modbus_get_slave - get slave number in the context

       The libmodbus documentation was written by Stéphane Raimbault <stephane.raimbault@gmail.com>

libmodbus v3.1.6                                   12/09/2019                                MODBUS_GET_SLAVE(3)

       The modbus_get_slave() function shall get the slave number in the libmodbus context.

EINVAL
           The libmodbus context is undefined.

       modbus_get_slave - get slave number in the context

       The function shall return the slave number if successful. Otherwise it shall return -1 and set errno to
       one of the values defined below.

modbus_set_slave(3)

intmodbus_get_slave(modbus_t*ctx);