Format a hexadecimal sequence in a cmd.exe batch file

问题

In a Windows cmd script (aka bat script), I have a FOR /L loop from 1 to 8, where I need to do a bit shift and somehow format a variable as a hexadecimal number (which if you ask, is a single CPU identifier bit to feed into /AFFINITY).

I can't figure out how to do the last step. This is my loop.cmd file:

@ECHO OFF
SETLOCAL ENABLEDELAYEDEXPANSION
FOR /L %%i IN (1,1,8) DO (
    SET /A "J=1<<%%i"
    ECHO %%i and !J!
)

which does everything but format a hex number:

1 and 2
2 and 4
3 and 8
4 and 16
5 and 32
6 and 64
7 and 128
8 and 256

expected output is:

1 and 2
2 and 4
3 and 8
4 and 10
5 and 20
6 and 40
7 and 80
8 and 100

How do you format a hexadecimal number?

回答1:

@ECHO OFF
SETLOCAL ENABLEDELAYEDEXPANSION
FOR /L %%i IN (1,1,8) DO (
    SET /A "J=1<<%%i"
    CALL :DECTOHEX J
    ECHO %%i and !J!
)
GOTO :EOF

:DECTOHEX VAR
SET "DEC=!%1!"
SET "HEX="
:NEXT
    SET /A DIGIT=DEC%%16, DEC/=16
    SET "HEX=%DIGIT%%HEX%"
IF %DEC% NEQ 0 GOTO NEXT
SET "%1=%HEX%"
EXIT /B

EDIT: Reply to the comment

Previous solution works correctly when the shifted value have just one bit on, as stated in the question. If the shifted value may have several bits on then a more general decimal-to-hexadecimal conversion is required, like the one below:

@ECHO OFF
SETLOCAL ENABLEDELAYEDEXPANSION

REM DEFINE THE HEXA DIGITS
SET "HEXA=0123456789ABCDEF"

FOR /L %%i IN (1,1,8) DO (
    SET /A "J=3<<%%i"
    CALL :DECTOHEX J
    ECHO %%i and !J!
)
GOTO :EOF

:DECTOHEX VAR
SET "DEC=!%1!"
SET "HEX="
:NEXT
    SET /A DIGIT=DEC%%16, DEC/=16
    SET "HEX=!HEXA:~%DIGIT%,1!%HEX%"
IF %DEC% NEQ 0 GOTO NEXT
SET "%1=%HEX%"
EXIT /B

回答2:

@echo off
setlocal enabledelayedexpansion
set x=2
set n=1
set /a result=n
for /l %%a in (1,1,10) do (
  set /a result*=x
  if "!result:~0,1!"=="1" set result=!result:16=10!
  echo %%a and !result!
)

output:

1 and 2
2 and 4
3 and 8
4 and 10
5 and 20
6 and 40
7 and 80
8 and 100
9 and 200
10 and 400

来源：https://stackoverflow.com/questions/32961479/format-a-hexadecimal-sequence-in-a-cmd-exe-batch-file

标签

batch-file

for-loop

cmd

hex

string-formatting