ckkeywd
extern int ckkeywd __P((char *strval, char *keyword[], char *defstr,
n = ckkeywd(strval, keyword, deflt, error, help, prompt);
if (n = ckkeywd(strval, keyword, NULL, NULL, NULL, pt))
extern int ckkeywd(char *, char **, char *, char *, char *, char *);