Mega Code Archive
Disk operations
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Title: Disk operations
Question: If you want to be sure a disk is in drive, without showing those strange message errors, you should use these functions
Answer:
Here is all the functions you need if you deal with floppies:
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unit lDrives;
interface
uses Forms, Messages, Classes, WinProcs, WinTypes, SysUtils,
Dialogs, Controls;
const
MsgAskDefault = 'Please insert a disk on drive %s:';
MsgWProtected = 'Error: The disk %s is write-protected.';
type
TDriveType = (dtAll,dtFixed,dtRemovable,dtRemote{$IFDEF WIN32},dtCDRom,dtRamDisk{$ENDIF});
function ComposeFileName (Dir,Name:string):string;
function HasDiskSpace({$IFDEF WIN32}Drive: string{$ELSE}Drive: char{$ENDIF}; MinRequired: LongInt): boolean;
function GetDirectorySize(const Path: string): LongInt;
function GetFileSizeByName(const Filename: string): longInt;
function IsDiskRemovable(Drive: char): boolean;
function IsDiskInDrive(Drive: char): boolean;
function IsDiskWriteProtected(Drive: char): boolean;
function AskForDisk(Drive: char; Msg: string; CheckWriteProtected: boolean): boolean;
procedure GetAvailableDrives(DriveType: TDriveType; Items: TStrings);
implementation
function ComposeFileName (Dir,Name:string):string;
var
Separator: string[1];
begin
if (length(Dir) 0) and (Dir[length(Dir)]='\') then
delete(Dir, length(Dir), 1);
if (length(Name) 0) and (Name[1]='\') then
delete(Name, 1, 1);
if Name='' then Separator:='' else Separator:='\';
result:=format('%s%s%s',[Dir,Separator,Name]);
end;
function HasDiskSpace(Drive: {$IFDEF WIN32}string{$ELSE}char{$ENDIF}; MinRequired: LongInt): boolean;
begin
if Drive='' then Drive:='C';
{$IFDEF WIN32}
result:=((GetDriveType(PChar(Drive))0) and
(SysUtils.DiskFree(Ord(UpCase(Drive[1]))-$40)=-1) or
(SysUtils.DiskFree(Ord(UpCase(Drive[1]))-$40)=MinRequired));
{$ELSE}
result:=((GetDriveType(Ord(UpCase(Drive))-$40)0) and
(DiskFree(Ord(UpCase(Drive))-$40)=-1) or
(DiskFree(Ord(UpCase(Drive))-$40)=MinRequired));
{$ENDIF}
end;
function GetDirectorySize(const Path: string): LongInt;
var
S: TSearchRec;
TotalSize: LongInt;
begin
TotalSize:=0;
if FindFirst(ComposeFileName(Path,'*.*'), faAnyFile, S)=0 then
repeat
Inc(TotalSize, S.Size);
until FindNext(S)0;
result:=TotalSize;
end;
function GetFileSizeByName(const Filename: string): longInt;
var
F: File;
begin
AssignFile(F, Filename);
Reset(F,1);
result:=FileSize(F);
CloseFile(F);
end;
function IsDiskRemovable(Drive: char): boolean;
begin
{$IFDEF WIN32}
result:=GetDriveType(PChar(Drive+':\'))=DRIVE_REMOVABLE;
{$ELSE}
result:=GetDriveType(ord(UpCase(Drive))-65)=DRIVE_REMOVABLE;
{$ENDIF}
end;
function IsDiskInDrive(Drive: char): Boolean;
var
ErrorMode: word;
begin
Drive:=Upcase(Drive);
if not (Drive in ['A'..'Z']) then
begin
Result:=False;
Exit;
end;
ErrorMode := SetErrorMode(SEM_FAILCRITICALERRORS);
try
if DiskSize(Ord(Drive) - 64) = -1 then
Result := False
else
Result := True;
finally
SetErrorMode(ErrorMode);
end;
end;
function IsDiskWriteProtected(Drive: char): Boolean;
var
F: File;
ErrorMode: Word;
begin
ErrorMode := SetErrorMode(SEM_FAILCRITICALERRORS);
AssignFile(F,Drive+':\_$.$$$');
try
try
Rewrite(F);
CloseFile(F);
Erase(F);
Result:=False;
except
Result:=True;
end;
finally
SetErrorMode(ErrorMode);
end;
end;
{$IFDEF WIN32}
procedure GetAvailableDrives(DriveType: TDriveType; Items: TStrings);
var
Drive: Integer;
DriveLetter: string;
begin
Items.Clear;
for Drive := 0 to 25 do
begin
DriveLetter := Chr(Drive + ord('A'))+':\';
case DriveType of
dtAll : if GetDriveType(PChar(DriveLetter)) in [DRIVE_REMOVABLE,DRIVE_FIXED,DRIVE_REMOTE,
DRIVE_CDROM,DRIVE_RAMDISK] then
Items.Add(DriveLetter);
dtRemovable: if GetDriveType(PChar(DriveLetter))=DRIVE_REMOVABLE then
Items.Add(DriveLetter);
dtFixed : if GetDriveType(PChar(DriveLetter))=DRIVE_FIXED then
Items.Add(DriveLetter);
dtRemote : if GetDriveType(PChar(DriveLetter))=DRIVE_REMOTE then
Items.Add(DriveLetter);
dtCDRom : if GetDriveType(PChar(DriveLetter))=DRIVE_CDROM then
Items.Add(DriveLetter);
dtRamDisk : if GetDriveType(PChar(DriveLetter))=DRIVE_RAMDISK then
Items.Add(DriveLetter);
end;
end;
end;
{$ELSE}
procedure GetAvailableDrives(DriveType: TDriveType; Items: TStrings);
var
Drive: Integer;
DriveLetter: char;
begin
Items.Clear;
for Drive := 0 to 25 do
begin
DriveLetter := Chr(Drive + ord('A'));
case DriveType of
dtAll : if GetDriveType(Drive) in [DRIVE_REMOVABLE,DRIVE_FIXED,DRIVE_REMOTE] then
Items.Add(DriveLetter+':\');
dtRemovable: if GetDriveType(Drive)=DRIVE_REMOVABLE then
Items.Add(DriveLetter+':\');
dtFixed : if GetDriveType(Drive)=DRIVE_FIXED then
Items.Add(DriveLetter+':\');
dtRemote : if GetDriveType(Drive)=DRIVE_REMOTE then
Items.Add(DriveLetter+':\');
end;
end;
end;
{$ENDIF}
function AskForDisk(Drive: char; Msg: string; CheckWriteProtected: boolean): boolean;
var
Ready : boolean;
begin
Ready:=false; Result:=false;
if Msg='' then Msg:=Format(MsgAskDefault,[Drive]);
while not(Ready) do
try
if IsDiskRemovable(Drive) then
case MessageDlg(Msg, mtConfirmation, [mbOk,mbCancel],0) of
mrOk : ready:=IsDiskInDrive(Drive);
mrCancel: exit;
end
else
Ready:=true;
except
result:=false;
exit;
end;
ready:=false;
while not(Ready) do
try
if CheckWriteProtected and IsDiskWriteProtected(Drive) then
begin
ready:=false;
if MessageDlg(Format(MsgWProtected,[Upcase(Drive)+':']),mtError,[mbRetry,mbCancel],0)=mrCancel then
exit;
end
else
ready:=true;
except
result:=false;
exit;
end;
result:=Ready;
end;
end.
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