IT notes


To remove a user from the login screen when booting and login from the first time: sudo fdesetup remove -user monkey The user will not be listed any more in the login screen, but you will need first logging with a user that can decrypt the disk and then switch to your user. Note this will not delete or remove the user account

Flush DNS

To flush DNS on macOS: sudo killall -HUP mDNSResponder;sudo killall mDNSResponderHelper;sudo dscacheutil -flushcache

Prevent Mac to Sleep

To stop sleep entirely: sudo pmset -a disablesleep 1 To revert, allow sleep again: sudo pmset -a disablesleep 0 To display global power settings: pmset -g


In macOS, to find a path of an application, for example Chromium: $ osascript -e 'POSIX path of (path to application "Chromium")'


softwareupdate -l to see if there are macOS updates available. softwareupdate -ia to install all updates. sudo jamf policy to run all outstanding policies and updates for the apps, sudo jamf recon to update the inventory on the server.


In macOS High Sierra if getting this: objc[55492]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. objc[55492]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug. Define: export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES This will fix temporally fix the problem and allow program to continue executing, more about this issue here: http://sealiesoftware.

Linux Mac Address

To get the MAC address from an interface in linux: cat /sys/class/net/eth1/address

dsymutil golang

Go executables broken in macOS 10.12.X When compiling and executing this may happen: $ zsh: killed ./main Temporary fix: $ ln -s /usr/bin/true /usr/local/bin/dsymutil

ipv6 off

Turn off IPv6 on mac First list interfaces: $ networksetup -listallnetworkservices An asterisk (*) denotes that a network service is disabled. Thunderbolt Ethernet Wi-Fi Bluetooth PAN Thunderbolt Bridge Next: $ networksetup -setv6off "Thunderbolt Ethernet" For Wi-Fi: $ networksetup -setv6off Wi-Fi

brew macos

Homebrew installs the stuff you need that Apple didn’t. For example to update python and avoid many SSL warnings: brew install python To use an updated version of git on mac use: brew install git --whitout-completion To update vim: brew install vim --with-override-system-vi Updating zsh: # check the zsh info brew info zsh # install zsh brew install zsh # add shell path sudo vim /etc/shells # add the following line into the very end of the file(/etc/shells) /usr/local/bin/zsh # change default shell chsh -s /usr/local/bin/zsh Install some extra packages in oneline: