getopt(分析命令行参数)
#include <unistd.h> int getopt(int argc, char * const argv[], const char *optstring);
isatty(判断文件描述词是否是为终端机)
#include <unistd.h> int isatty(int fd);
poll(I/O多工机制)
#include <poll.h> int poll(struct pollfd *fds, nfds_t nfds, int timeout);
select(I/O多工机制)
#include <sys/select.h> int select(int nfds, fd_set *restrict readfds, fd_set *restrict writefds, fd_set *restrict errorfds, struct timeval *restrict timeout);
ttyname(返回一终端机名称)
#include <unistd.h> char *ttyname(int fd);