Passing scalars to C functions

[Josef Moellers]

I'm fairly new to the XS business. I have managed to get the skeleton up
(h2xs) and have also managed to write short functions that have ints as
arguments and return strings, but I'd like to pass a full Perl scalar
(my $cdb = pack('C*', 0x12, 0, 0, 0, 128, 0) and retrieve the length
(6) and the bytes themselves in the C function and also return such a
scalar.

How do I do that?

Thanks,

Josef

 

[Josef Moellers]

MODULE = My::XS PACKAGE = My::XS

SV *
my_xs_func(sv)
SV *sv
PREINIT:
const char *bytes;
STRLEN len;
CODE:
bytes = SvPV(sv, len);
RETVAL = sv_2mortal(newSVpvn(bytes, len));
OUTPUT:
RETVAL

Of course, there are lots of other ways, this being Perl. See perlxs for
the details.

Thanks. This works.

Josef