ShellPkg-UefiShellLib: Add a function to fully-qualify paths

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

diff --git a/ShellPkg/Library/UefiShellLib/UefiShellLib.c b/ShellPkg/Library/UefiShellLib/UefiShellLib.c
index f04adbb63ffe650a9a0b77b06d5e324a57dbcc4b..580a1ee612d6c641d0e310b2ad7e630a5ad73732 100644 (file)
--- a/ShellPkg/Library/UefiShellLib/UefiShellLib.c
+++ b/ShellPkg/Library/UefiShellLib/UefiShellLib.c
@@ -2,7 +2,7 @@
   Provides interface to shell functionality for shell commands and applications.\r
 \r
   (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>\r
-  Copyright 2016 Dell Inc.\r
+  Copyright 2016-2018 Dell Technologies.<BR>\r
   Copyright (c) 2006 - 2018, 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
@@ -36,6 +36,121 @@ EFI_HANDLE                    mEfiShellEnvironment2Handle;
 FILE_HANDLE_FUNCTION_MAP      FileFunctionMap;\r
 EFI_UNICODE_COLLATION_PROTOCOL  *mUnicodeCollationProtocol;\r
 \r
+/**\r
+  Return a clean, fully-qualified version of an input path.  If the return value\r
+  is non-NULL the caller must free the memory when it is no longer needed.\r
+\r
+  If asserts are disabled, and if the input parameter is NULL, NULL is returned.\r
+\r
+  If there is not enough memory available to create the fully-qualified path or\r
+  a copy of the input path, NULL is returned.\r
+\r
+  If there is no working directory, a clean copy of Path is returned.\r
+\r
+  Otherwise, the current file system or working directory (as appropriate) is\r
+  prepended to Path and the resulting path is cleaned and returned.\r
+\r
+  NOTE: If the input path is an empty string, then the current working directory\r
+  (if it exists) is returned.  In other words, an empty input path is treated\r
+  exactly the same as ".".\r
+\r
+  @param[in] Path  A pointer to some file or directory path.\r
+\r
+  @retval NULL          The input path is NULL or out of memory.\r
+\r
+  @retval non-NULL      A pointer to a clean, fully-qualified version of Path.\r
+                        If there is no working directory, then a pointer to a\r
+                        clean, but not necessarily fully-qualified version of\r
+                        Path.  The caller must free this memory when it is no\r
+                        longer needed.\r
+**/\r
+CHAR16*\r
+EFIAPI\r
+FullyQualifyPath(\r
+  IN     CONST CHAR16     *Path\r
+  )\r
+{\r
+  CONST CHAR16         *WorkingPath;\r
+  CONST CHAR16         *InputPath;\r
+  CHAR16               *InputFileSystem;\r
+  UINTN                FileSystemCharCount;\r
+  CHAR16               *FullyQualifiedPath;\r
+  UINTN                Size;\r
+\r
+  FullyQualifiedPath = NULL;\r
+\r
+  ASSERT(Path != NULL);\r
+  //\r
+  // Handle erroneous input when asserts are disabled.\r
+  //\r
+  if (Path == NULL) {\r
+    return NULL;\r
+  }\r
+  //\r
+  // In paths that contain ":", like fs0:dir/file.ext and fs2:\fqpath\file.ext,\r
+  // we  have to consider the file system part separately from the "path" part.\r
+  // If there is a file system in the path, we have to get the current working\r
+  // directory for that file system. Then we need to use the part of the path\r
+  // following the ":".  If a path does not contain ":", we use it as given.\r
+  //\r
+  InputPath = StrStr(Path, L":");\r
+  if (InputPath != NULL) {\r
+    InputPath++;\r
+    FileSystemCharCount = ((UINTN)InputPath - (UINTN)Path + sizeof(CHAR16)) / sizeof(CHAR16);\r
+    InputFileSystem = AllocateCopyPool(FileSystemCharCount * sizeof(CHAR16), Path);\r
+    if (InputFileSystem != NULL) {\r
+      InputFileSystem[FileSystemCharCount - 1] = CHAR_NULL;\r
+    }\r
+    WorkingPath = ShellGetCurrentDir(InputFileSystem);\r
+    SHELL_FREE_NON_NULL(InputFileSystem);\r
+  } else {\r
+    InputPath = Path;\r
+    WorkingPath = ShellGetEnvironmentVariable(L"cwd");\r
+  }\r
+\r
+  if (WorkingPath == NULL) {\r
+    //\r
+    // With no working directory, all we can do is copy and clean the input path.\r
+    //\r
+    FullyQualifiedPath = AllocateCopyPool(StrSize(Path), Path);\r
+  } else {\r
+    //\r
+    // Allocate space for both strings plus one more character.\r
+    //\r
+    Size = StrSize(WorkingPath) + StrSize(InputPath);\r
+    FullyQualifiedPath = AllocateZeroPool(Size);\r
+    if (FullyQualifiedPath == NULL) {\r
+      //\r
+      // Try to copy and clean just the input. No harm if not enough memory.\r
+      //\r
+      FullyQualifiedPath = AllocateCopyPool(StrSize(Path), Path);\r
+    } else {\r
+      if (*InputPath == L'\\' || *InputPath == L'/') {\r
+        //\r
+        // Absolute path: start with the current working directory, then\r
+        // truncate the new path after the file system part.\r
+        //\r
+        StrCpyS(FullyQualifiedPath, Size/sizeof(CHAR16), WorkingPath);\r
+        *(StrStr(FullyQualifiedPath, L":") + 1) = CHAR_NULL;\r
+      } else {\r
+        //\r
+        // Relative path: start with the working directory and append "\".\r
+        //\r
+        StrCpyS(FullyQualifiedPath, Size/sizeof(CHAR16), WorkingPath);\r
+        StrCatS(FullyQualifiedPath, Size/sizeof(CHAR16), L"\\");\r
+      }\r
+      //\r
+      // Now append the absolute or relative path.\r
+      //\r
+      StrCatS(FullyQualifiedPath, Size/sizeof(CHAR16), InputPath);\r
+    }\r
+  }\r
+\r
+  PathCleanUpDirectories(FullyQualifiedPath);\r
+\r
+  return FullyQualifiedPath;\r
+}\r
+\r
 /**\r
   Check if a Unicode character is a hexadecimal character.\r
 \r