audk/MdePkg/Library/BaseLib/FilePaths.c

116 lines
3.0 KiB
C

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