Refine comments and two code style.

[mirror_edk2.git] / ShellPkg / Library / BasePathLib / BasePathLib.c

/** @file\r
  Provides interface to path manipulation functions.\r
\r
  Copyright (c) 2011, Intel Corporation. All rights reserved.<BR>\r
  This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this 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,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
**/\r
\r
#include <Base.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/PathLib.h>\r
#include <Library/BaseLib.h>\r
\r
/**\r
  Removes the last directory or file entry in a path by changing the last\r
  L'\' to a CHAR_NULL.\r
\r
  @param[in, out] Path    The 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
    }\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
  @retval NULL          An error occured.\r
  @return Path in all other instances.\r
**/\r
CHAR16*\r
EFIAPI\r
PathCleanUpDirectories(\r
  IN CHAR16 *Path\r
  )\r
{\r
  CHAR16  *TempString;\r
  UINTN   TempSize;\r
  if (Path==NULL) {\r
    return(NULL);\r
  }\r
\r
  //\r
  // Fix up the '/' vs '\'\r
  //\r
  for (TempString = Path ; TempString != NULL && *TempString != CHAR_NULL ; TempString++) {\r
    if (*TempString == L'/') {\r
      *TempString = L'\\';\r
    }\r
  }\r
\r
  //\r
  // Fix up the ..\r
  //\r
  while ((TempString = StrStr(Path, L"\\..\\")) != NULL) {\r
    *TempString = CHAR_NULL;\r
    TempString  += 4;\r
    PathRemoveLastItem(Path);\r
    TempSize = StrSize(TempString);\r
    CopyMem(Path+StrLen(Path), TempString, TempSize);\r
  }\r
  if ((TempString = StrStr(Path, L"\\..")) != NULL && *(TempString + 3) == CHAR_NULL) {\r
    *TempString = CHAR_NULL;\r
    PathRemoveLastItem(Path);\r
  }\r
\r
  //\r
  // Fix up the .\r
  //\r
  while ((TempString = StrStr(Path, L"\\.\\")) != NULL) {\r
    *TempString = CHAR_NULL;\r
    TempString  += 2;\r
    TempSize = StrSize(TempString);\r
    CopyMem(Path+StrLen(Path), TempString, TempSize);\r
  }\r
  if ((TempString = StrStr(Path, L"\\.")) != NULL && *(TempString + 2) == CHAR_NULL) {\r
    *TempString = CHAR_NULL;\r
  }\r
\r
\r
\r
  return (Path);\r
}\r
\r