How to expand an string to a charractere in batch?

Question

I have the file named: italo.jpeg

How to extract italo (before period) using:

set file=italo.jpeg
set prefix=%file:~[arguments]%

I've tried %file:~0,"."% but didn't work...

Answer 1

for /f "delims=." %%b in ("%file%") do set "prefix=%%b"

or, since this is a filename,

for %%b in ("%file%") do set "prefix=%%~nb"

Documentation : enter for /? at the prompt.