I found out:
exec using absolut paths seems to need rights not only on the file executed but on the whole path tree leading to it, which is not allways allowed by the hosters!!!


I run php CGI 4.2.2 on two servers with IIS
on one everything is fine, on the hosting server
the exec command cant find any absolute filepath,
exec("sample.exe"); works
exec("c:\\inetpub\\wwwroot\\sample.exe"); fails without giving error
messages!

on a third server it says "unable to fork"

I've tried a lot, the php.ini  possible restriction settings are not
involved I checked and since it is twice the same file, and in one case
it works.

It must be some difference in the Server configuration. It also can't be
the security settings as documented since the same file is once allowed
once denied.

Im lost in this, does someone know about such problems? how to proceed
to find the problem source?

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