Hi,

I have written a dynamic library in c in which I have some functions of this kind:

int MyFunction(unsigned char *input, unsigend char *output); where input is a pointer to an unsigned char which holds the content of a binary file. Therefore I can't treat it as a pointer to a string (because of the '\0') in which case I may lose some data.
output is as well a pointer to an unsigned char (not a NULL terminated string either).

Now, I would like to call such functions from a Perl program. I am using SWIG in order to wrap these library functions. However, since SWIG can't do the job 100% right, the 'unsigned char *' type is not treated properly. As far as I know, there is a way to overcome this problem, which is (maybe among different methods) to use 'typemap'.

My question: How can I use 'typemap' so that I can receive and return through my function's arguments 'pointers to unsigned char' (or to a string if you prefer) preferably without passing the length of the string? (I found some converstion functions such as SvPV and sv_setpv, but I am not sure that they do exactly what I want). I would like if it possible to make no change at all to my c functions.

Thanks very much for your help ( I am new to Perl and to SWIG)...

Arnaud

In reply to Calling c functions from perl... by ajaffres

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