String writing (Scilab gateway)

#include "api_scilab.h"
int write_string(char *fname,unsigned long fname_len)
{
	SciErr sciErr;
	//variable info : matrix of string 2 x 3
	int iRows		= 2;
	int iCols		= 3;
	char** pstData	= NULL;
	//data to put in the new variable
	char string11[]	= "may";
	char string21[]	= "be";
	char string12[]	= "the";
	char string22[]	= "with";
	char string13[]	= "puffin";
	char string23[]	= "you";
	//alloc new array
	pstData			= (char**)malloc(sizeof(char*) * iRows * iCols);
	//copy data address to the "main" array
	pstData[0]		= string11;
	pstData[1]		= string21;
	pstData[2]		= string12;
	pstData[3]		= string22;
	pstData[4]		= string13;
	pstData[5]		= string23;

	//create the variable
	sciErr = createMatrixOfString(pvApiCtx, nbInputArgument(pvApiCtx) + 1, iRows, iCols, pstData);
	if(sciErr.iErr)
	{
		printError(&sciErr, 0);
		return 0;
	}

	//free container
	free(pstData);
	//assign allocated variables to Lhs position
    AssignOutputVariable(pvApiCtx, 1) = nbInputArgument(pvApiCtx) + 1;
	return 0;
}

a_ref = "may the puffin be with you ";
b = [];
a = write_string();
for i=1:size(a,"r")
    for j=1:size(a,"c")
        b = b + a(i,j);
        b = b + " ";
    end
end
if b <> a_ref then error("failed"), end