For an installation program, I needed to be able to copy files into certain
directories. After having come up with a file-copy solution much like Mr.
Stidolph's, I found myself needing a way to copy a file of any size, without
having to blow the stack on a large file buffer.
To this end, I explored the LZExpand unit and developed the function shown
below. Note that this function expects to find the source file as a
standard DOS LZ-compressed file. (These are the files you find on DOS and
Windows installation disks that look like "SETUP.EX_".) You need to use the
DOS utility COMPRESS to first convert the source file to a COMPRESSed file.
Unfortunately, Delphi does not come with COMPRESS! (Why not, Borland?)
You'll need to grab it from another compiler package (like BP or BC++.)
{ CopyFile returns True on a successful copy, False on failure. }
function CopyFile( src, dest: String): Boolean;
var
s, d: TOFStruct;
fs, fd: Integer;
fnSrc, fnDest: PChar;
begin
src:=src + #0;
dest:=dest + #0;
fnSrc:=@src[1]; { Trick the Strings into being ASCIIZ }
fnDest:=@dest[1];
fs := LZOpenFile( fnSrc, s, OF_READ ); { Get file handles }
fd := LZOpenFile( fnDest, d, OF_CREATE );
if LZCopy( fs, fd ) < 0 then { Here's the magic API call }
Result:=False
else
Result:=True;
LZClose( fs ); { Make sure to close 'em! }
LZClose( fd );
end;