[PATCH 1/2] ShellPkg-Shell App: Provide fully-qualified path to shell scripts

[<Jim.Dailey@dell.com>]

Add a function to return the fully-qualified version of some path.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jim Dailey <jim_dailey@dell.com>
---
 ShellPkg/Include/Library/ShellLib.h          | 40 +++++++++
 ShellPkg/Library/UefiShellLib/UefiShellLib.c | 93 +++++++++++++++++++-
 2 files changed, 132 insertions(+), 1 deletion(-)

diff --git a/ShellPkg/Include/Library/ShellLib.h b/ShellPkg/Include/Library/ShellLib.h
index 92fddc50f5..cd7e9c47c3 100644
--- a/ShellPkg/Include/Library/ShellLib.h
+++ b/ShellPkg/Include/Library/ShellLib.h
@@ -2,6 +2,7 @@
   Provides interface to shell functionality for shell commands and applications.
 
   Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright 2018 Dell Technologies.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
@@ -35,6 +36,45 @@
 extern EFI_SHELL_PARAMETERS_PROTOCOL *gEfiShellParametersProtocol;
 extern EFI_SHELL_PROTOCOL            *gEfiShellProtocol;
 
+/**
+  Return the fully-qualified version of a relative path or an absolute path that
+  does not include a file system reference.
+
+  If ASSERTs are disabled, and if the input parameter is NULL or points to NULL,
+  then NULL is returned.
+
+  If the input path contains a ":", this function assumes that it is part of a
+  reference to a file system (e.g. "FS0:").  In such a case, Path is cleaned
+  and returned.
+
+  If there is no working directory or there is not enough memory available to
+  create the fully-qualified path, Path is cleaned and returned.
+
+  Otherwise, the current file system or working directory (as appropriate) is
+  prepended to Path.  The input Path is freed and the resulting path is cleaned,
+  assigned to Path, and returned.
+
+  NOTE: If the input path is an empty string, then the current working directory
+  (if it exists) is returned.  In other words, an empty input path is treated
+  exactly the same as ".".
+
+  @param[in, out] Path  On input, a pointer to some file or directory path.  On
+                        output, a pointer to the clean and possibly fully-
+                        qualified version of the input path.  The input pointer
+                        may be freed and reassigned on output.
+
+  @retval NULL          The input pointer or the path itself was NULL.
+
+  @return A pointer to the clean, fully-qualified version of Path.  If memory
+          allocation fails, or if there is no working directory, then a pointer
+          to the clean, but not necessarily fully-qualified version of Path.
+**/
+CHAR16*
+EFIAPI
+FullyQualifyPath(
+  IN OUT CHAR16     **Path
+  );
+
 /**
   This function will retrieve the information about the file for the handle
   specified and store it in allocated pool memory.
diff --git a/ShellPkg/Library/UefiShellLib/UefiShellLib.c b/ShellPkg/Library/UefiShellLib/UefiShellLib.c
index f04adbb63f..52ca3ce1b1 100644
--- 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.
 
   (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
-  Copyright 2016 Dell Inc.
+  Copyright 2016-2018 Dell Technologies.<BR>
   Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
@@ -36,6 +36,97 @@ EFI_HANDLE                    mEfiShellEnvironment2Handle;
 FILE_HANDLE_FUNCTION_MAP      FileFunctionMap;
 EFI_UNICODE_COLLATION_PROTOCOL  *mUnicodeCollationProtocol;
 
+/**
+  Return the fully-qualified version of a relative path or an absolute path that
+  does not include a file system reference.
+
+  If asserts are disabled, and if the input parameter is NULL or points to NULL,
+  then NULL is returned.
+
+  If the input path contains a ":", this function assumes that it is part of a
+  reference to a file system (e.g. "FS0:").  In such a case, Path is cleaned
+  and returned.
+
+  If there is no working directory or there is not enough memory available to
+  create the fully-qualified path, Path is cleaned and returned.
+
+  Otherwise, the current file system or working directory (as appropriate) is
+  prepended to Path.  The input Path is freed and the resulting path is cleaned,
+  assigned to Path, and returned.
+
+  NOTE: If the input path is an empty string, then the current working directory
+  (if it exists) is returned.  In other words, an empty input path is treated
+  exactly the same as ".".
+
+  @param[in, out] Path  On input, a pointer to some file or directory path.  On
+                        output, a pointer to the clean and possibly fully-
+                        qualified version of the input path.  The input pointer
+                        may be freed and reassigned on output.
+
+  @retval NULL          The input pointer or the path itself was NULL.
+
+  @return A pointer to the clean, fully-qualified version of Path.  If memory
+          allocation fails, or if there is no working directory, then a pointer
+          to the clean, but not necessarily fully-qualified version of Path.
+**/
+CHAR16*
+EFIAPI
+FullyQualifyPath(
+  IN OUT    CHAR16     **Path
+  )
+{
+  CONST CHAR16         *WorkingPath;
+  CHAR16               *FullyQualifiedPath;
+  UINTN                Size;
+
+  ASSERT(Path != NULL);
+  ASSERT(*Path != NULL);
+
+  //
+  // Handle erroneous input when asserts are disabled.
+  //
+  if (Path == NULL || *Path == NULL) {
+    return NULL;
+  }
+
+  if (StrStr(*Path, L":") == NULL) {
+    WorkingPath = ShellGetEnvironmentVariable(L"cwd");
+    if (WorkingPath != NULL) {
+      //
+      // Room for both strings plus one more character.
+      //
+      Size = StrSize(WorkingPath) + StrSize(*Path);
+      FullyQualifiedPath = AllocateZeroPool(Size);
+      if (FullyQualifiedPath != NULL) {
+        if (**Path == L'\\' || **Path == L'/') {
+          //
+          // Absolute path: start with the current working directory, then
+          // truncate the new path after the file system part.
+          //
+          StrCpyS(FullyQualifiedPath, Size/sizeof(CHAR16), WorkingPath);
+          *(StrStr(FullyQualifiedPath, L":") + 1) = CHAR_NULL;
+        } else {
+          //
+          // Relative path: start with the working directory and append "\".
+          //
+          StrCpyS(FullyQualifiedPath, Size/sizeof(CHAR16), WorkingPath);
+          StrCatS(FullyQualifiedPath, Size/sizeof(CHAR16), L"\\");
+        }
+        //
+        // Now append the absolute or relative path.
+        //
+        StrCatS(FullyQualifiedPath, Size/sizeof(CHAR16), *Path);
+        FreePool(*Path);
+        *Path = FullyQualifiedPath;
+      }
+    }
+  }
+
+  PathCleanUpDirectories(*Path);
+
+  return *Path;
+}
+
 /**
   Check if a Unicode character is a hexadecimal character.
 
-- 
2.17.0.windows.1