Function: BinToHex

Script snippet presented below exemplifies the usage. BinToHex "procedure" now works locally. Validity of the input is to be verified before passing it to the function. ERRORLEVEL is set to 1 if input is empty or if it encounters illegal character. Update: performance improved.

@echo off
:loop
echo.
set/p input= give binary number 
call:BinToHex input output
if "%errorlevel%"=="1" (echo  Conversion failed.) else (echo  [%input%] == [0x%output%])
goto loop
:BinToHex
setlocal
set var1=%% %1 %%
set var1=%var1: =%
call set var1=%var1%
:bintohex_lp
call:bintohex_ [%var1:~-4%]||goto bintohex_failure
set var0=%var2%%var0%&set var1=%var1:~0,-4%
if not defined var1 (goto bintohex_end) else (goto bintohex_lp)
:bintohex_
if "%1"=="[0000]" set var2=0&exit/b0
if "%1"=="[0001]" set var2=1&exit/b0
if "%1"=="[0010]" set var2=2&exit/b0
if "%1"=="[0011]" set var2=3&exit/b0
if "%1"=="[0100]" set var2=4&exit/b0
if "%1"=="[0101]" set var2=5&exit/b0
if "%1"=="[0110]" set var2=6&exit/b0
if "%1"=="[0111]" set var2=7&exit/b0
if "%1"=="[1000]" set var2=8&exit/b0
if "%1"=="[1001]" set var2=9&exit/b0
if "%1"=="[1010]" set var2=A&exit/b0
if "%1"=="[1011]" set var2=B&exit/b0
if "%1"=="[1100]" set var2=C&exit/b0
if "%1"=="[1101]" set var2=D&exit/b0
if "%1"=="[1110]" set var2=E&exit/b0
if "%1"=="[1111]" set var2=F&exit/b0
if "%1"=="[111]" set var2=7&exit/b0
if "%1"=="[110]" set var2=6&exit/b0
if "%1"=="[101]" set var2=5&exit/b0
if "%1"=="[100]" set var2=4&exit/b0
if "%1"=="[011]" set var2=3&exit/b0
if "%1"=="[010]" set var2=2&exit/b0
if "%1"=="[001]" set var2=1&exit/b0
if "%1"=="[000]" set var2=0&exit/b0
if "%1"=="[11]" set var2=3&exit/b0
if "%1"=="[10]" set var2=2&exit/b0
if "%1"=="[01]" set var2=1&exit/b0
if "%1"=="[00]" set var2=0&exit/b0
if "%1"=="[1]" set var2=1&exit/b0
if "%1"=="[0]" set var2=0&exit/b0
exit/b1
:bintohex_failure
set var0=&set temp_err=1
:bintohex_end
endlocal&set %2=%var0%&exit/b%temp_err%