//in main function
char *str_out=NULL;

read_smart_attr(device_list[i].name,attr_list, str_out);
printf("test: %s", str_out);


//read_smart_attr function


void
read_smart_attr(char * device, int *attr_list, char *str_out) {
 //skipped lines...
 asprintf(&str_out, "%s: %d,%d - ", attributename, (int)disk->current, (int)disk->worst);
 printf("inside: %s", str_out);
 return;
}