Unit FileUnit;

Interface

Uses Dos;

Function  UpperCase (st:String):String;
Function  ProvFile  (Fname:String):Boolean;
Procedure CopyFile  (Nsour,Ndest:String);
Procedure EraseFile (sour:string);
Procedure MoveFile  (sour,dest:string);


Implementation

 Function UpperCase;
  Var i   : Byte;
      sst : string;
  Begin
   sst:=st;
   While Pos(' ',sst)<>0 do delete(sst,pos(' ',sst),1);
   If sst<>'' Then For i:=1 to length(sst) do sst[i]:=UpCase(sst[i]);
   UpperCase:=sst;
  End;
 Function ProvFile;
  Var F:File;
  Begin
   {$I-}
   Assign(F,Fname);Reset(F,1);Close(F);
   if ioresult <> 0 then provfile:=false else provfile:=true;
   {$I+}
  End;
 Procedure CopyFile;
  Type TBuf      = array[1..65535] of byte;
  Var  sour,dest : file;
       buf       : ^Tbuf;
       flen      : LongInt;
       coun      : Word;
       lett      : Char;

  Procedure NoSpace(letter:char);
   Begin
    Writeln;
    if letter <> ' ' then
     Writeln('Not enough free space on drive ',UpCase(letter),':') else
     Writeln('Not enough free space on default drive.');
    Halt;
   End;

  Begin
   New(buf);
   Assign(sour,nsour);Reset(sour,1);
   flen:=FileSize(Sour);

   if pos(':\',Ndest)<>0 then lett:=UpCase(Ndest[pos(':\',ndest)-1]) else
    lett:=' ';

   if lett in ['A'..'Z'] then
    Begin
     if DiskFree(Ord(lett)-64)<flen then NoSpace(Lett);
    End Else
    Begin
     if DiskFree(0)<flen then NoSpace(Lett);
    End;

   Assign(dest,ndest);Rewrite(dest,1);
   Repeat
    blockread(sour,buf^,65535,coun);
    blockwrite(dest,buf^,coun);
   Until coun<65535;
   Close(sour);Close(dest);
   dispose(buf);
  End;

 Procedure EraseFile;
  Var f : file;
  Begin
   If Provfile(sour) then
    Begin
     assign(f,Sour);erase(f);
    End;
  End;
 Procedure MoveFile;
  Var f : file;
  Begin
   If Not(Provfile(Dest)) then
    Begin
     If UpCase(sour[1])=UpCase(dest[1]) then
      Begin
       assign(f,Sour);rename(f,Dest);
      End Else
      Begin
       CopyFile(sour,dest);
       EraseFile(sour);
      End;
    End;
  End;

 Begin
 End.