PHP - Help removing file extension from this regex

Hi, I'm fairly new to regular expressions but I was able to put together most of what I need, just having a problem trying to figure out how to capture everything between the two round brackets minus the .txt extension. This is what I have so far:

#\/Type \/Filespec[\n]\/F \((.*?)\)#

I'm trying to use that regex on this data:

/Type /Filespec
/F (file_name.txt)

Trying to capture just, file_name, but it's giving me file_name.txt right now. I've tried this regex as well but no luck when using it with preg_match:

#\/Type \/Filespec[\n]\/F \((.*?)\).txt#

I would appreciate any help with this.

That would work for "/F (file_name).txt".

Move the ".txt" one spot earlier. And escape the period so it's not a metacharacter.

Thank you requinix, that worked perfectly.