Function: LargeInt_cmp

Compares decimal numbers.

@echo off
:loop
set/p ch= give 2 numbers one after another : 
for /f "tokens=1,2" %%G in ("%ch%") do (set left=%%G&set right=%%H)
call:LargeInt_cmp left right
if "%errorlevel%"=="0" (echo  Left is greater.)
if "%errorlevel%"=="1" (echo  Equal to each other.)
if "%errorlevel%"=="2" (echo  Right is greater.)
if "%errorlevel%"=="3" (echo  Invalid input.)
echo.
goto loop
:LargeInt_cmp
::returns
::
:: ERRORLEVEL
:: 0 = left is greater
:: 1 = equal
:: 2 = right is greater
:: 3 = invalid input
::
setlocal
set v0=%% %1 %%
set v0=%v0: =%
call set left=%v0%
set v0=%% %2 %%
set v0=%v0: =%
call set right=%v0%
if not defined left (endlocal&&exit/b3)
if not defined right (endlocal&&exit/b3)
call:IsInteger left||endlocal&&exit/b3
call:IsInteger right||endlocal&&exit/b3
set left_IsNegative=false
set right_IsNegative=false
if "%left:~0,1%"=="-" (set left_IsNegative=true)
if "%right:~0,1%"=="-" (set right_IsNegative=true)
set cond_gtr=GTR
set cond_lss=LSS
if "%left_IsNegative%"=="true" (
 if "%right_IsNegative%"=="false" (
  goto right_is_greater
 )
)
if "%left_IsNegative%"=="false" (
 if "%right_IsNegative%"=="true" (
  goto left_is_greater
 )
)
if "%left_IsNegative%"=="true" (
 if "%right_IsNegative%"=="true" (
  set cond_gtr=LSS
  set cond_lss=GTR
 )
)
call:strlen %left%
set sizeof_left=%errorlevel%
call:strlen %right%
set sizeof_right=%errorlevel%
if %sizeof_left% %cond_gtr% %sizeof_right% (
 :left_is_greater
 endlocal&exit/b0
)
if %sizeof_left% %cond_lss% %sizeof_right% (
 :right_is_greater
 endlocal&exit/b2
)
:wigloop
set left_tmp=%left:~0,1%
set right_tmp=%right:~0,1%
set left=%left:~1%
set right=%right:~1%
if %left_tmp% %cond_gtr% %right_tmp% (goto left_is_greater)
if %right_tmp% %cond_gtr% %left_tmp% (goto right_is_greater)
if defined left (goto wigloop)
endlocal&exit/b1

:strlen
setlocal
set param=%1
if not defined param (set length=0&goto strlen_end)
:strlen_0
set param=%param:~0,-1%
set/a length+=1
if defined param (goto strlen_0)
endlocal&exit/b%length%

:IsInteger
call:IsHex %1 10&&exit/b0||exit/b1
:IsHex
setlocal
set var=%% %1 %%
set var=%var: =%
call set var=%var%
if "%2"=="10" (if "%var:~0,1%"=="-" (set var=%var:~1%)) else (if "%var:~0,2%"=="0x" (set var=%var:~2%))
set IsHex=0
set var=%var:0= %
set var=%var:1= %
set var=%var:2= %
set var=%var:3= %
set var=%var:4= %
set var=%var:5= %
set var=%var:6= %
set var=%var:7= %
set var=%var:8= %
set var=%var:9= %
if "%2"=="10" (goto ishex_)
set var=%var:A= %
set var=%var:B= %
set var=%var:C= %
set var=%var:D= %
set var=%var:E= %
set var=%var:F= %
:ishex_
set var=%var: =%
if defined var (set IsHex=1)
endlocal&exit/b%IsHex%