String writing (Scilab gateway)

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, Rhs + 1, iRows, iCols, pstData);
    if(sciErr.iErr)
    {
        printError(&sciErr, 0);
        return 0;
    }

    //free container
    free(pstData);

    //assign allocated variables to Lhs position
    LhsVar(1) = Rhs + 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