Author: William Gerbert

Long file names - short file names

Answer:

Here's a way to convert between short (8.3 DOS file names) and long file names:


1   {$APPTYPE console}
2   
3   program LongShrt;
4   
5   uses
6     Windows, SysUtils;
7   
8   function GetShortName(sLongName: string): string;
9   var
10    sShortName: string;
11    nShortNameLen: integer;
12  begin
13    SetLength(sShortName, MAX_PATH);
14  
15    nShortNameLen := GetShortPathName(PChar(sLongName),
16      PChar(sShortName), MAX_PATH - 1);
17  
18    if nShortNameLen = 0 then
19    begin
20      { handle errors... }
21    end;
22  
23    SetLength(sShortName, nShortNameLen);
24  
25    Result := sShortName;
26  end;
27  
28  function GetLongName(sShortName: string; var bError: boolean): string;
29  var
30    bAddSlash: boolean;
31    SearchRec: TSearchRec;
32    nStrLen: integer;
33  begin
34    bError := False;
35    Result := sShortName;
36    nStrLen := Length(sShortName);
37    bAddSlash := False;
38  
39    if sShortName[nStrLen] = '\' then
40    begin
41      bAddSlash := True;
42      SetLength(sShortName, nStrLen - 1);
43      dec(nStrLen);
44    end;
45  
46    if ((nStrLen - Length(ExtractFileDrive(sShortName))) > 0) then
47    begin
48      if FindFirst(sShortName, faAnyFile, SearchRec) = 0 then
49      begin
50        Result := ExtractFilePath(sShortName) + SearchRec.name;
51        if bAddSlash then
52        begin
53          Result := Result + '\';
54        end;
55      end
56      else
57      begin
58        // handle errors...       bError := True;
59      end;
60      FindClose(SearchRec);
61    end;
62  end;
63  
64  function GetLongName(sShortName: string): string;
65  var
66    s: string;
67    p: integer;
68    bError: boolean;
69  begin
70    Result := sShortName;
71  
72    s := '';
73    p := Pos('\', sShortName);
74    while (p > 0) do
75    begin
76      s := GetLongName(s + Copy(sShortName, 1, p), bError);
77      Delete(sShortName, 1, p);
78      p := Pos('\', sShortName);
79  
80      if (bError) then
81        Exit;
82    end;
83    if sShortName <> '' then
84    begin
85      s := GetLongName(s + sShortName, bError);
86      if bError then
87        Exit;
88    end;
89    Result := s;
90  end;
91  
92  const
93    csTest = 'C:\program Files';
94  
95  var
96    sShort,
97      sLong: string;
98  
99  begin
100   sShort := GetShortName(csTest);
101   WriteLn('Short name for "' + csTest +
102     '" is "' + sShort + '"');
103 
104   WriteLn;
105 
106   sLong := GetLongName(sShort);
107   WriteLn('Long name for "' + sShort + '" is "' + sLong + '"');
108 end.