[Swig-user] Functions writing binary data into buffer

[Jeff L. <jef...@gm...>]

Howdy,

Say I've got a C function, like read, that takes a pointer to a
buffer, and a byte count argument, and writes count bytes into the
buffer. Here is a contrived example:

void read(char *buf, size_t count) {
    memcpy(buf, my_internal_buffer, count);
}

Whats the quickest and easiest way to wrap this function? My target
language is Python but I'd rather not use any language specific
tricks. I figured out how to do it using cmalloc and cdata, but that
feels kludgy. I'd like to be able to say
data = read(4)
and have data be a string containing the binary data.

There are two macros in cstrings.i that come frustratingly close:

%cstring_output_maxsize(parm, maxparm)
^ This Almost does what I want, but it uses strcpy or something and
stops on null chars, which really doesn't work for binary data.

%cstring_output_withsize(parm, maxparm)
^ This is also extremely close except that it expects maxparm to be a
pointer for some reason. I could begrudgingly modify my C code to take
count as a pointer. But does some variation exist that takes a
straight value instead of a pointer?

Is there a straightforward way to do this with typemaps or something?

Thanks,
Jeff

-- 
73 de n1ywb