1 /** @file
2 Defines file-path manipulation functions.
3
4 Copyright (c) 2011 - 2016, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php.
9
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12 **/
13 #include <Library/BaseMemoryLib.h>
14 #include <Library/BaseLib.h>
15
16 /**
17 Removes the last directory or file entry in a path. For a path which is
18 like L"fs0:startup.nsh", it's converted to L"fs0:".
19
20 @param[in,out] Path A pointer to the path to modify.
21
22 @retval FALSE Nothing was found to remove.
23 @retval TRUE A directory or file was removed.
24 **/
25 BOOLEAN
26 EFIAPI
PathRemoveLastItem(IN OUT CHAR16 * Path)27 PathRemoveLastItem(
28 IN OUT CHAR16 *Path
29 )
30 {
31 CHAR16 *Walker;
32 CHAR16 *LastSlash;
33 //
34 // get directory name from path... ('chop' off extra)
35 //
36 for ( Walker = Path, LastSlash = NULL
37 ; Walker != NULL && *Walker != CHAR_NULL
38 ; Walker++
39 ){
40 if (*Walker == L'\\' && *(Walker + 1) != CHAR_NULL) {
41 LastSlash = Walker+1;
42 } else if (*Walker == L':' && *(Walker + 1) != L'\\' && *(Walker + 1) != CHAR_NULL) {
43 LastSlash = Walker+1;
44 }
45 }
46 if (LastSlash != NULL) {
47 *LastSlash = CHAR_NULL;
48 return (TRUE);
49 }
50 return (FALSE);
51 }
52
53 /**
54 Function to clean up paths.
55
56 - Single periods in the path are removed.
57 - Double periods in the path are removed along with a single parent directory.
58 - Forward slashes L'/' are converted to backward slashes L'\'.
59
60 This will be done inline and the existing buffer may be larger than required
61 upon completion.
62
63 @param[in] Path The pointer to the string containing the path.
64
65 @return Returns Path, otherwise returns NULL to indicate that an error has occured.
66 **/
67 CHAR16*
68 EFIAPI
PathCleanUpDirectories(IN CHAR16 * Path)69 PathCleanUpDirectories(
70 IN CHAR16 *Path
71 )
72 {
73 CHAR16 *TempString;
74
75 if (Path == NULL) {
76 return NULL;
77 }
78
79 //
80 // Replace the '/' with '\'
81 //
82 for (TempString = Path; *TempString != CHAR_NULL; TempString++) {
83 if (*TempString == L'/') {
84 *TempString = L'\\';
85 }
86 }
87
88 //
89 // Remove all the "\.". E.g.: fs0:\abc\.\def\.
90 //
91 while ((TempString = StrStr (Path, L"\\.\\")) != NULL) {
92 CopyMem (TempString, TempString + 2, StrSize (TempString + 2));
93 }
94 if (StrCmp (Path + StrLen (Path) - 2, L"\\.") == 0) {
95 Path[StrLen (Path) - 1] = CHAR_NULL;
96 }
97
98 //
99 // Remove all the "\..". E.g.: fs0:\abc\..\def\..
100 //
101 while (((TempString = StrStr(Path, L"\\..")) != NULL) &&
102 ((*(TempString + 3) == L'\\') || (*(TempString + 3) == CHAR_NULL))
103 ) {
104 *(TempString + 1) = CHAR_NULL;
105 PathRemoveLastItem(Path);
106 CopyMem (Path + StrLen (Path), TempString + 3, StrSize (TempString + 3));
107 }
108
109 //
110 // Replace the "\\" with "\"
111 //
112 while ((TempString = StrStr (Path, L"\\\\")) != NULL) {
113 CopyMem (TempString, TempString + 1, StrSize (TempString + 1));
114 }
115
116 return Path;
117 }
118
119