So, Mac OS X 10.11 came out a few days ago and I was keen to install and see what’s new. When it comes to OS upgrades, I prefer to perform a wipe and load of whatever system is, so that I start with a blank slate and build it back up. This helps eradicate those gnarly issues that can arise if an inplace upgrade is performed and old configurations can sometimes conflict with new binaries, libraries or simply just “new ways to do things”.

I started out on my Unix journey using Linux systems and once I started using Macs, it wasn’t long before I began to miss a fair few of the Linux commands and utilities that I had gotten used to using. The solution: Homebrew. It’s awesome! That’s all there is to it. If you’re not using it already, you should be - go get it!

The solution: Homebrew. It’s awesome! That’s all there is to it.

htop is an awesome process viewer for Unix based systems and it was the first thing I installed on my Mac, once I had Homebrew installed. One interesting point, though, is that htop on Mac OS needs to run as root in order to show all the running processes and their stats. Without root privileges, htop can only report on processes that the current user is running. On Linux, htop can be run by a non-privileged user and they can see (only) processes that are owned by other users on the system, including root’s processes.

I asked on SuperUser why this was the case. It turns out that on Linux, htop uses the /proc filesystem to gather process info, however on a Mac, there’s no /proc filesystem for htop to pull data from. Instead, it has to talk to the kernel and this is the step that requires root privileges. Thanks to Thomas Dickey on SuperUser for his answer explaining this.

This is a documented caveat with htop on OS X; it’s mentioned in the install information in the htop formula in the Homebrew repo that after install (see here), you need to run htop as root to see all the processes. For some time, the recommended workaround for this in the formula info was as follows:

sudo chown root:wheel $(which htop)
sudo chmod u+s $(which htop)

After that, htop can be run by simply typing:


However this was changed fairly recently to suggest that instead of the above, htop should be run with sudo instead:

sudo htop

I personally prefer the original workaround of setting the setuid bit on the htop binary, as this means I don’t have to setup a potentially messy Bash alias and I don’t have to remember to run with sudo on Mac and without sudo on Linux.

I’m sure there’ll be a reason (probably security related) why the move away from this method was taken by the Homebrew maintainers, but I thought it would be useful to explain this change and hopefully explain why root privileges are needed for htop to report on all processes on Mac OS X.

If you have any questions, or if you care to enlighten me on why it’s better to run htop as root through sudo on a Mac, rather than the setuid method above, then please feel free to comment below!