BATCH SET unable to use divide operator

batchbatch file

I am unable to divide using the divide operator provided in the SET command.

SET /A 216/18

SET /A div=216/18

ECHO %div%

Though this should work and it does in the command prompt window but when used through a batch script it gives a blank output.

ECHO is on.

Whats wrong?

Best Answer

This can happen if your extenstions are disabled. You can check setlocal /? and cmd /? for more information about extensions.

But the set /? specifies:

If Command Extensions are enabled SET changes as follows:  
...
Two new switches have been added to the SET command:  
  SET /A expression  
  SET /P variable=[promptString]

So without extensions the /A does not work.

You can add the setlocal-line to the top of your batchfile:

setlocal enableextensions enabledelayedexpansion
SET /A 216/18
SET /A div=216/18
ECHO %div%

Related Solutions

Windows Batch Script for getting disk space details

Double the % sign denoting loop control variables: %a to %%a, %b to %%b and so on:

@ECHO OFF
SETLOCAL enableextensions
(for /f "tokens=1-3" %%a in ('
  WMIC LOGICALDISK GET FreeSpace^,Name^,Size ^|FINDSTR /I /V "Name"
  ') do (
    echo wsh.echo "%%b" ^& " free=" ^& FormatNumber^(cdbl^(%%a^)/1024/1024/1024, 2^)^& " GB"^& " size=" ^& FormatNumber^(cdbl^(%%c^)/1024/1024/1024, 2^)^& " GB" > "%temp%\tmp.vbs"
    if not "%%c"=="" (
      echo( 
      cscript //nologo "%temp%\tmp.vbs"
      del "%temp%\tmp.vbs"
    )
  )
) > E:\monitoring_scripts\log\Disk_status.txt

or, with less disk writes to the %temp% folder and with the only cscript call:

@ECHO OFF
SETLOCAL enableextensions
(for /f "tokens=1-3" %%a in ('
  WMIC LOGICALDISK GET FreeSpace^,Name^,Size ^|FINDSTR /I /V "Name"
  ') do (
    if not "%%c"=="" (
      echo wsh.echo vbNewLine ^& "%%b" ^& " free=" ^& FormatNumber^(cdbl^(%%a^)/1024/1024/1024, 2^)^& " GB"^& " size=" ^& FormatNumber^(cdbl^(%%c^)/1024/1024/1024, 2^)^& " GB"
    )
  )
) > "%temp%\tmp.vbs"
cscript //nologo "%temp%\tmp.vbs" > E:\monitoring_scripts\log\Disk_status.txt
del "%temp%\tmp.vbs"

Resources (further reading): An A-Z Index of the Windows CMD command line

Best Answer

Related Solutions

Windows Batch Script for getting disk space details

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