Re: [PHP4BETA] Re: [PHP3] Re: [PHP4BETA] Writing Apache modules in PHP

Evan Klinger (evan715@sirius.com) wrote: > Does anyone know how Perl (mod_perl?) does it? Are the modules written > in Perl and then compiled into the server somehow? > -- I'm surprised this is not widely known. From perl.apache.org: # With mod_perl it is possible to write Apache modules entirely in Perl. Perl gives you access to most of the Apache API: http://www.apache.org/docs/misc/API.html # Apache breaks down request handling into a series of steps, more or # less the same way the Netscape # server API does (although this API has a few more stages than NetSite # does, as hooks for stuff I # thought might be useful in the future). These are: # # URI -> Filename translation # Auth ID checking [is the user who they say they are?] # Auth access checking [is the user authorized here?] # Access checking other than auth # Determining MIME type of the object requested # `Fixups' --- there aren't any of these yet, but the phase is intended # as a hook for possible extensions like SetEnv, which don't # really fit well elsewhere. # Actually sending a response back to the client. # Logging the request hese phases are handled by looking at each of a succession of modules, looking to see if each of them has a handler for the phase, and attempting invoking it if so. The handler can typically do one of three things: # -Handle the request, and indicate that it has done so by returning the # magic constant OK. # -Decline to handle the request, by returning the magic integer constant # DECLINED. In this case, # the server behaves in all respects as if the handler simply hadn't been # there. # -Signal an error, by returning one of the HTTP error codes. This # terminates normal handling of the # request, although an ErrorDocument may be invoked to try to mop up, and # it will be logged in # any case. This allows you to do such rocket science as having: http://www.greedy.com/products/5432.html ... which will be indexed by a search engine, vs. http://www.greedy.com/products.html?id=5432 ... which probably will not. Of course, you want the former with the file system efficiency of the latter. mod_perl can do it. The only way I could conceive it right now in mod_php using a hack on the error handler, but that's really about it. Embperl (link on perl.apache.org) is quite a bit like mod_php, except it's written in Perl, and wiggles its way into your pages via mod_perl. Very clever, very cool. It's used on a site we produced like http://www.gopuzzles.com/ . I'm a big fan of PHP's simplicty, though. I think Perl poses a much bigger maintenance problem because it is so easy to write obfuscated code. written in Perl, and does its thing -- ,,, (. .) +--ooO-(_)-Ooo------------ --- -- - - - - | Stephen van Egmond http://bang.dhs.org/