How to get file size of included files automatically

Hi,

we have an installer to install a hardware driver on several windows platforms.

We were asked to provide an option to just extract ALL driver files.
A check should be included to make sure that there is enough free disk space at the destination.

I was searching quite a bit, but did not find something like DLLVersionLocal for GetFilesizeLocal.

So I came up with the following:

# Unixtools from  http://unxutils.sourceforge.net/
!define DRIVERS "${PROJECTDIR}driver"
!define EFS_INCLUDE "${PROJECTDIR}driver\DrvExtrSize.nsh"
                                
!SYSTEM '(echo.|set /p =!define EXTRACTFILESIZE ) >${EFS_INCLUDE}'
!SYSTEM '${UNIXTOOL}\du -s -k ${DRIVERS}| ${UNIXTOOL}\cut -f1 >>${EFS_INCLUDE}'
!include ${EFS_INCLUDE}
:
:
:
Section Extract XTR     
    AddSize ${EXTRACTFILESIZE}
SectionEnd 

This will create an include file with a define for the filesize at compile time and can be later used for comparison with the free disk space.

If there's a smarter solution I'd be glad to learn.