注意:
Please note that some of them may not be available on your system.
POSIX_S_IFBLK
(int)
Block special file
POSIX_S_IFCHR
(int)
Character special file
POSIX_S_IFIFO
(int)
FIFO (named pipe) special file
POSIX_S_IFREG
(int)
Normal file
POSIX_S_IFSOCK
(int)
Socket