/** @file
  Main file for ls shell level 2 function.

  (C) Copyright 2013-2015 Hewlett-Packard Development Company, L.P.<BR>
  Copyright (c) 2009 - 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
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include "UefiShellLevel2CommandsLib.h"
#include <Guid/FileSystemInfo.h>

UINTN     mDayOfMonth[] = {31, 28, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30};

/**
  print out the standard format output volume entry.

  @param[in] TheList           a list of files from the volume.
**/
EFI_STATUS
PrintSfoVolumeInfoTableEntry(
  IN CONST EFI_SHELL_FILE_INFO *TheList
  )
{
  EFI_STATUS            Status;
  EFI_SHELL_FILE_INFO   *Node;
  CHAR16                *DirectoryName;
  EFI_FILE_SYSTEM_INFO  *SysInfo;
  UINTN                 SysInfoSize;
  SHELL_FILE_HANDLE     ShellFileHandle;
  EFI_FILE_PROTOCOL     *EfiFpHandle;

  //
  // Get the first valid handle (directories)
  //
  for ( Node = (EFI_SHELL_FILE_INFO *)GetFirstNode(&TheList->Link)
      ; !IsNull(&TheList->Link, &Node->Link) && Node->Handle == NULL
      ; Node = (EFI_SHELL_FILE_INFO *)GetNextNode(&TheList->Link, &Node->Link)
     );

  if (Node->Handle == NULL) {
    DirectoryName = GetFullyQualifiedPath(((EFI_SHELL_FILE_INFO *)GetFirstNode(&TheList->Link))->FullName);

    //
    // We need to open something up to get system information
    //
    Status = gEfiShellProtocol->OpenFileByName(
      DirectoryName,
      &ShellFileHandle,
      EFI_FILE_MODE_READ
      );

    ASSERT_EFI_ERROR(Status);
    FreePool(DirectoryName);

    //
    // Get the Volume Info from ShellFileHandle
    //
    SysInfo     = NULL;
    SysInfoSize = 0;
    EfiFpHandle = ConvertShellHandleToEfiFileProtocol(ShellFileHandle);
    Status = EfiFpHandle->GetInfo(
      EfiFpHandle,
      &gEfiFileSystemInfoGuid,
      &SysInfoSize,
      SysInfo
      );

    if (Status == EFI_BUFFER_TOO_SMALL) {
      SysInfo = AllocateZeroPool(SysInfoSize);
      Status = EfiFpHandle->GetInfo(
        EfiFpHandle,
        &gEfiFileSystemInfoGuid,
        &SysInfoSize,
        SysInfo
        );
    }

    ASSERT_EFI_ERROR(Status);

    gEfiShellProtocol->CloseFile(ShellFileHandle);
  } else {
    //
    // Get the Volume Info from Node->Handle
    //
    SysInfo = NULL;
    SysInfoSize = 0;
    EfiFpHandle = ConvertShellHandleToEfiFileProtocol(Node->Handle);
    Status = EfiFpHandle->GetInfo(
      EfiFpHandle,
      &gEfiFileSystemInfoGuid,
      &SysInfoSize,
      SysInfo
      );

    if (Status == EFI_BUFFER_TOO_SMALL) {
      SysInfo = AllocateZeroPool(SysInfoSize);
      Status = EfiFpHandle->GetInfo(
        EfiFpHandle,
        &gEfiFileSystemInfoGuid,
        &SysInfoSize,
        SysInfo
        );
    }

    ASSERT_EFI_ERROR(Status);
  }

  ShellPrintHiiEx (
    -1,
    -1,
    NULL,
    STRING_TOKEN (STR_GEN_SFO_HEADER),
    gShellLevel2HiiHandle,
    L"ls"
    );
  //
  // print VolumeInfo table
  //
  ASSERT(SysInfo != NULL);
  ShellPrintHiiEx (
    0,
    gST->ConOut->Mode->CursorRow,
    NULL,
    STRING_TOKEN (STR_LS_SFO_VOLINFO),
    gShellLevel2HiiHandle,
    SysInfo->VolumeLabel,
    SysInfo->VolumeSize,
    SysInfo->ReadOnly?L"TRUE":L"FALSE",
    SysInfo->FreeSpace,
    SysInfo->BlockSize
    );

  SHELL_FREE_NON_NULL(SysInfo);

  return (Status);
}

/**
  print out the info on a single file.

  @param[in] Sfo      TRUE if in SFO, false otherwise.
  @param[in] TheNode  the EFI_SHELL_FILE_INFO node to print out information on.
  @param[in] Files    incremented if a file is printed.
  @param[in] Size     incremented by file size.
  @param[in] Dirs     incremented if a directory is printed.

**/
VOID
PrintFileInformation(
  IN CONST BOOLEAN              Sfo,
  IN CONST EFI_SHELL_FILE_INFO  *TheNode,
  IN UINT64                     *Files,
  IN UINT64                     *Size,
  IN UINT64                     *Dirs
  )
{
  ASSERT(Files    != NULL);
  ASSERT(Size     != NULL);
  ASSERT(Dirs     != NULL);
  ASSERT(TheNode  != NULL);

  if (Sfo) {
    //
    // Print the FileInfo Table
    //
    ShellPrintHiiEx (
      0,
      gST->ConOut->Mode->CursorRow,
      NULL,
      STRING_TOKEN (STR_LS_SFO_FILEINFO),
      gShellLevel2HiiHandle,
      TheNode->FullName,
      TheNode->Info->FileSize,
      TheNode->Info->PhysicalSize,
      (TheNode->Info->Attribute & EFI_FILE_ARCHIVE)   != 0?L"a":L"",
      (TheNode->Info->Attribute & EFI_FILE_DIRECTORY) != 0?L"d":L"",
      (TheNode->Info->Attribute & EFI_FILE_HIDDEN)    != 0?L"h":L"",
      (TheNode->Info->Attribute & EFI_FILE_READ_ONLY) != 0?L"r":L"",
      (TheNode->Info->Attribute & EFI_FILE_SYSTEM)    != 0?L"s":L"",
      TheNode->Info->CreateTime.Hour,
      TheNode->Info->CreateTime.Minute,
      TheNode->Info->CreateTime.Second,
      TheNode->Info->CreateTime.Day,
      TheNode->Info->CreateTime.Month,
      TheNode->Info->CreateTime.Year,
      TheNode->Info->LastAccessTime.Hour,
      TheNode->Info->LastAccessTime.Minute,
      TheNode->Info->LastAccessTime.Second,
      TheNode->Info->LastAccessTime.Day,
      TheNode->Info->LastAccessTime.Month,
      TheNode->Info->LastAccessTime.Year,
      TheNode->Info->ModificationTime.Hour,
      TheNode->Info->ModificationTime.Minute,
      TheNode->Info->ModificationTime.Second,
      TheNode->Info->ModificationTime.Day,
      TheNode->Info->ModificationTime.Month,
      TheNode->Info->ModificationTime.Year
      );
  } else {
    //
    // print this one out...
    // first print the universal start, next print the type specific name format, last print the CRLF
    //
    ShellPrintHiiEx (
      -1,
      -1,
      NULL,
      STRING_TOKEN (STR_LS_LINE_START_ALL),
      gShellLevel2HiiHandle,
      &TheNode->Info->ModificationTime,
      (TheNode->Info->Attribute & EFI_FILE_DIRECTORY) != 0?L"<DIR>":L"",
      (TheNode->Info->Attribute & EFI_FILE_READ_ONLY) != 0?L'r':L' ',
      TheNode->Info->FileSize
      );
    if (TheNode->Info->Attribute & EFI_FILE_DIRECTORY) {
      (*Dirs)++;
      ShellPrintHiiEx (
        -1,
        -1,
        NULL,
        STRING_TOKEN (STR_LS_LINE_END_DIR),
        gShellLevel2HiiHandle,
        TheNode->FileName
        );
    } else {
      (*Files)++;
      (*Size) += TheNode->Info->FileSize;
      if ( (gUnicodeCollation->StriColl(gUnicodeCollation, (CHAR16*)L".nsh", (CHAR16*)&(TheNode->FileName[StrLen (TheNode->FileName) - 4])) == 0)
        || (gUnicodeCollation->StriColl(gUnicodeCollation, (CHAR16*)L".efi", (CHAR16*)&(TheNode->FileName[StrLen (TheNode->FileName) - 4])) == 0)
       ){
        ShellPrintHiiEx (
          -1,
          -1,
          NULL,
          STRING_TOKEN (STR_LS_LINE_END_EXE),
          gShellLevel2HiiHandle,
          TheNode->FileName
          );
      } else {
        ShellPrintHiiEx (
          -1,
          -1,
          NULL,
          STRING_TOKEN (STR_LS_LINE_END_FILE),
          gShellLevel2HiiHandle,
          TheNode->FileName
          );
      }
    }
  }
}

/**
  print out the header when not using standard format output.

  @param[in] Path           String with starting path.
**/
VOID
PrintNonSfoHeader(
  IN CONST CHAR16 *Path
  )
{
  CHAR16 *DirectoryName;

  //
  // get directory name from path...
  //
  DirectoryName = GetFullyQualifiedPath(Path);

  if (DirectoryName != NULL) {
    //
    // print header
    //
    ShellPrintHiiEx (
      0,
      gST->ConOut->Mode->CursorRow,
      NULL,
      STRING_TOKEN (STR_LS_HEADER_LINE1),
      gShellLevel2HiiHandle,
      DirectoryName
      );

    SHELL_FREE_NON_NULL(DirectoryName);
  }
}

/**
  print out the footer when not using standard format output.

  @param[in] Files            The number of files.
  @param[in] Size             The size of files in bytes.
  @param[in] Dirs             The number of directories.
**/
VOID
PrintNonSfoFooter(
  IN UINT64                     Files,
  IN UINT64                     Size,
  IN UINT64                     Dirs
  )
{
  //
  // print footer
  //
  ShellPrintHiiEx (
    -1,
    -1,
    NULL,
    STRING_TOKEN (STR_LS_FOOTER_LINE),
    gShellLevel2HiiHandle,
    Files,
    Size,
    Dirs
   );
}

/**
  Change the file time to local time based on the timezone.

  @param[in] Time               The file time.
  @param[in] LocalTimeZone      Local time zone.
**/
VOID
FileTimeToLocalTime (
  IN EFI_TIME             *Time,
  IN INT16                LocalTimeZone
  )
{
  INTN                    MinuteDiff;
  INTN                    TempMinute;
  INTN                    HourNumberOfTempMinute;
  INTN                    TempHour;
  INTN                    DayNumberOfTempHour;
  INTN                    TempDay;
  INTN                    MonthNumberOfTempDay;
  INTN                    TempMonth;
  INTN                    YearNumberOfTempMonth;
  INTN                    MonthRecord;

  ASSERT ((Time->TimeZone >= -1440) && (Time->TimeZone <=1440));
  ASSERT ((LocalTimeZone >= -1440) && (LocalTimeZone <=1440));
  ASSERT ((Time->Month >= 1) && (Time->Month <= 12));

  if(Time->TimeZone == LocalTimeZone) {
    //
    //if the file timezone is equal to the local timezone, there is no need to adjust the file time.
    //
    return;
  }

  if((Time->Year % 4 == 0 && Time->Year / 100 != 0)||(Time->Year % 400 == 0)) {
    //
    // Day in February of leap year is 29.
    //
    mDayOfMonth[1] = 29;
  }

  MinuteDiff = Time->TimeZone - LocalTimeZone;
  TempMinute = Time->Minute + MinuteDiff;

  //
  // Calculate Time->Minute
  // TempHour will be used to calculate Time->Hour
  //
  HourNumberOfTempMinute = TempMinute / 60;
  if(TempMinute < 0) {
    HourNumberOfTempMinute --;
  }
  TempHour = Time->Hour + HourNumberOfTempMinute;
  Time->Minute = (UINT8)(TempMinute - 60 * HourNumberOfTempMinute);

  //
  // Calculate Time->Hour
  // TempDay will be used to calculate Time->Day
  //
  DayNumberOfTempHour = TempHour / 24 ;
  if(TempHour < 0){
    DayNumberOfTempHour--;
  }
  TempDay = Time->Day + DayNumberOfTempHour;
  Time->Hour = (UINT8)(TempHour - 24 * DayNumberOfTempHour);

  //
  // Calculate Time->Day
  // TempMonth will be used to calculate Time->Month
  //
  MonthNumberOfTempDay = (TempDay - 1) / (INTN)mDayOfMonth[Time->Month - 1];
  MonthRecord = (INTN)(Time->Month) ;
  if(TempDay - 1 < 0){
    MonthNumberOfTempDay -- ;
    MonthRecord -- ;
  }
  TempMonth = Time->Month + MonthNumberOfTempDay;
  Time->Day = (UINT8)(TempDay - (INTN)mDayOfMonth[(MonthRecord - 1 + 12) % 12] * MonthNumberOfTempDay);

  //
  // Calculate Time->Month, Time->Year
  //
  YearNumberOfTempMonth = (TempMonth - 1) / 12;
  if(TempMonth - 1 < 0){
    YearNumberOfTempMonth --;
  }
  Time->Month = (UINT8)(TempMonth - 12 * (YearNumberOfTempMonth));
  Time->Year = (UINT16)(Time->Year + YearNumberOfTempMonth);
}

/**
  print out the list of files and directories from the LS command

  @param[in] Rec            TRUE to automatically recurse into each found directory
                            FALSE to only list the specified directory.
  @param[in] Attribs        List of required Attribute for display.
                            If 0 then all non-system and non-hidden files will be printed.
  @param[in] Sfo            TRUE to use Standard Format Output, FALSE otherwise
  @param[in] RootPath       String with starting path to search in.
  @param[in] SearchString   String with search string.
  @param[in] Found          Set to TRUE, if anyone were found.
  @param[in] Count          The count of bits enabled in Attribs.
  @param[in] TimeZone       The current time zone offset.

  @retval SHELL_SUCCESS     the printing was sucessful.
**/
SHELL_STATUS
PrintLsOutput(
  IN CONST BOOLEAN Rec,
  IN CONST UINT64  Attribs,
  IN CONST BOOLEAN Sfo,
  IN CONST CHAR16  *RootPath,
  IN CONST CHAR16  *SearchString,
  IN       BOOLEAN *Found,
  IN CONST UINTN   Count,
  IN CONST INT16   TimeZone
  )
{
  EFI_STATUS            Status;
  EFI_SHELL_FILE_INFO   *ListHead;
  EFI_SHELL_FILE_INFO   *Node;
  SHELL_STATUS          ShellStatus;
  UINT64                FileCount;
  UINT64                DirCount;
  UINT64                FileSize;
  UINTN                 LongestPath;
  CHAR16                *CorrectedPath;
  BOOLEAN               FoundOne;
  BOOLEAN               HeaderPrinted;
  EFI_TIME              LocalTime;

  HeaderPrinted = FALSE;
  FileCount     = 0;
  DirCount      = 0;
  FileSize      = 0;
  ListHead      = NULL;
  ShellStatus   = SHELL_SUCCESS;
  LongestPath   = 0;
  CorrectedPath = NULL;

  if (Found != NULL) {
    FoundOne = *Found;
  } else {
    FoundOne = FALSE;
  }

  CorrectedPath = StrnCatGrow(&CorrectedPath, &LongestPath, RootPath,     0);
  if (CorrectedPath == NULL) {
    return SHELL_OUT_OF_RESOURCES;
  }
  if (CorrectedPath[StrLen(CorrectedPath)-1] != L'\\'
    &&CorrectedPath[StrLen(CorrectedPath)-1] != L'/') {
    CorrectedPath = StrnCatGrow(&CorrectedPath, &LongestPath, L"\\",     0);
  }
  CorrectedPath = StrnCatGrow(&CorrectedPath, &LongestPath, SearchString, 0);
  if (CorrectedPath == NULL) {
    return (SHELL_OUT_OF_RESOURCES);
  }

  PathCleanUpDirectories(CorrectedPath);

  Status = ShellOpenFileMetaArg((CHAR16*)CorrectedPath, EFI_FILE_MODE_READ, &ListHead);
  if (!EFI_ERROR(Status)) {
    if (ListHead == NULL || IsListEmpty(&ListHead->Link)) {
      SHELL_FREE_NON_NULL(CorrectedPath);
      return (SHELL_SUCCESS);
    }

    if (Sfo && Found == NULL) {
      PrintSfoVolumeInfoTableEntry(ListHead);
    }

    for ( Node = (EFI_SHELL_FILE_INFO *)GetFirstNode(&ListHead->Link), LongestPath = 0
        ; !IsNull(&ListHead->Link, &Node->Link)
        ; Node = (EFI_SHELL_FILE_INFO *)GetNextNode(&ListHead->Link, &Node->Link)
        ){
      if (ShellGetExecutionBreakFlag ()) {
        ShellStatus = SHELL_ABORTED;
        break;
      }
      ASSERT(Node != NULL);

      //
      // Change the file time to local time.
      //
      Status = gRT->GetTime(&LocalTime, NULL);
      if (!EFI_ERROR (Status)) {
        if ((Node->Info->CreateTime.TimeZone != EFI_UNSPECIFIED_TIMEZONE) &&
            (Node->Info->CreateTime.Month >= 1 && Node->Info->CreateTime.Month <= 12)) {
          //
          // FileTimeToLocalTime () requires Month is in a valid range, other buffer out-of-band access happens.
          //
          FileTimeToLocalTime (&Node->Info->CreateTime, LocalTime.TimeZone);
        }
        if ((Node->Info->LastAccessTime.TimeZone != EFI_UNSPECIFIED_TIMEZONE) &&
            (Node->Info->LastAccessTime.Month >= 1 && Node->Info->LastAccessTime.Month <= 12)) {
          FileTimeToLocalTime (&Node->Info->LastAccessTime, LocalTime.TimeZone);
        }
        if ((Node->Info->ModificationTime.TimeZone != EFI_UNSPECIFIED_TIMEZONE) &&
            (Node->Info->ModificationTime.Month >= 1 && Node->Info->ModificationTime.Month <= 12)) {
          FileTimeToLocalTime (&Node->Info->ModificationTime, LocalTime.TimeZone);
        }
      }

      if (LongestPath < StrSize(Node->FullName)) {
        LongestPath = StrSize(Node->FullName);
      }
      ASSERT(Node->Info != NULL);
      ASSERT((Node->Info->Attribute & EFI_FILE_VALID_ATTR) == Node->Info->Attribute);
      if (Attribs == 0) {
        //
        // NOT system & NOT hidden
        //
        if ( (Node->Info->Attribute & EFI_FILE_SYSTEM)
          || (Node->Info->Attribute & EFI_FILE_HIDDEN)
         ){
          continue;
        }
      } else if ((Attribs != EFI_FILE_VALID_ATTR) ||
                 (Count == 5)) {
        //
        // Only matches the bits which "Attribs" contains, not
        // all files/directories with any of the bits.
        // Count == 5 is used to tell the difference between a user
        // specifying all bits (EX: -arhsda) and just specifying
        // -a (means display all files with any attribute).
        //
        if ( (Node->Info->Attribute & Attribs) != Attribs) {
          continue;
        }
      }

      if (!Sfo && !HeaderPrinted) {
        PathRemoveLastItem (CorrectedPath);
        PrintNonSfoHeader(CorrectedPath);
      }
      PrintFileInformation(Sfo, Node, &FileCount, &FileSize, &DirCount);
      FoundOne = TRUE;
      HeaderPrinted = TRUE;
    }

    if (!Sfo && ShellStatus != SHELL_ABORTED) {
      PrintNonSfoFooter(FileCount, FileSize, DirCount);
    }
  }

  if (Rec && ShellStatus != SHELL_ABORTED) {
    //
    // Re-Open all the files under the starting path for directories that didnt necessarily match our file filter
    //
    ShellCloseFileMetaArg(&ListHead);
    CorrectedPath[0] = CHAR_NULL;
    CorrectedPath = StrnCatGrow(&CorrectedPath, &LongestPath, RootPath, 0);
    if (CorrectedPath == NULL) {
      return SHELL_OUT_OF_RESOURCES;
    }
    if (CorrectedPath[StrLen(CorrectedPath)-1] != L'\\'
      &&CorrectedPath[StrLen(CorrectedPath)-1] != L'/') {
      CorrectedPath = StrnCatGrow(&CorrectedPath, &LongestPath, L"\\",     0);
    }
    CorrectedPath = StrnCatGrow(&CorrectedPath, &LongestPath, L"*",     0);
    Status = ShellOpenFileMetaArg((CHAR16*)CorrectedPath, EFI_FILE_MODE_READ, &ListHead);

    if (!EFI_ERROR(Status)) {
      for ( Node = (EFI_SHELL_FILE_INFO *)GetFirstNode(&ListHead->Link)
          ; !IsNull(&ListHead->Link, &Node->Link) && ShellStatus == SHELL_SUCCESS
          ; Node = (EFI_SHELL_FILE_INFO *)GetNextNode(&ListHead->Link, &Node->Link)
         ){
        if (ShellGetExecutionBreakFlag ()) {
          ShellStatus = SHELL_ABORTED;
          break;
        }

        //
        // recurse on any directory except the traversing ones...
        //
        if (((Node->Info->Attribute & EFI_FILE_DIRECTORY) == EFI_FILE_DIRECTORY)
          && StrCmp(Node->FileName, L".") != 0
          && StrCmp(Node->FileName, L"..") != 0
         ){
          ShellStatus = PrintLsOutput(
            Rec,
            Attribs,
            Sfo,
            Node->FullName,
            SearchString,
            &FoundOne,
            Count,
            TimeZone);

          //
          // Since it's running recursively, we have to break immediately when returned SHELL_ABORTED
          //
          if (ShellStatus == SHELL_ABORTED) {
            break;
          }
        }
      }
    }
  }

  SHELL_FREE_NON_NULL(CorrectedPath);
  ShellCloseFileMetaArg(&ListHead);

  if (Found == NULL && !FoundOne) {
    return (SHELL_NOT_FOUND);
  }

  if (Found != NULL) {
    *Found = FoundOne;
  }

  return (ShellStatus);
}

STATIC CONST SHELL_PARAM_ITEM LsParamList[] = {
  {L"-r", TypeFlag},
  {L"-a", TypeStart},
  {L"-sfo", TypeFlag},
  {NULL, TypeMax}
  };

/**
  Function for 'ls' command.

  @param[in] ImageHandle  Handle to the Image (NULL if Internal).
  @param[in] SystemTable  Pointer to the System Table (NULL if Internal).
**/
SHELL_STATUS
EFIAPI
ShellCommandRunLs (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS    Status;
  LIST_ENTRY    *Package;
  CHAR16        *ProblemParam;
  CONST CHAR16  *Attribs;
  SHELL_STATUS  ShellStatus;
  UINT64        RequiredAttributes;
  CONST CHAR16  *PathName;
  CONST CHAR16  *CurDir;
  UINTN         Count;
  CHAR16        *FullPath;
  UINTN         Size;
  EFI_TIME      TheTime;
  CHAR16        *SearchString;

  Size                = 0;
  FullPath            = NULL;
  ProblemParam        = NULL;
  Attribs             = NULL;
  ShellStatus         = SHELL_SUCCESS;
  RequiredAttributes  = 0;
  PathName            = NULL;
  SearchString        = NULL;
  CurDir              = NULL;
  Count               = 0;

  //
  // initialize the shell lib (we must be in non-auto-init...)
  //
  Status = ShellInitialize();
  ASSERT_EFI_ERROR(Status);

  //
  // Fix local copies of the protocol pointers
  //
  Status = CommandInit();
  ASSERT_EFI_ERROR(Status);

  //
  // parse the command line
  //
  Status = ShellCommandLineParse (LsParamList, &Package, &ProblemParam, TRUE);
  if (EFI_ERROR(Status)) {
    if (Status == EFI_VOLUME_CORRUPTED && ProblemParam != NULL) {
      ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_PROBLEM), gShellLevel2HiiHandle, L"ls", ProblemParam);
      FreePool(ProblemParam);
      ShellStatus = SHELL_INVALID_PARAMETER;
    } else {
      ASSERT(FALSE);
    }
  } else {
    //
    // check for "-?"
    //
    if (ShellCommandLineGetFlag(Package, L"-?")) {
      ASSERT(FALSE);
    }

    if (ShellCommandLineGetCount(Package) > 2) {
      ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_TOO_MANY), gShellLevel2HiiHandle, L"ls");
      ShellStatus = SHELL_INVALID_PARAMETER;
    } else {
      //
      // check for -a
      //
      if (ShellCommandLineGetFlag(Package, L"-a")) {
        for ( Attribs = ShellCommandLineGetValue(Package, L"-a")
            ; Attribs != NULL && *Attribs != CHAR_NULL && ShellStatus == SHELL_SUCCESS
            ; Attribs++
           ){
          switch (*Attribs) {
            case L'a':
            case L'A':
              RequiredAttributes |= EFI_FILE_ARCHIVE;
              Count++;
              continue;
            case L's':
            case L'S':
              RequiredAttributes |= EFI_FILE_SYSTEM;
              Count++;
              continue;
            case L'h':
            case L'H':
              RequiredAttributes |= EFI_FILE_HIDDEN;
              Count++;
              continue;
            case L'r':
            case L'R':
              RequiredAttributes |= EFI_FILE_READ_ONLY;
              Count++;
              continue;
            case L'd':
            case L'D':
              RequiredAttributes |= EFI_FILE_DIRECTORY;
              Count++;
              continue;
            default:
              ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_ATTRIBUTE), gShellLevel2HiiHandle, L"ls", ShellCommandLineGetValue(Package, L"-a"));
              ShellStatus = SHELL_INVALID_PARAMETER;
              break;
          } // switch
        } // for loop
        //
        // if nothing is specified all are specified
        //
        if (RequiredAttributes == 0) {
          RequiredAttributes = EFI_FILE_VALID_ATTR;
        }
      } // if -a present
      if (ShellStatus == SHELL_SUCCESS) {
        PathName = ShellCommandLineGetRawValue(Package, 1);
        if (PathName == NULL) {
          //
          // Nothing specified... must start from current directory
          //
          CurDir = gEfiShellProtocol->GetCurDir(NULL);
          if (CurDir == NULL) {
            ShellStatus = SHELL_NOT_FOUND;
            ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_NO_CWD), gShellLevel2HiiHandle, L"ls");
          }
          //
          // Copy to the 2 strings for starting path and file search string
          //
          ASSERT(SearchString == NULL);
          ASSERT(FullPath == NULL);
          StrnCatGrow(&SearchString, NULL, L"*", 0);
          StrnCatGrow(&FullPath, NULL, CurDir, 0);
          Size = FullPath != NULL? StrSize(FullPath) : 0;
          StrnCatGrow(&FullPath, &Size, L"\\", 0);
        } else {
          if (StrStr(PathName, L":") == NULL && gEfiShellProtocol->GetCurDir(NULL) == NULL) {
            //
            // If we got something and it doesnt have a fully qualified path, then we needed to have a CWD.
            //
            ShellStatus = SHELL_NOT_FOUND;
            ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_NO_CWD), gShellLevel2HiiHandle, L"ls");
          } else {
            //
            // We got a valid fully qualified path or we have a CWD
            //
            ASSERT((FullPath == NULL && Size == 0) || (FullPath != NULL));
            if (StrStr(PathName, L":") == NULL) {
              StrnCatGrow(&FullPath, &Size, gEfiShellProtocol->GetCurDir(NULL), 0);
              if (FullPath == NULL) {
                ShellCommandLineFreeVarList (Package);
                return SHELL_OUT_OF_RESOURCES;
              }
              Size = FullPath != NULL? StrSize(FullPath) : 0;
              StrnCatGrow(&FullPath, &Size, L"\\", 0);
            }
            StrnCatGrow(&FullPath, &Size, PathName, 0);
            if (FullPath == NULL) {
                ShellCommandLineFreeVarList (Package);
                return SHELL_OUT_OF_RESOURCES;
            }

            if  (ShellIsDirectory(PathName) == EFI_SUCCESS) {
              //
              // is listing ends with a directory, then we list all files in that directory
              //
              StrnCatGrow(&SearchString, NULL, L"*", 0);
            } else {
              //
              // must split off the search part that applies to files from the end of the directory part
              //
              StrnCatGrow(&SearchString, NULL, FullPath, 0);
              if (SearchString == NULL) {
                FreePool (FullPath);
                ShellCommandLineFreeVarList (Package);
                return SHELL_OUT_OF_RESOURCES;
              }
              PathRemoveLastItem (FullPath);
              CopyMem (SearchString, SearchString + StrLen (FullPath), StrSize (SearchString + StrLen (FullPath)));
            }
          }
        }
        Status = gRT->GetTime(&TheTime, NULL);
        if (EFI_ERROR(Status)) {
          ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_UEFI_FUNC_WARN), gShellLevel2HiiHandle, L"ls", L"gRT->GetTime", Status);
          TheTime.TimeZone = EFI_UNSPECIFIED_TIMEZONE;
        }

        if (ShellStatus == SHELL_SUCCESS) {
          ShellStatus = PrintLsOutput(
            ShellCommandLineGetFlag(Package, L"-r"),
            RequiredAttributes,
            ShellCommandLineGetFlag(Package, L"-sfo"),
            FullPath,
            SearchString,
            NULL,
            Count,
            TheTime.TimeZone
           );
          if (ShellStatus == SHELL_NOT_FOUND) {
            ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_LS_FILE_NOT_FOUND), gShellLevel2HiiHandle, L"ls", FullPath);
          } else if (ShellStatus == SHELL_INVALID_PARAMETER) {
            ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_PARAM_INV), gShellLevel2HiiHandle, L"ls", FullPath);
          } else if (ShellStatus == SHELL_ABORTED) {
            //
            // Ignore aborting.
            //
          } else if (ShellStatus != SHELL_SUCCESS) {
            ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_PARAM_INV), gShellLevel2HiiHandle, L"ls", FullPath);
          }
        }
      }
    }
  }

  //
  // Free memory allocated
  //
  SHELL_FREE_NON_NULL(SearchString);
  SHELL_FREE_NON_NULL(FullPath);
  ShellCommandLineFreeVarList (Package);

  return (ShellStatus);
}