Mac Notes

This blog illustrates some notes on using my Mac (model was released in mid 2015, OS is Catalina 10.15).

Clean Unused Homebrew Dependencies

Like apt-get autoremove in Ubuntu, I have too many unused homebrew dependencies and want to clean them.

brew bundle dump && brew bundle --force cleanup

Accented Chars vs. Key Repeat

Mac enables users to hold down a letter key and show accented or special chars.

To enable pop-up and disable key repeat, could set ApplePressAndHoldEnabled to true:

defaults write -g ApplePressAndHoldEnabled -bool true

However, as I used Vim(commands and config) more and more, I see popping up the accented chars less useful.

To disable pop-up and enable key repeat, could set ApplePressAndHoldEnabled to false:

defaults write -g ApplePressAndHoldEnabled -bool false

German Key Combs

Happy ending? Not yet! I recently started learning German and had to find some workaround to type the following chars and symbols (using US keyboard layout).

The German letters:

• ä: Option u + a
• ö: Option u + o
• ü: Option u + u
• ß: Option s

The lower and upper quotes:

• „: Option Shift w
• ”: Option Shift [

The Euro symbol:

• €: Option Shift 2

Note that I actually searched online and saw other key combs, but don't work.

Add Input Source

Another way to guarantee typing the correct German chars, or any language's chars is to use the corresponding input source. This could be done on Mac by: System Preferences $\rightarrow$ Keyboard $\rightarrow$ Input Souces $\rightarrow$ $+$ $\rightarrow$ {another language}.

Further

Please see this article for more details (opens new window) on keyboard viewer, quotes, ellipsis, and IA writer.

Terminal Caveats

Following are some common caveats for Unix terminal.

Change Root Password

sudo passwd root

Terminal Proxy w/ Socks5

It's fairly easy to use a socks5 proxy in browser, but how to use it in terminal, especially when downloading from GitHub is super slow in China? From this article (opens new window) I made the following terminal proxy settings.

In sock5 proxy app set:

• Local Socks5 Listen Address $\rightarrow$ 127.0.0.1
• Local Socks5 Port $\rightarrow$ 1086
• Connection Timeout $\rightarrow$ 60

Then in sh config file (.bashrc for Bash):

# set/unset proxy in terminal
alias setproxy="export ALL_PROXY=socks5://127.0.0.1:1086"
alias unsetproxy="set -e ALL_PROXY"

# set/unset proxy just for Git
alias agent="git config --global http.proxy socks5://127.0.0.1:1086;git config --global https.proxy socks5://127.0.0.1:1086;git config --global http.sslVerify false"
alias unagent="git config --global --unset http.proxy;git config --global --unset https.proxy"

Disable Proxy for Development Server

SET NO_PROXY=localhost
yarn start # or `npm run start`

Mute/Unmute Startup Chime

# mute
sudo nvram StartupMute=%01
# unmute
sudo nvram StartupMute=%00

Fish Set Path

# set path
set PATH <newdir> $PATH

nohup not Hang Up

From here (opens new window) I see:

shopt | grep hupon

Check Disk Space

How to check free disk space in Linux (opens new window)

Search for some Pattern in a Directory

Search for some Pattern in a Directory (opens new window)

Why a Process is Killed

dmesg -T | egrep -i 'killed process'

Delete a Folder Quickly

perl -e 'for(<*>){((stat)[9]<(unlink))}'

Folder Sizes under Current Directory in Descending Order

du -sch * .[!.]* | sort -rh

Change Priority of Scheduled Job

Whenever any process is started in Linux, it is assigned a priority level of 0 by default. Linux Kernel automatically schedules the process and allocates CPU time accordingly for each process.

However, if we want to define the priority level of a process while launching it, we can do so using the nice command utility. If we want to define the priority level of a running process, we can use the renice command utility.

The priority level of a process is called as nice value of the process. In Linux, this nice value can range from $-20$ to $19$.

TODO: merge this file w/ shell.md