MdeModulePkg: Initial UDF/ECMA-167 file system support

[mirror_edk2.git] / MdeModulePkg / Universal / Disk / UdfDxe / FileName.c

/** @file\r
  Helper functions for mangling file names in UDF/ECMA-167 file systems.\r
\r
  Copyright (C) 2014-2017 Paulo Alcantara <pcacjr@zytor.com>\r
\r
  This program and the accompanying materials are licensed and made available\r
  under the terms and conditions of the BSD License which accompanies this\r
  distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT\r
  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
**/\r
\r
#include "Udf.h"\r
\r
CHAR16 *\r
TrimString (\r
  IN CHAR16    *String\r
  )\r
{\r
  CHAR16       *TempString;\r
\r
  for ( ; *String != L'\0' && *String == L' '; String++) {\r
    ;\r
  }\r
\r
  TempString = String + StrLen (String) - 1;\r
  while ((TempString >= String) && (*TempString == L' ')) {\r
    TempString--;\r
  }\r
\r
  *(TempString + 1) = L'\0';\r
\r
  return String;\r
}\r
\r
VOID\r
ReplaceLeft (\r
  IN CHAR16         *Destination,\r
  IN CONST CHAR16   *Source\r
  )\r
{\r
  CONST CHAR16      *EndString;\r
\r
  EndString = Source + StrLen (Source);\r
  while (Source <= EndString) {\r
    *Destination++ = *Source++;\r
  }\r
}\r
\r
CHAR16 *\r
ExcludeTrailingBackslashes (\r
  IN CHAR16                    *String\r
  )\r
{\r
  CHAR16                       *TempString;\r
\r
  switch (*(String + 1)) {\r
  case L'\\':\r
    break;\r
  case L'\0':\r
  default:\r
    String++;\r
    goto Exit;\r
  }\r
\r
  TempString = String;\r
  while (*TempString != L'\0' && *TempString == L'\\') {\r
    TempString++;\r
  }\r
\r
  if (TempString - 1 > String) {\r
    ReplaceLeft (String + 1, TempString);\r
  }\r
\r
  String++;\r
\r
Exit:\r
  return String;\r
}\r
\r
/**\r
  Mangle a filename by cutting off trailing whitespaces, "\\", "." and "..".\r
\r
  @param[in] FileName Filename.\r
\r
  @retval @p FileName Filename mangled.\r
\r
**/\r
CHAR16 *\r
MangleFileName (\r
  IN CHAR16        *FileName\r
  )\r
{\r
  CHAR16           *FileNameSavedPointer;\r
  CHAR16           *TempFileName;\r
  UINTN            BackslashesNo;\r
\r
  if (FileName == NULL || *FileName == L'\0') {\r
    FileName = NULL;\r
    goto Exit;\r
  }\r
\r
  FileName = TrimString (FileName);\r
  if (*FileName == L'\0') {\r
    goto Exit;\r
  }\r
\r
  if ((StrLen (FileName) > 1) && (FileName[StrLen (FileName) - 1] == L'\\')) {\r
    FileName[StrLen (FileName) - 1] = L'\0';\r
  }\r
\r
  FileNameSavedPointer = FileName;\r
\r
  if (FileName[0] == L'.') {\r
    if (FileName[1] == L'.') {\r
      if (FileName[2] == L'\0') {\r
        goto Exit;\r
      } else {\r
        FileName += 2;\r
      }\r
    } else if (FileName[1] == L'\0') {\r
      goto Exit;\r
    }\r
  }\r
\r
  while (*FileName != L'\0') {\r
    if (*FileName == L'\\') {\r
      FileName = ExcludeTrailingBackslashes (FileName);\r
    } else if (*FileName == L'.') {\r
      switch (*(FileName + 1)) {\r
      case L'\0':\r
        *FileName = L'\0';\r
        break;\r
      case L'\\':\r
        TempFileName = FileName + 1;\r
        TempFileName = ExcludeTrailingBackslashes (TempFileName);\r
        ReplaceLeft (FileName, TempFileName);\r
        break;\r
      case '.':\r
        if ((*(FileName - 1) != L'\\') && ((*(FileName + 2) != L'\\') ||\r
                                           (*(FileName + 2) != L'\0'))) {\r
          FileName++;\r
          continue;\r
        }\r
\r
        BackslashesNo = 0;\r
        TempFileName = FileName - 1;\r
        while (TempFileName >= FileNameSavedPointer) {\r
          if (*TempFileName == L'\\') {\r
            if (++BackslashesNo == 2) {\r
              break;\r
            }\r
          }\r
\r
          TempFileName--;\r
        }\r
\r
        TempFileName++;\r
\r
        if ((*TempFileName == L'.') && (*(TempFileName + 1) == L'.')) {\r
          FileName += 2;\r
        } else {\r
          if (*(FileName + 2) != L'\0') {\r
            ReplaceLeft (TempFileName, FileName + 3);\r
            if (*(TempFileName - 1) == L'\\') {\r
              FileName = TempFileName;\r
              ExcludeTrailingBackslashes (TempFileName - 1);\r
              TempFileName = FileName;\r
            }\r
          } else {\r
            *TempFileName = L'\0';\r
          }\r
\r
          FileName = TempFileName;\r
        }\r
\r
        break;\r
      default:\r
        FileName++;\r
      }\r
    } else {\r
      FileName++;\r
    }\r
  }\r
\r
  FileName = FileNameSavedPointer;\r
  if ((StrLen (FileName) > 1) && (FileName [StrLen (FileName) - 1] == L'\\')) {\r
    FileName [StrLen (FileName) - 1] = L'\0';\r
  }\r
\r
Exit:\r
  return FileName;\r
}\r