Assignment inside a if block is not working

Question

I need to read a data from registry, add 1 to it and then rewrite the data back in registry

FOR /f "tokens=2*" %%a in ('reg query "HKLM\SOFTWARE\Looptest" /v "subcounter"') do set "subcounter=%%b"

if %subcounter% EQU 6 (
    set /a counter=%counter%+1
    echo increasing value for counter %counter% >> abc.log
    reg add HKLM\Software\Looptest /f /v counter /t REG_SZ /d %counter%
    pause
)

But,the problem in this code is that, it does not increase the data of COUNTER. Any explanation ?

Thanks !

you need [delayed expansion](http://ss64.com/nt/delayedexpansion.html) — npocmaka, Oct 12 '16 at 14:20
Possible duplicate of [Variable doesn't get updated in the function of Batch file](http://stackoverflow.com/questions/31832215/variable-doesnt-get-updated-in-the-function-of-batch-file) — aschipfl, Oct 12 '16 at 16:30

score 2 · Accepted Answer · answered Oct 12 '16 at 16:18

Specifically...

@echo off & setlocal enabledelayedexpansion
FOR /f "tokens=2*" %%a in ('reg query "HKLM\SOFTWARE\Looptest" /v "subcounter"') do set "counter=%%b"

if %counter% EQU 6 (
    set /a counter+=1
    echo increasing value for counter !counter! >> abc.log
    reg add HKLM\Software\Looptest /f /v counter /t REG_SZ /d !counter!
)

Alternatively, use CALL, and double %%.

@echo off
FOR /f "tokens=2*" %%a in ('reg query "HKLM\SOFTWARE\Looptest" /v "subcounter"') do set "counter=%%b"

if %counter% EQU 6 (
    set /a counter+=1
    call echo increasing value for counter %%counter%% >> abc.log
    call reg add HKLM\Software\Looptest /f /v counter /t REG_SZ /d %%counter%%
)

Assignment inside a if block is not working

1 Answers1