@echo off

REM Name: showmemusage.bat
REM Created: November 25, 2014
REM Last Modified: November 25, 2014
REM Version: 1.0
REM
REM Description: calculates the total amount of memory used by all instances
REM of a specified process name. The name can be placed on the command line,
REM e.g., "showmemusage chrome.exe". If none is included on the command line,
REM i.e., the batch file is run with "showmemusage", it will prompt for a
REM process name. The total memory usage derived from the tasklist command
REM will be displayed in kilobytes (KB). See
REM http://support.moonpoint.com/os/windows/commands/batch/showmemusage.php

setlocal EnableDelayedExpansion
set total=0

REM If no process name was entered on the command line, prompt for the process
REM name.
IF [%1]==[] (
   set /p pname="Process name: "
) ELSE (
   set pname=%1
)

for /f "tokens=5" %%i in ('tasklist /fi "imagename eq %pname%" ^| findstr " K$"
') do (
   set pmemuse=%%i
   REM eliminate the comma from the number
   set pmemuse=!pmemuse:,=!
   set /a total=!total! + !pmemuse!
)
echo %total% K