Kindly move to the right thread, just in case I missed it. Hello, I'm looking for software that can detect used or unused programs on Linux.
apt list --installed dpkg -l you can list everything that's installed ( apart from manually compiled/installed software) as for whether it's used or not. nope. probably the nearest you'll get is to look at the last accessed or last modified date/time for the file. but even if it says accessed/modified this morning that guarantees nothing, could be something you don't use, that was installed by default, and was updated by apt. if you're trying to see what's actually running/in use right now. ps, top, htop.... for general server monitoring, monit, munin, nagios, icinga...
I'd like to know what you wish to do with such info because in my experience people asking this question wishes to minimize their hdd usages but what you installed is normally what you have. However, if you wish to detect "a virus" then anti-virus (or malware, ransomware etc) software is what you want running.
Better ask via opening a new post rather than editing your opening post. Anyway, your questions had already been answered above and there is no need to move this any where else.
