Contributor: SWAG SUPPORT TEAM
{ Following is some code I've thrown together , which has to find a
sequence of 4 Characters in a large buffer - non-Text data. The buffer
is 4096 Characters, and the sequence(s) I'm searching For could be
anywhere in it, and may be found numerous times. I suspect this code is
pretty inefficient, but I can't think of anything better. (Yep, this is
to work With the ZIP directory at the end of the File...)
So, I'm looking For a better way to code this process. I know that
Pos won't work, so this brute-Force is what I came up with. Anything
better? Thanks...
}
Const CFHS : String[4] = 'PK'#01#02; { CENTRAL_File_HEADER_SIGNATURE }
ECDS : String[4] = 'PK'#05#06; { end_CENTRAL_DIRECtoRY_SIGNATURE }
Var S4 : String[4];
FOUND : Boolean;
QUIT : Boolean; { "end" sentinel encountered }
begin
FETCH_NAME; Assign (F,F1); Reset (F,1); C := 1; HSize := 0;
FSize := FileSize(F);
I := FSize-BSize; { Compute point to start read }
Seek (F,I); BlockRead (F,BUFF,BSize,RES); { ZIP central directory }
S4[0] := #4; C := 0;
Repeat
FOUND := False; { search For CENTRAL_File_HEADER_SIGNATURE }
Repeat
Inc (C); Move (BUFF[C],S4[1],4); FOUND := S4 = CFHS;
QUIT := S4 = ECDS;
Until FOUND or QUIT;
end.