File (internal function): Difference between revisions
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File(N) | File(N) | ||
The '''File''' | The '''File''' internal function returns the numeric value that specifies the status of file N, where N is a [[File Handle]]. | ||
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====Comments and Examples==== | ====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. | ''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==== | ====Extended Syntax==== | ||
As of | As of BR [[4.20]] file's syntax has been expanded to allow the querying of a windows size and shape. | ||
file( | file(N,"WINDOW_RECT | USABLE_RECT", MAT num-arrayname) | ||
BR distinguishes between window dimensions and the useable area of windows. | BR distinguishes between window dimensions and the useable area of windows. | ||
The above file() reference redimensions num-arrayname to 4 elements and returns | The above file() reference redimensions num-arrayname to 4 elements and returns X (horizontal), Y (vertical), Width, and Height in pixels of either the window | ||
or usable area rectangle. | or usable area rectangle. | ||
file( | file(N,"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). | 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). | ||
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file(101,'WINDOW_RECT',mat x) | file(101,'WINDOW_RECT',mat x) | ||
returns 4 items in mat x | returns 4 items in mat x | ||
*x(1)=left | *x(1)=left | ||
Revision as of 11:23, 24 January 2012
File(N)
The File internal function returns the numeric value that specifies the status of file N, where 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 BR 4.20 file's syntax has been expanded to allow the querying of a windows size and shape.
file(N,"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 X (horizontal), Y (vertical), Width, and Height in pixels of either the window or usable area rectangle.
file(N,"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: