Tag: Mac OS X (Page 1 of 4)

Clear Mac OS DNS cache via command line

October 28, 2025 / Chris Brewer / 0 Comments

The method for clearing or flushing the local cache in Mac OS has changed over the years. Here are all the Mac OS versions on one page that details how to clear Mac OS DNS cache via command line.

TLDR; Add this alias to your .zshrc file:

alias flushdns="sudo killall -HUP mDNSResponder;sudo killall mDNSResponderHelper;sudo dscacheutil -flushcache;say 'cache flushed' -v Tessa -r 229"

Then issue this command:

source ~/.zshrc

And now you can run this command and get nice audio confirmation:

flushdns

Clear your DNS cache on macOS Tahoe 26, macOS Sequoia 15, macOS Sonoma 14, macOS Ventura 13, macOS Monterey 12, macOS Big Sur 11, macOS 10.15 Catalina, macOS 10.14 Mojave, macOS 10.13 High Sierra, macOS 10.12 Sierra, OS X 10.11 El Capitan, OS X 10.10 Yosemite, OS X 10.9 Mavericks, OS X 10.8 Mountain Lion, OS X 10.7 Lion, OS X 10.6 Snow Leopard, and OS X 10.5 Leopard using the following Terminal commands:

Make your Mac chime at startup again

April 22, 2020 / Chris Brewer / 0 Comments

I miss the startup chime on my MacBook Pro. Make your Mac chime on startup again!

To enable it, open up terminal and type:

sudo nvram StartupMute=%00

To disable it, either reset your parameter RAM by pressing Command-Option-P-R at startup, or in terminal type:

sudo nvram StartupMute=%01

Colorize your Terminal shell on Mac OS

October 9, 2019 / Chris Brewer / 0 Comments

You need to add color into Mac OS terminal. Apple’s default settings for BASH are less than lovely — just shades of gray.

Terminal with Apple's default colors

Here’s how to add color to BASH for your visual enjoyment. Continue reading

Configure NPM for global user without sudo on Mac OS

October 9, 2019 / Chris Brewer / 0 Comments

Have you ever wanted to configure NPM for global user without sudo on Mac OS?

Using ‘sudo’ with NPM is a no-no, as it can cause all kinds of havoc with file permissions. But there is a way to avoid this heartache and misery!

You can specify a default directory for globally installed packages and thus absolve yourself of sudo chaos. Continue reading

Fix for Command & Conquer: Generals crashing in Mac

January 25, 2017 / Chris Brewer / 0 Comments

Command & Conquer: Generals crashing on Mac? As any Mac user knows, running Command and Conquer Generals (including Zero Hour) tends to crash on startup on a Mac running OS X. Here’s how to fix it. Continue reading

Remove TimeMachine Backups.backupdb file manually via terminal command line

December 23, 2014 / Chris Brewer / 0 Comments

I recently needed to delete the Backups.backupdb file via command line using the rm command. However, sudo user can’t do it, and neither can root. What’s a guy to do?

Clear the DNS cache on Mac OS

May 19, 2014 / Chris Brewer / 1 Comment

So you want to clear the DNS cache on Mac OS X Mavericks through the now-current Mac OS 26? Well, Mac OS since ‘Mavericks’ has some DNS changes under the hood. Unlike previous versions, to effectively clear the cache you need to execute these two commands in Terminal:

dscacheutil -flushcache;sudo killall -HUP mDNSResponder

Add this as an alias to your .profile under something easy to remember like ‘flushdns’ and you’re good to go!

Now you know how to clear the DNS cache on Mac OS.

Test whether outbound port is open on Mac OS X 10.9, 10.8, 10.7

December 2, 2013 / Chris Brewer / 0 Comments

Wondering if a certain outbound port on your Mac is open or closed? Here’s a way to determine outbound open ports on Mac OS using netcat via the command line in terminal. We’ll use using a free service from portquiz.net.

From the terminal, enter:

nc -v portquiz.net 443

where 443 is the port number you want to test.

Control-c will kill net cat after you get the info you want.

Easy-peasy. You can now determine outbound open ports on Mac OS.

Enable USB install option in Bootcamp 5

April 30, 2013 / Chris Brewer / 2 Comments

Apple prevents computers with USB drives from installing Windows from a USB flash drive on certain models. While it works flawlessly on my current gen MacBook Air, installing Windows 7 off a USB key doesn’t work on my iMac.

Luckily, the fix is easy…