原子读写:pread/pwrite
文件描述符拷贝:
dup => fcntl(fd, F_DUPFD, 0)
dup2 => close(fd2); fcntl(fd, F_DUPFD, fd2);
sync/fsync/fdatasync
原子读写:pread/pwrite
文件描述符拷贝:
dup => fcntl(fd, F_DUPFD, 0)
dup2 => close(fd2); fcntl(fd, F_DUPFD, fd2);
sync/fsync/fdatasync