IF… OR IF… in a windows batch file

2019-01-04 11:09发布

Is there a way to write an IF OR IF conditional statement in a windows batch-file?

For example:

IF [%var%] == [1] OR IF [%var%] == [2] ECHO TRUE

13条回答
地球回转人心会变
2楼-- · 2019-01-04 11:16

The goal can be achieved by using IFs indirectly.

Below is an example of a complex expression that can be written quite concisely and logically in a CMD batch, without incoherent labels and GOTOs.

Code blocks between () brackets are handled by CMD as a (pathetic) kind of subshell. Whatever exit code comes out of a block will be used to determine the true/false value the block plays in a larger boolean expression. Arbitrarily large boolean expressions can be built with these code blocks.

Simple example

Each block is resolved to true (i.e. ERRORLEVEL = 0 after the last statement in the block has executed) / false, until the value of the whole expression has been determined or control jumps out (e.g. via GOTO):

 ((DIR c:\xsgdde /w) || (DIR c:\ /w)) && (ECHO -=BINGO=-)

Complex example

This solves the problem raised initially. Multiple statements are possible in each block but in the || || || expression it's preferable to be concise so that it's as readable as possible. ^ is an escape char in CMD batches and when placed at the end of a line it will escape the EOL and instruct CMD to continue reading the current batch of statements on the next line.

@ECHO OFF
SETLOCAL ENABLEDELAYEDEXPANSION

(
    (CALL :ProcedureType1 a b) ^
        || (CALL :ProcedureType2 sgd) ^
            || (CALL :ProcedureType1 c c)
) ^
    && (
        ECHO -=BINGO=-
        GOTO :EOF
    )
ECHO -=no bingo for you=-
GOTO :EOF

:ProcedureType1
    IF "%~1" == "%~2" (EXIT /B 0) ELSE (EXIT /B 1)
GOTO :EOF (this line is decorative as it's never reached)

:ProcedureType2
    ECHO :ax:xa:xx:aa:|FINDSTR /I /L /C:":%~1:">nul
GOTO :EOF
查看更多
该账号已被封号
3楼-- · 2019-01-04 11:19
If %x%==1 (
If %y%==1 (
:: both are equal to 1.
)
)

That's for checking if multiple variables equal value. Here's for either variable.

If %x%==1 (
:: true
)
If %x%==0 (
If %y%==1 (
:: true
)
)
If %x%==0 (
If %y%==0 (
:: False
)
)

I just thought of that off the top if my head. I could compact it more.

查看更多
该账号已被封号
4楼-- · 2019-01-04 11:22

It's possible to use a function, which evaluates the OR logic and returns a single value.

@echo off
set var1=3
set var2=5
call :logic_or orResult "'%var1%'=='4'" "'%var2%'=='5'"
if %orResult%==1 ( 
    echo At least one expression is true
) ELSE echo All expressions are false
exit /b

:logic_or <resultVar> expression1 [[expr2] ... expr-n] 
SETLOCAL
set "logic_or.result=0"
set "logic_or.resultVar=%~1"

:logic_or_loop 
if "%~2"=="" goto :logic_or_end 
if %~2 set "logic_or.result=1"
SHIFT 
goto :logic_or_loop 

:logic_or_end 
( 
  ENDLOCAL 
  set "%logic_or.resultVar%=%logic_or.result%"
  exit /b
) 
查看更多
走好不送
5楼-- · 2019-01-04 11:23

I realize this question is old, but I wanted to post an alternate solution in case anyone else (like myself) found this thread while having the same question. I was able to work around the lack of an OR operator by echoing the variable and using findstr to validate.

for /f %%v in ('echo %var% ^| findstr /x /c:"1" /c:"2"') do (
    if %errorlevel% equ 0 echo true
)
查看更多
兄弟一词,经得起流年.
6楼-- · 2019-01-04 11:24

Thanks for this post, it helped me a lot.

Dunno if it can help but I had the issue and thanks to you I found what I think is another way to solve it based on this boolean equivalence:

"A or B" is the same as "not(not A and not B)"

Thus:

IF [%var%] == [1] OR IF [%var%] == [2] ECHO TRUE

Becomes:

IF not [%var%] == [1] IF not [%var%] == [2] ECHO FALSE
查看更多
相关推荐>>
7楼-- · 2019-01-04 11:26

There is no IF <arg> OR or ELIF or ELSE IF in Batch, however...

Try nesting the other IF's inside the ELSE of the previous IF.

IF <arg> (
    ....
) ELSE (
    IF <arg> (
        ......
    ) ELSE (
        IF <arg> (
            ....
        ) ELSE (
    )
)
查看更多
登录 后发表回答