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Date: Thu, 2 Apr 2009 20:59:47 +0200
Message-ID: <20170a030904021159j7e614bfn38ea5a9ca2791b98@mail.gmail.com>
Subject: Re: APR feature detection
From: Sorin Manolache <sorinm@gmail.com>
To: modules-dev@httpd.apache.org
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On Thu, Apr 2, 2009 at 19:45, Dave Ingram <dave@dmi.me.uk> wrote:
> Hi guys,
>
> Is there any way that my module can detect which APR features are
> enabled in Apache? It relies on DBD, and if that's not available then my
> module just segfaults, which isn't very friendly. I'd prefer to give an
> error message to the user, telling them that DBD is required.
>
> Does anyone have any tips, or should I ask the APR list instead?

dbd does this:
    APR_REGISTER_OPTIONAL_FN(ap_dbd_prepare);
    APR_REGISTER_OPTIONAL_FN(ap_dbd_open);
    APR_REGISTER_OPTIONAL_FN(ap_dbd_close);
    APR_REGISTER_OPTIONAL_FN(ap_dbd_acquire);
    APR_REGISTER_OPTIONAL_FN(ap_dbd_cacquire);

APR_RETRIEVE_OPTIONAL_FN(one of the functions above) should give you
NULL if DBD is absent.

The two macros are declared in apr_optional.h.

S

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