How to retrieve the parameters of the current thread

Many useful functions of the command interpreter need to know what is the thread from which they are called, i.e. what is the corresponding flow_data structure. For instance the functions convert_int and convert_float, that are used to parse numerical arguments of commands, need that, because they can use local variables, i.e. variables that are specific to a thread (cf. 10.2). In a function corresponding to a command a pointer the flow_data structure is contained in argv[-1]. For instance

int MyCom_cmd(int argc, char *argv[])
{
    flow_data    *flow_interp;

    flow_interp = (flow_data *) argv[-1];
    .
    .
    .
}

If a command is emulated inside a function it is better to send it a pointer to the current flow_data structure. For instance if we want to emulate a command corresponding to the function com_cmd, which needs two arguments, we proceed like this :

    char   *k[4];    /* will contain the arguments */

    k[0] = (char *) flow_interp  /* the pointer to the flow_data structure */
/* Then we fill k with the other arguments, the first being the name of
   the emulated command */
       .
       .
       .
/* Then we call the command */
   com_cmd(3, k + 1);
       .
       .
       .