RSFD (*f_open)(RSET ct, int wflag);
void (*f_close)(RSFD rfd);
void (*f_delete)(RSET ct);
void (*f_rewind)(RSFD rfd);
int (*f_count)(RSET ct);
RSFD (*f_open)(RSET ct, int wflag);
void (*f_close)(RSFD rfd);
void (*f_delete)(RSET ct);
void (*f_rewind)(RSFD rfd);
int (*f_count)(RSET ct);