Informix DataBlade API Programmer's Manual DataBlade API Function Descriptions

The mi_file_open() function opens an operating-system file.

mi_integer mi_file_open(filename, open_flags, open_mode)

const char *filename;

mi_integer open_flags;

mi_integer open_mode;

filename	is the pathname of the file to be opened.
open_flags	is an integer bit mask that can be any of the open flags that the operating-system open command supports: UNIX open(2) or Windows NT _open.
open_mode	is the file open mode in a format that the operating-system open command supports: UNIX open(2) or Windows NT _open.

Valid in Client LIBMI Application?	Valid in User-Defined Routine?
Yes	Yes

The mi_file_open() function opens the filename file in the access mode that open_flags specifies and the open mode that open_mode specifies. It returns an integer file descriptor to this open file, through which you access an operating-system file. The mi_file_open() function is the constructor function for a file descriptor. The mi_file_open() function allocates a new file descriptor for the duration of the client session.

The file ownership (owner and permissions) that open_mode specifies must be compatible with what open_flags specifies and what the operating-system open command supports.

From a C UDR, mi_file_open() can access files on the server computer. The function assumes the file ownership of the server environment.

In a client LIBMI application, mi_file_open() assumes the file ownership of the application user.

You can include environment variables in the filename path with the following syntax:

$ENV_VAR

The mi_file_open() function passes the open_flags argument directly to the underlying operating-system call that opens a file. Therefore, the open_flags values must match those that your operating-system call supports.

The mi_file_open() function does not throw an MI_Exception event when it encounters a runtime error. Therefore, it does not cause callbacks to be invoked.

See the descriptions of the following functions: mi_file_allocate() and mi_file_close().

For more information, see Opening a File.