int fork_pty(struct command_details *details, int sv[], int *maxfd, sigset_t *omask);
int perform_io(fd_set *fdsr, fd_set *fdsw, struct command_status *cstat);
int suspend_parent(int signo);
int fork_pty(struct command_details *details, int sv[], int *maxfd, sigset_t *omask);
int perform_io(fd_set *fdsr, fd_set *fdsw, struct command_status *cstat);
int suspend_parent(int signo);