Source code for add.bat

@ECHO OFF

SETLOCAL ENABLEEXTENSIONS

SETLOCAL ENABLEDELAYEDEXPANSION

SET _FIRST=%1

SET _SECOND=%2

CALL :ADD _FIRST _SECOND _ANSWER

ECHO !_ANSWER!

ENDLOCAL

ENDLOCAL

GOTO :END

:ADD

   ::ADD NUMBERS LARGER THAN 32-BITS

   ::SYNTAX: CALL ADD _VAR1 _VAR2 _VAR3

   ::VER 1.2

   ::hieyeque1@gmail.com - drop me a note telling me

   ::if this has helped you.  Sometimes I don't know if anyone uses my stuff

   ::Its free for the world to use.

   ::I retain the rights to it though, you may not copyright this

   ::to prevent others from using it, you may however copyright works

   ::as a whole that use this code.

   ::Just don't try to stop others from using this through some legal means.

   ::CopyRight Brian Williams 8/29/2009

   :: _VAR1 = VARIABLE FIRST NUMBER TO ADD

   :: _VAR2 = VARIABLE SECOND NUMBER TO ADD

   :: _VAR3 = VARIABLE NUMBER RETURNED

   SET _RESULT=

   SETLOCAL

   SET _NUM1=!%1!

   SET _NUM2=!%2!

   IF NOT DEFINED _NUM1 SET _NUM1=0

   IF NOT DEFINED _NUM2 SET _NUM2=0

   FOR /L %%A IN (1,1,2) DO (

      FOR /L %%B IN (0,1,9) DO (

         SET _NUM%%A=!_NUM%%A:%%B=%%B !

         )

      )

   FOR %%A IN (%_NUM1%) DO SET /A _NUM1CNT+=1 & SET _!_NUM1CNT!_NUM1=%%A

   FOR %%A IN (%_NUM2%) DO SET /A _NUM2CNT+=1 & SET _!_NUM2CNT!_NUM2=%%A

   SET _NUM1=%_NUM1: =%

   SET _NUM2=%_NUM2: =%

   SET /A _DIGITS=%_NUM1CNT% + %_NUM2CNT%

   IF %_DIGITS% LEQ 8 (

      SET /A _RESULT=%_NUM1% + %_NUM2%

      )

   IF DEFINED _RESULT (ENDLOCAL & SET %3=%_RESULT%& GOTO :EOF)

   IF %_NUM1CNT% GEQ %_NUM2CNT% (SET _MAXOPS=%_NUM1CNT%) ELSE (SET _MAXOPS=%_NUM2CNT%)

   SET /A _MAXOPS=%_MAXOPS% - 1

   IF %_NUM1CNT% GTR %_NUM2CNT% (

      SET /A _ZEROS=%_NUM1CNT% - %_NUM2CNT%

      FOR /L %%A IN (1,1,!_ZEROS!) DO SET _ZERO=!_ZERO!0

      SET _NUM2=!_ZERO!!_NUM2!

      )

   IF %_NUM2CNT% GTR %_NUM1CNT% (

      SET /A _ZEROS=%_NUM2CNT% - %_NUM1CNT%

      FOR /L %%A IN (1,1,!_ZEROS!) DO SET _ZERO=!_ZERO!0

      SET _NUM1=!_ZERO!!_NUM1!

      )

   FOR /L %%A IN (!_MAXOPS!,-1,0) DO (

      SET /A _TMP=!_NUM1:~%%A,1! + !_NUM2:~%%A,1! !_PLUS! !_CO!

      SET _CO=

      SET _PLUS=

      IF !_TMP! GTR 9 SET _CO=!_TMP:~0,1!& SET _TMP=!_TMP:~-1!& SET _PLUS=+

      SET _RETURN=!_TMP!!_RETURN!

      SET _TMP=

      )

   IF DEFINED _CO SET _RETURN=%_CO%%_RETURN%

   SET _RESULT=%_RETURN%

   IF DEFINED _RESULT (ENDLOCAL&SET %3=%_RESULT%)

   GOTO :EOF

:END