ShellPkg/ls: Display the file time in local time.

Signed-off-by: Li Huajing <huajing.li@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>

ShellPkg/Library/UefiShellLevel2CommandsLib/Ls.c

@@ -2,7 +2,7 @@
   Main file for ls shell level 2 function.
 
   (C) Copyright 2013-2015 Hewlett-Packard Development Company, L.P.<BR>
-  Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2009 - 2017, 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
@@ -16,6 +16,8 @@
 #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.
 
@@ -318,6 +320,96 @@ PrintNonSfoFooter(
    );
 }
 
+/**
+  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
 
@@ -357,6 +449,7 @@ PrintLsOutput(
   CHAR16                *CorrectedPath;
   BOOLEAN               FoundOne;
   BOOLEAN               HeaderPrinted;
+  EFI_TIME              LocalTime;
 
   HeaderPrinted = FALSE;
   FileCount     = 0;
@@ -408,6 +501,29 @@ PrintLsOutput(
         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);
       }