bool get_argval(int, int *);bool get_fargval(int, double *);bool get_cargval(int, char **);void ckargs(const char *, int , char **, int );void fprintf_argv(FILE* );void ck_argc(const char *);void get_argval_min(int c, int *v, int d, int min, const char *msg);void get_argval_max(int c, int *v, int d, int max, const char *msg);void get_argval_nonneg(int ch, int *val, int dflt);void get_argval_pos(int ch, int *val, int dflt);extern char *argv0;