"HubbleBubble" <phil_simmons@[EMAIL PROTECTED]
> wrote in message
news:1179916962.034090.22760@[EMAIL PROTECTED]
> Hi All,
>
> One thing that I can't figure out is the text vs binary thing.
> As you know in dos a file handle is just an integer. Presumably this
> points to an internal record of type file or does the user need to
> optionally supply a pointer to a file structure?. Is the text record
> structure part of dos or is it handled entirely by pascal?. If it is
> dos how might I tell dos which type of file I want?
>
The difference is made in the filetype
Textfiles are type TEXT in BP7 (or TextFile in Delphi)
Binary files are File of Byte.
You can read a number of bytes and then convert them to any other type by
using one of the following tricks:
- dereference a pointer into a variable of the other type, this will work
with any variable, even large records.
- use a variant record, like
s = record
case Byte of
0: ( sa : array [1..4] of Byte );
1: ( res : Single );
end;
var u: s;
You can now read the four bytes from your binary file, and set them like
u.sa[1]:=byte1; etc., and then access the single precision real with u.res
Turbo Pascal used this trick to access the registers, either 8 bit or 16
bit
wide.
type
Registers = record
case Integer of
0: (AX, BX, CX, DX, BP, SI, DI, DS, ES, Flags: Word);
1: (AL, AH, BL, BH, CL, CH, DL, DH: Byte);
end;
HTH, Matt
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