dio_open
(PHP 4 >= 4.2.0, PHP 5 < 5.1.0)
dio_open — Opens a file (creating it if necessary) at a lower level than the C library input/ouput stream functions allow
说明
$filename
, int $flags
[, int $mode
= 0
] ) : resourcedio_open() opens a file and returns a new file descriptor for it.
参数
-
filename
-
The pathname of the file to open.
-
flags
-
The
flags
parameter is a bitwise-ORed value comprising flags from the following list. This value must include one ofO_RDONLY
,O_WRONLY
, orO_RDWR
. Additionally, it may include any combination of the other flags from this list.-
O_RDONLY
- opens the file for read access. -
O_WRONLY
- opens the file for write access. -
O_RDWR
- opens the file for both reading and writing. -
O_CREAT
- creates the file, if it doesn't already exist. -
O_EXCL
- if bothO_CREAT
andO_EXCL
are set and the file already exists, dio_open() will fail. -
O_TRUNC
- if the file exists and is opened for write access, the file will be truncated to zero length. -
O_APPEND
- write operations write data at the end of the file. -
O_NONBLOCK
- sets non blocking mode. -
O_NOCTTY
- prevent the OS from assigning the opened file as the process's controlling terminal when opening a TTY device file.
-
-
mode
-
If
flags
containsO_CREAT
,mode
will set the permissions of the file (creation permissions).mode
is required for correct operation whenO_CREAT
is specified inflags
and is ignored otherwise.The actual permissions assigned to the created file will be affected by the process's umask setting as per usual.
返回值
A file descriptor or FALSE
on error.
范例
Example #1 Opening a file descriptor
<?php
$fd = dio_open('/dev/ttyS0', O_RDWR | O_NOCTTY | O_NONBLOCK);
dio_close($fd);
?>