MdePkg: Replace BSD License with BSD+Patent License

[mirror_edk2.git] / MdePkg / Library / BaseLib / FilePaths.c

/** @file\r
  Defines file-path manipulation functions.\r
\r
  Copyright (c) 2011 - 2017, Intel Corporation. All rights reserved.<BR>\r
  Copyright (c) 2018, Dell Technologies. All rights reserved.<BR>\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
**/\r
#include  <Library/BaseMemoryLib.h>\r
#include  <Library/BaseLib.h>\r
\r
/**\r
  Removes the last directory or file entry in a path. For a path which is\r
  like L"fs0:startup.nsh", it's converted to L"fs0:".\r
\r
  @param[in,out] Path     A pointer to the path to modify.\r
\r
  @retval FALSE     Nothing was found to remove.\r
  @retval TRUE      A directory or file was removed.\r
**/\r
BOOLEAN\r
EFIAPI\r
PathRemoveLastItem(\r
  IN OUT CHAR16 *Path\r
  )\r
{\r
  CHAR16        *Walker;\r
  CHAR16        *LastSlash;\r
  //\r
  // get directory name from path... ('chop' off extra)\r
  //\r
  for ( Walker = Path, LastSlash = NULL\r
      ; Walker != NULL && *Walker != CHAR_NULL\r
      ; Walker++\r
     ){\r
    if (*Walker == L'\\' && *(Walker + 1) != CHAR_NULL) {\r
      LastSlash = Walker+1;\r
    } else if (*Walker == L':' && *(Walker + 1) != L'\\' && *(Walker + 1) != CHAR_NULL) {\r
      LastSlash = Walker+1;\r
    }\r
  }\r
  if (LastSlash != NULL) {\r
    *LastSlash = CHAR_NULL;\r
    return (TRUE);\r
  }\r
  return (FALSE);\r
}\r
\r
/**\r
  Function to clean up paths.\r
\r
  - Single periods in the path are removed.\r
  - Double periods in the path are removed along with a single parent directory.\r
  - Forward slashes L'/' are converted to backward slashes L'\'.\r
\r
  This will be done inline and the existing buffer may be larger than required\r
  upon completion.\r
\r
  @param[in] Path       The pointer to the string containing the path.\r
\r
  @return       Returns Path, otherwise returns NULL to indicate that an error has occured.\r
**/\r
CHAR16*\r
EFIAPI\r
PathCleanUpDirectories(\r
  IN CHAR16 *Path\r
)\r
{\r
  CHAR16  *TempString;\r
\r
  if (Path == NULL) {\r
    return NULL;\r
  }\r
\r
  //\r
  // Replace the '/' with '\'\r
  //\r
  for (TempString = Path; *TempString != CHAR_NULL; TempString++) {\r
    if (*TempString == L'/') {\r
      *TempString = L'\\';\r
    }\r
  }\r
\r
  //\r
  // Replace the "\\" with "\"\r
  //\r
  while ((TempString = StrStr (Path, L"\\\\")) != NULL) {\r
    CopyMem (TempString, TempString + 1, StrSize (TempString + 1));\r
  }\r
\r
  //\r
  // Remove all the "\.". E.g.: fs0:\abc\.\def\.\r
  //\r
  while ((TempString = StrStr (Path, L"\\.\\")) != NULL) {\r
    CopyMem (TempString, TempString + 2, StrSize (TempString + 2));\r
  }\r
  if ((StrLen (Path) >= 2) && (StrCmp (Path + StrLen (Path) - 2, L"\\.") == 0)) {\r
    Path[StrLen (Path) - 1] = CHAR_NULL;\r
  }\r
\r
  //\r
  // Remove all the "\..". E.g.: fs0:\abc\..\def\..\r
  //\r
  while (((TempString = StrStr(Path, L"\\..")) != NULL) &&\r
         ((*(TempString + 3) == L'\\') || (*(TempString + 3) == CHAR_NULL))\r
        ) {\r
    *(TempString + 1) = CHAR_NULL;\r
    PathRemoveLastItem(Path);\r
    if (*(TempString + 3) != CHAR_NULL) {\r
      CopyMem (Path + StrLen (Path), TempString + 4, StrSize (TempString + 4));\r
    }\r
  }\r
\r
  return Path;\r
}\r
\r