预定义常量
以下常量由本扩展模块定义，因此只有在本扩展模块被编译到
PHP 中，或者在运行时被动态加载后才有效。
-
POSIX_F_OK
(integer)
-
Check whether the file exists.
-
POSIX_R_OK
(integer)
-
Check whether the file exists and has read permissions.
-
POSIX_W_OK
(integer)
-
Check whether the file exists and has write permissions.
-
POSIX_X_OK
(integer)
-
Check whether the file exists and has execute permissions.
-
POSIX_S_IFBLK
(integer)
-
Block special file
-
POSIX_S_IFCHR
(integer)
-
Character special file
-
POSIX_S_IFIFO
(integer)
-
FIFO (named pipe) special file
-
POSIX_S_IFREG
(integer)
-
Normal file
-
POSIX_S_IFSOCK
(integer)
-
Socket
Note:
These constants are available since PHP 5.1.0. Please also note that some
of them may not be available in your system.