:
var F:file of _,
_ , . .. .
:
type Matrix=array[1..10,1..15] of real;
Person=record
FIO:string[20];
group:1..12
end;
var FI: file of integer; //
FM: file of Matrix; //
FP: file of Person; //
C :
| ... | Eof |
: , , . 0.
1) - , .. , , , -.
2) , . Reset Rewrite , , 0- .
function FilePos (F): int64
.
- FilePos(F)=0
- FilePos(F)=FileSize(F)
function FileSize (F): int64
.
procedure Seek (F, n)
n.
- : Seek(F,0)
- : Seek(F,FileSize(F)-1)
procedure Truncate (F)
, .
: Seek(F,0); Truncate(F) : Rewrite(F).
:
var F:File of integer; x:integer;
1
Reset(F);
while not Eof(F) do Read(F,x); //
// FilePos(F)-1
2
Reset(F);
for i:=0 to Filesize(F)-1 do Read(F,x) //
// i.
( )
Reset(F);
for i:=Filesize(F)-1 downto 0 do // i 0-
begin Seek(F,i); Read(F,x) end
Reset(F);
while not Eof(F) do
begin Read(F,x);
if (x xnew) then
begin Seek(FilePos(F)-1); // , x
write(F,xnew) //
|
|
|
end
end
1. , , /
for i:=p+1 to Filesize(F)-1 do //p
begin
Seek(F,i);
read(F,x);
Seek(F,i-1);
write(F,x);
end;
Truncate(F); //
2. , .
Rewrite(Fnew); //
Seek(F,p); //p
while not Eof(F) do
begin
read(F,x);
if (FilePos(F)-1)<>p
then write(Fnew,x);
end;
3. , . . .
Seek(F,Filesize(F)-1); //
Read(F,y); //
Seek(F,p); //p
write(F,y);
Seek(F,Filesize(F)-1);
Truncate(F); //
