The Living Thing / Notebooks :

Passive-aggressive advice on making OSX behave itself

Things I have to do so often to keep my laptop running that I'd prefer not to google them. Now with macOS support!

See also command lines it is tedious to remember for general unix/osx/BSD commands.

Most of these commands are supposed to be run sudo root, and each may irremediably fuck up your computer, your life, and everything you have ever loved. Then it might challenge you to a break dance battle, I dunno. It won't be my fault.

UPDATE: So many of these were filesystem-specific hacks that I broke out those into an article on filesystem-specific hacks. And others were about easing the pains of using osx in the low-bandwidth majority world or OSX server.

The remaining general ones are arranged so that the further you get down the list the longer it is since I have needed to know it; the later ones probably don't work on modern macOS.

The motherships

Config files

Mathias Bynens and his incredible atomic dotfiles.


macOS Security and Privacy Guide.

Renew DHCP lease

My shitty router gets cross if I leave the house and when I come back I try to use the same DHCP lease. But it's a one-liner to fix.

sudo ipconfig set en0 DHCP
ipconfig getpacket en0

Which process is bound to $PORT?

this one.

lsof -nP -i4TCP:$PORT | grep LISTEN # High Sierra or later
lsof -nP -iTCP:$PORT | grep LISTEN earlier

Which file is crashing/hanging that process?

Perpetual monitoring natively:

fs_usage PID | grep /path/to/file

or the classic unix way:

lsof -r -p PID | grep /path/to/file

See here for some tips on debugging runaway/hung/exploded processes in more ways. “See what syscalls does the process actually try to do and if there are any failed ones (status is not 0)” :

sudo dtruss -p PID

Case study: distnoted and lsd.

distnoted runaway CPU

This is some kind of notifications daemon. I have no idea why it is out of control. It seems to be related to other processes such as certain version of flux or bartender. but the problem only seems to occur when my backup drive is plugged in. Hmmph. File a ticket?

Michael Rourke suggests doing this every minute:

# check for runaway distnoted, kill if necessary
export PATH

ps -reo '%cpu,uid,pid,command' |
    awk -v UID=$UID '
    /distnoted agent$/ && $1 > 100.0 && $2 == UID {
        system("kill -9 " $3)

But note that this will break backup.

lsd runaway CPU

Some indexing jobs can cause it to choke, e.g. application bundles. Also, a corrupted database, which may be fixed thusly:

/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister \
    -kill -r -domain local -domain system -domain user ; killall Dock

Stop stealing focus from me, slow app, I clicked on you like 30 seconds ago

CNET says: How to keep applications from stealing focus. But their first idea (edit application, break code signature) is not a viable idea in the modern world.

The command-line background-open still works:

open -ga iCal

OSX claims it forgot my email/contacts/calendar password again

Then an hour later it forgets again again?

Woe! I fixed this once then I forgot how I did it.

Linkdump while I sort it out again again again:

Continuous [sic] request for the CalDav password

Here's one solution:

  1. Go to the  Apple menu and choose System Preferences
  2. Choose the ‘iCloud’ preference pane
  3. Sign in to iCloud at the OS X preference panel – note if you’re already signed in here but still seeing the pop-up message, you can sign out then sign back in to stop that password prompt from happening again
  4. Close System Preferences

plist files are opaque binary messes

This is how to convert them to text. If you regard XML as text.

Now my machine won't boot properly heeeeeelp

I wouldn't panic yet, probably the bootloadey whodangle thingy is broken again.

(Also applies if your CPU fan is going all the time, your machine is pausing lots, you are having trouble getting laid, or a global geopolitical malaise is leading to the ineluctable slide of civilisation into ecosocial catastrophe.)

Do these things:

Other boot key combos of note

offer a boot menu
boot up off CD/USB
Recovery OS
Safe mode
verbose mode
single user prompt

DNS is all fucked up

DNS flush command keeps changing, eh?:

sudo dscacheutil -flushcache
sudo killall -HUP mDNSResponder

FFS iTunes never finishes syncing my phone it just stays stuck on “importing photos”

Because you don't use iCloud, right? For one thing, why would you voluntarily put your private photos in the hands of some notoriously secretive third party? For another, even if you wanted to, if you live in a bandwidth-poor country, iCloud sync is not just bad, it's comedically bad. Atrociously, OS-floggingly slow and glitchy. “iClod”, let us call it. So you sync using a cable and iTunes, of course.

Except that, every couple of days, that breaks. Heres how to fix it. (Note that this question refers to “iPhoto”, but the same bug has been faithfully carried over and reproduced in Aperture and Photos by diligent Apple devs, and the same fix works.)

Quit iTunes

$ rm -rf ~/Pictures/iPod\ Photo\ Cache
$ rm -rf ~/Pictures/Photos\ Library.photoslibrary/iPod\ Photo\ Cache

Note that this will reset iTunes to not sync your images, so you might need to reconstruct your settings.

Do that, try again.

Creating GUIs for shell scripts

Various options.

Automatically anonymized system stats


Change default shell

If you are reading this you are enough of a geek to need xcode

Run this:

xcode-select --install

Using Chromium ("open-source chrome")

Harder than it should be; Google really wants you to use their furtively modified alternate branch, Google Chrome.

Anyway, here is a supplier of unsullied Chromium. is illegible, blurry, slow

Yeah, some versions are broken. The official solution is to Turn it off and on again.

rm -r Containers/ \
    Containers/ \
    Preferences/ \
    Preferences/ \
    'Saved Application State/'

I found the problem could be avoided by using

Reset semaphores

I can't even remember why I needed to do this, or how I worked it out, but geez it saved my bacon from something or other.

ipcs -s | grep " 0x" | awk '{ print $2; }' | xargs -n 1 ipcrm -s

My arbitrary server process is running out of file handles

Hmm, who knows how this works on the latest versions?

But the traditional advice is:

ulimit -S -n 2048

How do I stop my disk filling up with temporary backups?


sudo tmutil disablelocal

This shouldn't be necessary, but I noticed that my spotlight indexing was stuck on the mobilebackups folder for some reason. Why was it even?

Re-time stupid alarms

By default, if you use notifications from Apple Calendar, the notification for events is at 9am, right in the middle of the first meeting of the day. So you are half way through the report-back presentation about your recent conference visit, your laptop pops up RECTAL EXAMINATION TODAY.

You aren't supposed to be able to change this because the thought of this cruelty is all that gets jaded Apple executives out of bed in the morning, but there is a hack they forgot to stop.

Stop gamed and other processes leaking your data and wasting precious network sockets for no reason

binary bob says :

sudo defaults write /System/Library/LaunchAgents/ disabled -bool true


launchctl unload -w /System/Library/LaunchAgents/

in reference to this.

Saving 300MB from skype on general principle

Update: the new version of Skype actually keeps this offal in the cache folder. (I imagine this is purely because of my passive-aggressive complaining. You're welcome.) So now you don't need to delete it. Unless you are deleting skype, which I did.

Since Skype is spookware I keep on my hard disk out of necessity, I am always mildly offended that it takes up 300MB of hard disk space for cached emoji for every single skype username. (update: last time I checked they had managed to get it down to 200mb; still too much.)

This is all to store videos of Fozzie Bear and Christmas ornaments. The biggest Emoji-jockey on earth will never use 90% of this shit, and even though it claims to be a “cache”, it's not in a cache folder, so it clogs up your backups with Fozzie Bear pictures. Put this in a launch agent:

rm -rf ~/Library/Application\ Support/Skype/*/media_messaging/*_cache_*

Don't worry, Skype still works, and recreates the folder for you with the obsessiveness of a meth addict trying to polish your windshield; really you just need to remember that some Skype calls might be free in dollars, but they bill you 300mb of disk space/bandwidth for every call as well as the recordings of your cybersex, but you can get the 300MB disk space back afterwards, whereas the dick pics are lost to the US government forever. (It doesn't seem to work if you trigger it from a folder action, so I set up a cron job to run that command every 10 minutes.)

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