SysUtils.ExtractFilePath Function

Returns the drive and directory portions of a file name.

Pascal

function ExtractFilePath(const FileName: string): string;

C++

AnsiString ExtractFilePath(const AnsiString FileName);

File

SysUtils

Description

The resulting string is the leftmost characters of FileName, up to and including the colon or backslash that separates the path information from the name and extension. The resulting string is empty if FileName contains no drive and directory parts.

This function works for multi-byte character systems (MBCS).

C++ Examples:

Copy Code

/*
This example copies a specified old file to a new file.  Add
a TSaveDialog to the form.  Also add two TEdits, two TLabels
and a TButton with the OnClick event named Save1Click. Files
can be saved to and from the app directory by using relative
paths.
*/
void __fastcall TForm1::Save1Click(TObject *Sender)
{
  AnsiString NewFileName =
    ExtractFilePath(Application->ExeName) +
    ExtractFileName(Edit1->Text);
  AnsiString OldFileName =
    ExtractFilePath(Application->ExeName) +
    ExtractFileName(Edit2->Text);
  AnsiString Msg = Format("Copy %s to %s", ARRAYOFCONST((OldFileName, NewFileName)));
  if (MessageDlg(Msg, mtCustom, TMsgDlgButtons() << mbOK << mbCancel, 0) == mrOk)
  {
    TFileStream *OldFile = new TFileStream(OldFileName, fmOpenRead);
    try
    {
      TFileStream *NewFile = new TFileStream(NewFileName, fmCreate);
      try
      {
        NewFile->CopyFrom(OldFile, OldFile->Size);
      }
      __finally
      {
        FreeAndNil(NewFile);
      }
    }
    __finally
    {
      FreeAndNil(OldFile);
    }
  }
}

void __fastcall TForm1::FormCreate(TObject *Sender)
{
  Label3->Caption = "Current directory: " + ExtractFilePath(Application->ExeName);
}

Copy Code

/*
The following code prompts for confirmation before deleting
a file.  Create a file and then click on the button to select
the file with a TOpenDialog.  Click Yes to delete it.
*/
void __fastcall TForm1::Button1Click(TObject *Sender)
{
  OpenDialog1->Title = "Delete File";
  if (OpenDialog1->Execute())
  {
    if (FileExists(OpenDialog1->FileName))
    {
      if (MessageDlg(
        ("Do you really want to delete " + ExtractFileName(OpenDialog1->FileName) + "?"),
        mtConfirmation,
        TMsgDlgButtons() << mbYes << mbNo,
        0,
        mbNo) == mrYes)
        DeleteFile(OpenDialog1->FileName);
    }
    else
      MessageDlg(("File " + ExtractFileName(OpenDialog1->FileName) + " does not exist."), mtConfirmation, TMsgDlgButtons() << mbOK, 0);
  }
}

Delphi Examples:

Copy Code

{
This example copies a specified old file to a new file.  Add
a TSaveDialog to the form.  Also add two TEdits, two TLabels
and a TButton with the OnClick event named Save1Click. Files
can be saved to and from the app directory by using relative
paths.
}
procedure TForm1.FormCreate(Sender: TObject);
begin
  Label3.Caption:= 'Current directory: ' + ExtractFilePath(Application.ExeName);
end;

procedure TForm1.Save1Click(Sender: TObject);
var
  NewFileName, OldFileName: string;
  Msg: string;
  NewFile: TFileStream;
  OldFile: TFileStream;
begin
  NewFileName :=
    ExtractFilePath(Application.ExeName) +
    ExtractFileName(Edit1.Text);
  OldFileName := 
    ExtractFilePath(Application.ExeName) + 
    ExtractFileName(Edit2.Text);
  Msg := Format('Copy %s to %s?', [OldFileName, NewFileName]);
  if MessageDlg(Msg, mtCustom, mbOKCancel, 0) = mrOK then
  begin
    OldFile := TFileStream.Create(
      OldFileName, fmOpenRead or fmShareDenyWrite);
    try
      NewFile := TFileStream.Create(
        NewFileName, fmCreate or fmShareDenyRead);
      try
        NewFile.CopyFrom(OldFile, OldFile.Size);
      finally
        FreeAndNil(NewFile);
      end;
    finally
      FreeAndNil(OldFile);
    end;
  end;
end;

Copy Code

{
The following code prompts for confirmation before deleting
a file.  Create a file and then enter the path and file name
in the textfields.  Click the button to delete it.
}
procedure TForm1.Button1Click(Sender: TObject);
var FileName: string;
begin
  Filename:= Edit1.Text;
  if SysUtils.FileExists(FileName) then
  begin
    if MessageDlg(('Do you really want to delete ' + ExtractFileName(FileName) + '?'), mtConfirmation, [mbYes, mbNo], 0, mbNo) = IDYes then
      DeleteFile(FileName);
  end
  else
    MessageDlg(('File ' + ExtractFileName(FileName) + ' does not exist.'), mtConfirmation, [mbOK], 0);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Edit2.Text:= ExtractFilePath(Application.ExeName);
end;