Script to compare file size of one file - powershell

Question

I am trying to write a script that tell me if a file file size is greater than a number, below is the script I have written, but it keeps showing 1999 even though I know the file size is greater than the number.
#echo off
setlocal enabledelayedexpansion
for /f "delims=" %%a in (' powershell -c "(Get-ChildItem -Recurse "C:\XSTOREDB\xstore_data.mdf" | Measure-Object -Property Length -Sum).Sum" ') do set "foldsize=%%a"
if "!foldsize!" GTR "6000000000" (
exit /B 0
) else (
exit /B 1999
)
endlocal

Answer 1

I'm pretty sure you have 2 problems. The first problem is that you are doing an alphabetical comparison. Thus, "7" would be considered GTR "6000000000".
Your second problem is that numeric operations in cmd are limited to 32 bit integers. The maximum number you can use is 2^31 - 1, which is 2147483647, which is already less than the number you are interested in.
The typical workaround here is to either compare the "important" parts of the string, or truncate the N least significant digits.
Here is a quick example. It may contain issues/errors in implementation. I did echo exit /b so the script would run and you can see the results instead of actual exit /b.
#echo off
setlocal enabledelayedexpansion
rem first we will inspect the 10th and 11th digits from the right
set foldsize=7000000010
rem If there is any number in the 11th spot, then it must be greater
if not "!foldsize:~0,-10!"=="" (
rem the number is at least 10000000000 which is greater so we exit
echo exit /B 0
)
rem check if the 10th digit is 6 or greater
rem add a zero to avoid issues with an undefined variable
set smallfoldsize=!foldsize:~0,-9!
if !smallfoldsize!0 GTR 50 (
rem technically the number is now greater or equal to 6000000000
rem I will leave it up to you if you really need it to be greater than
echo exit /B 0
) else (
rem it is smaller
echo exit /B 1999
)
rem an alternative is to discard the N least significant digits
rem I am stripping the last 7 digits and then adding a zero to avoid
rem an undefined variable
set smallfoldsize=!foldsize:~0,-7!0
if !smallfoldsize! GEQ 6000 (
echo exit /B 0
) else (
echo exit /B 1999
)
rem again, this is actual greater or equal. If you
rem need greater than, you have to look at the less
rem significant digits when smallfoldsize = 6000

Answer 2

avery_larry's helpful answer does a great job of explaining the fundamental problems with your approach (lexical rather than numerical comparison, numbers that are too large).
If your comparison doesn't need to be accurate down to the byte level, you can try the following approach, which enables a simpler solution:
Make PowerShell return a value in mebibytes (MiB) rather than bytes.
This should return a small enough number that you can compare (numerically) with cmd's GTR operator.
#echo off
setlocal enabledelayedexpansion
for /f "delims=" %%a in ('
powershell -noprofile -c ^
"[math]::Ceiling((Get-ChildItem -File -Recurse \"C:\XSTOREDB\xstore_data.mdf\" | Measure-Object -Property Length -Sum).Sum / 1mb)"
') do set "foldsize=%%a"
:: # 6000000000 bytes is ca. 5722 MB
if !foldsize! GTR 5722 (
exit /B 0
) else (
exit /B 1999
)
Note how the PowerShell command divides the result by 1mb (1 MiB (mebibyte) = 2 ^ 20 = 1,048,576 bytes) and then rounds it up via [math]::Ceiling()
Also note how the embedded " chars. were escaped as \" to ensure that PowerShell sees them.
Finally, note how, as a small optimization, -File was passed to the Get-ChildItem cmdlet in order to skip directories (themselves, not their files), given that directories themselves have no Length property.

Answer 3

Despite your question body, text, and title, not matching the code you have supplied, I do not see any need for a for-loop for this task.
Based upon your question body text, and title, to exit with an errorlevel of 0 if file C:\XSTOREDB\xstore_data.mdf is greater than 6GB:
#"%__AppDir__%WindowsPowerShell\v1.0\powershell.exe" -NoP "If(Test-Path -L "C:\XSTOREDB\xstore_data.mdf"){(GI -L "C:\XSTOREDB\xstore_data.mdf").Length -GT 6GB}" 2>NUL|"%__AppDir__%find.exe" "T">NUL&&(Exit /B 0)||Exit /B 1999
Based upon your question code, to exit with an errorlevel of 0 if directory C:\XSTOREDB totals more than 6GB:
#"%__AppDir__%WindowsPowerShell\v1.0\powershell.exe" -NoP "If(Test-Path -L "C:\XSTOREDB"){(GCI "C:\XSTOREDB" -Rec|Measure Length -Su -EA Stop).Sum -GT 6GB}" 2>NUL|"%__AppDir__%find.exe" "T">NUL&&(Exit /B 0)||Exit /B 1999