#include <unistd.h> int getopt(int argc, char * const argv[], const char *optstring); extern char *optarg; extern int optind, opterr, optopt; #include <getopt.h> int getopt_long(int argc, char * const argv[], const char *optstring, const struct option *longopts, int *longindex); int getopt_long_only(int argc, char * const argv[], const char *optstring, const struct option *longopts, int *longindex);