|In your IF statement, your "outputvar" needs to be a variable (yours is a string-constant whose value is outputvar, and it needs quotes around it unless they're supplied from the line from temp.txt. You may need to enable|
delayedexpansion, but probably not.
SO, it should look something like this:
IF "!outputvar!" equ "" (
You can't use percents (%outputvar%), because you're inside a code-block. You might be able to skip the whole issue like this:
for /f "delims=" %%f in ('dir /b *.jpg') do (
for /f "tokens=*" %%a in ('exiftool -GPSDateStamp "%%f" ^&^& echo gps positive ^|^| echo gps negative') do (
if "%%a" equ "gps positive" (
) else (
Which would eliminate both the temp file and the outputvar in one throw, but it all depends on whether exiftool sets errorlevel or not.