes seem to spawn up and die down (truncated for brevity):
myuser 12790 0.0 0.3 259016 45284 . . . 0:00 php ../test/test.php 123 abc
If I modify the "$out" line to be:
<?php
$out = `php ../test/test.php 123 abc &`;
?>
then I cause that script to run in the background. Surprisingly, a few seconds later when I run ps aux | grep php again, it shows the same stuff but with a new PID. I keep running ps aux and keep seeing it with a different PID. This continues for quite some time (several seconds, maybe even a minute).
This is very odd to me, since test.php only has a line to echo some text for testing purposes.
Works fine from the terminal. Hangs and has other weird behavior when invoked from the web. Am I missing something?
(I have evidence by redirecting output to a log file that, when run from the web browser, the PHP script seems to invoke ITSELF instead of the other script, test.php. And when it behaves like this, it doesn't receive any $argv parameters... but when I run it from the command line, all is well! Strange?)
UPDATE: Geez... I was just watching the server processes and the PHP ones of test.php started spawning out of control. They multiplied into the hundreds, maybe thousands, of processes: the server was brought down for a minute, SSH and everything. It's back up now, but I can't explain what's going on. There's no loops in the code and both the files involved are super-simple, isolated for testing purposes...
I'm working with my host as they respond to my support ticket, to see if this is environment-related or what... what could cause this to be happening, simply by changing the server environment?
