6.9lseek函数的原型函数为说明 A: intlseek(constchar*pathname,flags,intperms) B: ssize_tlseek(intfd,void*buf,size_tcount) C: FILE*lseek(constchar*path,constchar*mode) D: off_tlseek(intfd,off_toffset,intwhence)

6.10open函数的原型函数为说明 A: intopen(constchar*pathname,flags,intperms) B: ssize_topen(intfd,void*buf,size_tcount) C: FILE*open(constchar*path,constchar*mode) D: off_topen(intfd,off_toffset,intwhence)

6.7fcntl函数的原型函数为说明 A: intfcntl(constchar*pathname,flags,intperms) B: intfcntl(intfd,intcmd,structflock*lock) C: FILE*fcntl(constchar*path,constchar*mode) D: intfcntl(intnumfds,fd_set*readfds,fd_set*writefds,fd_set*exeptfds,structtimeval*timeout)