Question

I have been experimenting with TMask in Delphi 2010 and it seems to work as expected except in one situation: when the mask name contains [ or ] the mask always seem to return false. For example:

var
  MaskObj : TMask;
begin
  MaskObj:= TMask.Create('c:\[test]\*');
  try
    Result:= MaskObj.Matches('c:\[test]\text');
  finally
    FreeAndNil(MaskObj);
  end;
end;

returns false. …

Yes, [ and ] are legal characters in file name. So if I want to exclude for example all files in c:[test]*, what could I do here? My only solution is to do a StringReplace if [ is detected, but this will be slow for a large number of files:

if (pos('[', Mask)>0) then
begin
  mask:= ReplaceString(Mask, '[','_', etc...
  // and do the same for the file name---
end;

Is there any other approach?

Answer 1

‘[‘ is used to mark the beginning of a set of characters (eg, “[A-Z]”). In order to match ‘[‘ on its own you just need to create it as its own single-character set. ‘]’ doesn’t need to be similarly escaped, since it’s only a special character once a leading ‘[‘ is found. Try C:\[[]test]\*

Edit:

If you’re allowing arbitrary masks you’ll need to use StringReplace(Mask, '[', '[[]', [rfReplaceAll]) for the mask, but not for the filenames. If you never use the [a-z] wildcards I’d just descend from TMask and handle it in the constructor.