If you’re troubleshooting a Mac machine with some particularly odd issues that routine measures don’t seem to be resolving, it can be helpful to list what kernel extensions are activated, particularly third party kexts loaded in OS X.
Determining what kernel extensions are loaded and running in Mac OS X is rather easy, and using grep you can then easily list all third party kexts. You can also use the same command to list native kernel extensions as well. To accomplish this, you’ll use the kextstat command and pipe the output to grep, using the command line. This works the same in all versions of Mac OS X.
How to See All Third Party Kernel Extensions in Mac OS X
The full syntax to see third party kernel extensions is as follows:
kextstat | grep -v com.apple
The output is going to vary depending on what, if any, third party extensions are in the kernel. It may look something like this:
Index Refs Address Size Wired Name (Version) Linked Against 117 0 0xffdddfff8209ff910 0x2000 0x2000 com.radiosilenceapp.nke.PrivateEye (1) 4 1 119 0 0xfffff945818248770 0x3000 0x3000 com.whattheheckisthis.WeirdExtension (1) 5 2
If you see something out of place in that list, that could be a good place to start troubleshooting.
How to List All Kernel Extensions in OS X
Of course you can always list all kernel extensions (meaning, Apple’s official Mac OS X kexts included) by just typing the following command string:
kextstat
The output here is going to be significant, but it can still be valuable.
If you want to learn more about kextstat, just type ‘man kextstat’ to open the man page in the OS X Terminal.
Don’t forget that you can manually inspect the traditional kernel extension system folder location as well if necessary, even moving and removing kext files from there to aid in the process of installing, uninstalling, troubleshooting, or discovery of kernel extensions.