resource dio_open(string $filename, int $flags[, int $mode = 0])
dio_open() opens a file and returns a new file descriptor for it.
A file descriptor or
FALSE on error.
- string $filename: The pathname of the file to open.
- int $flags: The
flagsparameter is a bitwise-ORed value comprising flags from the following list. This value must include one of
O_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 both
O_EXCLare 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.
- int $mode [ = 0]: If
modewill set the permissions of the file (creation permissions).
modeis required for correct operation when
O_CREATis specified in
flagsand is ignored otherwise.
The actual permissions assigned to the created file will be affected by the process's umask setting as per usual.
Example #1 Opening a file descriptor
$fd = dio_open('/dev/ttyS0', O_RDWR | O_NOCTTY | O_NONBLOCK);