extern char* stpblk(char *p); 
extern char* getline(char *s, FILE *fp); 
extern int boolarg(char **s_add, char *brk, char *prompt, int deflt); 
extern int chrarg(char **s_add, char *brk, char *prompt, char *legals, int deflt); 
extern double doublearg(char **s_add, char *brk, char *prompt, double mn, double mx, double deflt); 
extern int hexarg(char **s_add, char *brk, char *prompt, int mn, int mx, int deflt); 
extern int intarg(char **s_add, char *brk, char *prompt, int mn, int mx, int deflt); 
extern char *strarg(char **s_add, char *brk, char *prompt, char *deflt, char *buffer); 
extern int stablk(char *string, int prompt_flag); 
extern char *nxtarg(char **s_add, char *brk); 
extern void prstab(void); 
extern int init_cmds(void); 
extern int cmd_exec(int index, char* args); 
extern int cmd_help(int index); 
extern char* strsave(char* s); 
