diff --git a/how-to-configure-self-hosted-vpn-kill-switch-using-pf-firewall-on-macos/README.md b/how-to-configure-self-hosted-vpn-kill-switch-using-pf-firewall-on-macos/README.md
index 497f1c5..c387043 100644
--- a/how-to-configure-self-hosted-vpn-kill-switch-using-pf-firewall-on-macos/README.md
+++ b/how-to-configure-self-hosted-vpn-kill-switch-using-pf-firewall-on-macos/README.md
@@ -289,12 +289,12 @@ cat << "EOF" > /usr/local/sbin/strict.sh
 #! /bin/sh
 
 if [ "$(id -u)" != "0" ]; then
-  echo "This script must run as root"
+  printf "%s\n" "This script must run as root"
   exit 1
 fi
 
 green=$'\e[1;32m'
-end=$'\e[0m'
+nc=$'\e[0m'
 
 # /usr/libexec/ApplicationFirewall/socketfilterfw --blockapp /Applications/1Password\ 7.app
 # /usr/libexec/ApplicationFirewall/socketfilterfw --blockapp /usr/local/Cellar/squid/4.8/sbin/squid
@@ -308,7 +308,7 @@ printf "\n"
 
 pfctl -F all -f /etc/pf.conf
 
-printf "\n%s" "${green}Strict mode enabled${end}"
+printf "\n${green}%s${nc}\n" "Strict mode enabled"
 EOF
 chmod +x /usr/local/sbin/strict.sh
 ```
@@ -322,7 +322,7 @@ cat << "EOF" > /usr/local/sbin/trusted.sh
 #! /bin/sh
 
 if [ "$(id -u)" != "0" ]; then
-  echo "This script must run as root"
+  printf "%s\n" "This script must run as root"
   exit 1
 fi
 
@@ -332,10 +332,10 @@ function disable()
   exit 0
 }
 
-trap disable HUP INT QUIT TERM
+trap disable INT
 
 red=$'\e[1;31m'
-end=$'\e[0m'
+nc=$'\e[0m'
 
 # /usr/libexec/ApplicationFirewall/socketfilterfw --unblockapp /Applications/1Password\ 7.app
 # /usr/libexec/ApplicationFirewall/socketfilterfw --unblockapp /usr/local/Cellar/squid/4.8/sbin/squid
@@ -349,7 +349,7 @@ printf "\n"
 
 pfctl -F all -f /etc/pf.conf
 
-printf "\n%s\n\n" "${red}Trusted mode enabled (press ctrl+c to disable)${end}"
+printf "\n${red}%s${nc}\n\n" "Trusted mode enabled (press ctrl+c to disable)"
 
 while :
 do
@@ -366,7 +366,7 @@ cat << "EOF" > /usr/local/sbin/disabled.sh
 #! /bin/sh
 
 if [ "$(id -u)" != "0" ]; then
-  echo "This script must run as root"
+  printf "%s\n" "This script must run as root"
   exit 1
 fi
 
@@ -376,14 +376,14 @@ function disable()
   exit 0
 }
 
-trap disable HUP INT QUIT TERM
+trap disable INT
 
 red=$'\e[1;31m'
-end=$'\e[0m'
+nc=$'\e[0m'
 
 pfctl -d
 
-printf "\n%s\n\n" "${red}Firewall disabled (press ctrl+c to enable)${end}"
+printf "\n${red}%s${nc}\n\n" "Firewall disabled (press ctrl+c to enable)"
 
 while :
 do
diff --git a/how-to-encrypt-sign-and-decrypt-messages-using-pgp-on-macos-adding-privacy-to-email/README.md b/how-to-encrypt-sign-and-decrypt-messages-using-pgp-on-macos-adding-privacy-to-email/README.md
index 0d5fc38..5424542 100644
--- a/how-to-encrypt-sign-and-decrypt-messages-using-pgp-on-macos-adding-privacy-to-email/README.md
+++ b/how-to-encrypt-sign-and-decrypt-messages-using-pgp-on-macos-adding-privacy-to-email/README.md
@@ -21,7 +21,7 @@ Publication date: 2020-06-18T00:00:00.000Z
 /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
 ```
 
-### Step 2: disable analytics
+### Step 2: disable Homebrew analytics
 
 ```shell
 brew analytics off
diff --git a/how-to-spoof-anonymize-your-mac-address-and-hostname-automatically-at-boot-on-macos/README.md b/how-to-spoof-anonymize-your-mac-address-and-hostname-automatically-at-boot-on-macos/README.md
index 472105a..7f227fe 100644
--- a/how-to-spoof-anonymize-your-mac-address-and-hostname-automatically-at-boot-on-macos/README.md
+++ b/how-to-spoof-anonymize-your-mac-address-and-hostname-automatically-at-boot-on-macos/README.md
@@ -40,21 +40,21 @@ export LC_CTYPE=C
 dirname=`dirname "${BASH_SOURCE}"`
 
 # Spoof computer name
-model_name=`system_profiler SPHardwareDataType | awk '/Model Name/ {$1=$2=""; print $0}' | sed -e 's/^[ ]*//'`
 first_name=`sed "$(jot -r 1 1 2048)q;d" $dirname/first_names.txt | sed -e 's/[^a-zA-Z]//g'`
-computer_name=`echo "$first_name’s $model_name"`
+model_name=`system_profiler SPHardwareDataType | awk '/Model Name/ {$1=$2=""; print $0}' | sed -e 's/^[ ]*//'`
+computer_name="$first_name’s $model_name"
 host_name=`echo $computer_name | sed -e 's/’//g' | sed -e 's/ /-/g'`
 sudo scutil --set ComputerName "$computer_name"
 sudo scutil --set LocalHostName "$host_name"
 sudo scutil --set HostName "$host_name"
-echo "Spoofed hostname to $host_name"
+printf "%s\n" "Spoofed hostname to $host_name"
 
 # Spoof MAC address of en0 interface
 mac_address_prefix=`sed "$(jot -r 1 1 768)q;d" $dirname/mac_address_prefixes.txt | sed -e 's/[^A-F0-9:]//g'`
 mac_address_suffix=`openssl rand -hex 3 | sed 's/\(..\)/\1:/g; s/.$//'`
 mac_address=`echo "$mac_address_prefix:$mac_address_suffix" | awk '{print toupper($0)}'`
 sudo ifconfig en0 ether "$mac_address"
-echo "Spoofed MAC address of en0 interface to $mac_address"
+printf "%s\n" "Spoofed MAC address of en0 interface to $mac_address"
 EOF
 ```