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Date: Tue, 01 Nov 2005 10:29:21 +0100
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Subject: Re: Question on return_value
From: mike@php.net (Michael Wallner)

Bob Silva wrote:
> Hi,
>=20
> I have an internal function defined that returns an array zval:
> zval *pow_zstring_internal_split(Z_STRVAL_P(ivalue), separator, count, =
0
> TSRMLS_DC);
> =20
>=20
> When I call it like this,  return_value is NULL in userland.
>=20
> return_value =3D pow_zstring_internal_split(Z_STRVAL_P(ivalue), separat=
or,
> count, 0 TSRMLS_CC);

The outta world doesn't care if you let return_value point else where in
your function.  Look up the chapter pointers in your book. Short version:=

You need a pointer to a pointer so that the caller gets another pointer.

> But when I call it like this, it works as expected and an array is retu=
rned
> to userland
>=20
> array =3D pow_zstring_internal_split(Z_STRVAL_P(ivalue), separator, cou=
nt, 0
> TSRMLS_CC);
>=20
> *return_value =3D *array;

Yes, because you change the members of the struct the pointer points at a=
nd
the pointer is still the same of that of the "outta world".

> I'm sure there is an obvious answer, but given my background (or lack
> thereof) in C, I can't figure it out.
>=20
> How does the temporary assignment change things inside the engine?

H=E4? :)

Regards,
--=20
Michael - <mike(@)php.net> http://dev.iworks.at/ext-http/http-functions.h=
tml.gz