Dateipfad mit \..\ auswerten

[BUG]

Puh, doch schwieriger als gedacht

Delphi-Quellcode:

function collapsePath(path: UTF8String): UTF8String;
const
  delimiters = ['/', '\'];
var
  afterLastDelim: integer;
  writePos: integer;
  readPos: integer;
  skip: integer;
  state: (sNormal, sAfterDelim, sAfterDot, sAfter2Dots);
begin
  state := sAfterDelim;
  writePos := length(path);
  afterLastDelim := writePos;
  skip := 0;
  for readPos := length(path) downto 1 do
  begin
    if path[readPos] in delimiters then
    begin
      if (state = sNormal) or (state = sAfterDelim) then
      begin
        if skip = 0 then
        begin
          path[writePos] := path[readPos];
          dec(writePos);
          afterLastDelim := writePos;
        end else
        begin
          writePos := afterLastDelim;
          dec(skip);
        end;
      end else // not normal
      begin
        writePos := afterLastDelim;
        if state = sAfter2Dots then inc(skip);
      end;
      state := sAfterDelim;
    end else // no delimiter
    begin
      path[writePos] := path[readPos];
      dec(writePos);
      if path[readPos] = '.' then
      begin
        if state = sAfterDelim then state := sAfterDot
        else if state = sAfterDot then state := sAfter2Dots
        else state := sNormal; // third dot
      end else state := sNormal;
    end;
  end;
  if (state = sNormal) or (state = sAfterDelim) then
  begin
    if skip > 0 then
    begin
       writePos := afterLastDelim;
       dec(skip);
    end;
  end else writePos := afterLastDelim;
  if skip > 0 then
  begin
    path[writePos-1] := '.';
    path[writePos] := '.';
    dec(writePos,2);
    dec(skip);
  end;
  while skip > 0 do
  begin
    path[writePos-2] := '.';
    path[writePos-1] := '.';
    path[writePos] := '\';
    dec(writePos,3);
    dec(skip);
  end;
  result := copy(path, writePos+1, length(path));
end;

Macht das was du möchtest?
(Nicht ohne Kontrolle produktiv benutzen, nur ein bisschen getestet.)