File (internal function)
File(N)
The File internal function will return the numeric value that specifies the status of file N. N is a File Handle.
| -1 | File not opened. |
| 0 | Operation performed successfully. |
| 10 | End of file occurred during input. |
| 11 | End of file occurred during output. |
| 20 | Transmission error during input. |
| 21 | Transmission error during output. |
Comments and Examples
Print File(N) will return -1 when the file N is not opened. File(N) can be used to separate input from output errors in file processing, including communications files.
Extended Syntax
As of Business Rules! 4.20 file's syntax has been expanded to allow the querying of a windows size and shape.
file(nn,"WINDOW_RECT | USABLE_RECT", MAT num-arrayname)
BR distinguishes between window dimensions and the useable area of windows.
The above file() reference redimensions num-arrayname to 4 elements and returns nX (horizontal), Y (vertical), Width, and Height in pixels of either the window or usable area rectangle.
file(nn,"FONTSIZE", MAT num-arrayname)
This FONTSIZE reference returns a two element array with the height and width of each fixed character position in pixels (used for positioning and sizing controls).
extended syntax examples
file(101,'WINDOW_RECT',mat x)
returns 4 items in mat x
- x(1)=left
- x(2)=top
- x(3)=width
- x(4)=height
See Also
For additional information about files, see the following: