diff --git a/bin/create_boot_disk b/bin/create_boot_disk
index b47bddc..5e2b486 100755
--- a/bin/create_boot_disk
+++ b/bin/create_boot_disk
@@ -2,33 +2,33 @@
 
 # Creates macOS boot disk.
 
-printf "macOS Boot Disk Tips\n"
-printf "  - Use a USB drive (8GB or higher).\n"
-printf "  - Use Disk Utility to format the USB drive as \"APSF\".\n"
-printf "  - Use Disk Utility to label the USB drive as \"Untitled\".\n"
-printf "\nmacOS Boot Disk Usage:\n"
-printf "  1. Insert the USB boot disk into the machine to be upgraded.\n"
-printf "  2. Reboot the machine.\n"
-printf "  3. Press and hold the POWER key before the Apple logo appears.\n"
-printf "  4. Select the USB boot disk from the menu.\n"
-printf "  5. Use Disk Utility to delete and/or erase the hard drive including associated partitions.\n"
-printf "  6. Use Disk Utility to create a single \"APFS\" drive.\n"
-printf "  7. Install the new operating system.\n"
-printf "\nmacOS Boot Disk Recovery:\n"
-printf "  1. Start/restart the machine.\n"
-printf "  2. Press and hold the POWER key before the Apple logo appears.\n"
-printf "  3. Wait for the macOS installer to load from the recovery partition.\n"
-printf "  4. Use the dialog options to launch Disk Utility, reinstall the system, etc.\n"
+printf "%s\n" "macOS Boot Disk Tips"
+printf "%s\n" "  - Use a USB drive (8GB or higher)."
+printf "%s\n" "  - Use Disk Utility to format the USB drive as \"APSF\"."
+printf "%s\n" "  - Use Disk Utility to label the USB drive as \"Untitled\"."
+printf "\n%s\n" "macOS Boot Disk Usage:"
+printf "%s\n" "  1. Insert the USB boot disk into the machine to be upgraded."
+printf "%s\n" "  2. Reboot the machine."
+printf "%s\n" "  3. Press and hold the POWER key before the Apple logssssso appears."
+printf "%s\n" "  4. Select the USB boot disk from the menu."
+printf "%s\n" "  5. Use Disk Utility to delete and/or erase the hard drive including associated partitions."
+printf "%s\n" "  6. Use Disk Utility to create a single \"APFS\" drive."
+printf "%s\n" "  7. Install the new operating system."
+printf "\n%s\n" "macOS Boot Disk Recovery:"
+printf "%s\n" "  1. Start/restart the machine."
+printf "%s\n" "  2. Press and hold the POWER key before the Apple logo appears."
+printf "%s\n" "  3. Wait for the macOS installer to load from the recovery partition."
+printf "%s\n" "  4. Use the dialog options to launch Disk Utility, reinstall the system, etc."
 
-printf "\nCreating macOS boot disk...\n"
+printf "\n%s\n" "Creating macOS boot disk..."
 
 if [[ ! -e "$MAC_OS_BOOT_DISK_CREATOR" ]]; then
-  printf "ERROR: macOS installer does not exist: $MAC_OS_BOOT_DISK_CREATOR. Use System Preferences → Software Update to download.\n"
+  printf "%s\n" "ERROR: macOS installer does not exist: $MAC_OS_BOOT_DISK_CREATOR. Use System Preferences → Software Update to download."
   exit 1
 fi
 
 if [[ ! -d "$MAC_OS_BOOT_DISK_PATH" ]]; then
-  printf "ERROR: Boot disk must be mounted at: $MAC_OS_BOOT_DISK_PATH.\n"
+  printf "%s\n" "ERROR: Boot disk must be mounted at: $MAC_OS_BOOT_DISK_PATH."
   exit 1
 fi
 
diff --git a/bin/install_app_store b/bin/install_app_store
index e562d58..2fe1453 100755
--- a/bin/install_app_store
+++ b/bin/install_app_store
@@ -13,5 +13,5 @@ if [[ -x "$SCRIPT_PATH" ]]; then
   check_mas_install
   "$SCRIPT_PATH"
 else
-  printf "WARNING: App Store install script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: App Store install script does not exist or is not executable."
 fi
diff --git a/bin/install_applications b/bin/install_applications
index 477a4f0..c0276c3 100755
--- a/bin/install_applications
+++ b/bin/install_applications
@@ -12,5 +12,5 @@ SCRIPT_PATH="$MAC_OS_CONFIG_PATH/bin/install_applications"
 if [[ -x "$SCRIPT_PATH" ]]; then
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Applications install script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Applications install script does not exist or is not executable."
 fi
diff --git a/bin/install_basics b/bin/install_basics
index f121741..52bad38 100755
--- a/bin/install_basics
+++ b/bin/install_basics
@@ -12,5 +12,5 @@ SCRIPT_PATH="$MAC_OS_CONFIG_PATH/bin/install_basics"
 if [[ -x "$SCRIPT_PATH" ]]; then
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Basic settings script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Basic settings script does not exist or is not executable."
 fi
diff --git a/bin/install_defaults b/bin/install_defaults
index 9e27f97..1494f8f 100755
--- a/bin/install_defaults
+++ b/bin/install_defaults
@@ -12,5 +12,5 @@ SCRIPT_PATH="$MAC_OS_CONFIG_PATH/bin/install_defaults"
 if [[ -x "$SCRIPT_PATH" ]]; then
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Default settings script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Default settings script does not exist or is not executable."
 fi
diff --git a/bin/install_dev_tools b/bin/install_dev_tools
index 5b0c8fe..f26ebfb 100755
--- a/bin/install_dev_tools
+++ b/bin/install_dev_tools
@@ -1,14 +1,14 @@
 #! /usr/bin/env bash
 
-Installs development tooling requirements.
+# Installs development tooling requirements.
 
-printf "Installing Xcode CLI tools...\n"
+printf "%s\n" "Installing Xcode CLI tools..."
 xcode-select --install
 
 printf "%s\n" "💡 ALT+TAB to view and accept Xcode license window."
 read -p "Have you completed the Xcode CLI tools install (y/n)? " xcode_response
 if [[ "$xcode_response" != "y" ]]; then
-  printf "ERROR: Xcode CLI tools must be installed before proceeding.\n"
+  printf "%s\n" "ERROR: Xcode CLI tools must be installed before proceeding."
   exit 1
 fi
 
diff --git a/bin/install_extensions b/bin/install_extensions
index adc16de..4238a59 100755
--- a/bin/install_extensions
+++ b/bin/install_extensions
@@ -12,5 +12,5 @@ SCRIPT_PATH="$MAC_OS_CONFIG_PATH/bin/install_extensions"
 if [[ -x "$SCRIPT_PATH" ]]; then
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Application extensions install script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Application extensions install script does not exist or is not executable."
 fi
diff --git a/bin/install_homebrew_casks b/bin/install_homebrew_casks
index b647c49..34cc418 100755
--- a/bin/install_homebrew_casks
+++ b/bin/install_homebrew_casks
@@ -13,5 +13,5 @@ if [[ -x "$SCRIPT_PATH" ]]; then
   install_homebrew
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Homebrew Casks install script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Homebrew Casks install script does not exist or is not executable."
 fi
diff --git a/bin/install_homebrew_formulas b/bin/install_homebrew_formulas
index c8b8563..13f8fc9 100755
--- a/bin/install_homebrew_formulas
+++ b/bin/install_homebrew_formulas
@@ -13,5 +13,5 @@ if [[ -x "$SCRIPT_PATH" ]]; then
   install_homebrew
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Homebrew Formulas install script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Homebrew Formulas install script does not exist or is not executable."
 fi
diff --git a/bin/install_node_packages b/bin/install_node_packages
index 66ee4c7..e1c26fd 100755
--- a/bin/install_node_packages
+++ b/bin/install_node_packages
@@ -13,5 +13,5 @@ if [[ -x "$SCRIPT_PATH" ]]; then
   install_node
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Node packages install script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Node packages install script does not exist or is not executable."
 fi
diff --git a/bin/install_ruby_gems b/bin/install_ruby_gems
index d31451b..70a01a8 100755
--- a/bin/install_ruby_gems
+++ b/bin/install_ruby_gems
@@ -13,5 +13,5 @@ if [[ -x "$SCRIPT_PATH" ]]; then
   install_ruby
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Ruby gems install script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Ruby gems install script does not exist or is not executable."
 fi
diff --git a/bin/install_rust_crates b/bin/install_rust_crates
index 6600cdd..b153bc0 100755
--- a/bin/install_rust_crates
+++ b/bin/install_rust_crates
@@ -13,5 +13,5 @@ if [[ -x "$SCRIPT_PATH" ]]; then
   install_rust
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Rust crates install script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Rust crates install script does not exist or is not executable."
 fi
diff --git a/bin/install_shell b/bin/install_shell
index df7b206..f653fec 100755
--- a/bin/install_shell
+++ b/bin/install_shell
@@ -12,5 +12,5 @@ SCRIPT_PATH="$MAC_OS_CONFIG_PATH/bin/install_shell"
 if [[ -x "$SCRIPT_PATH" ]]; then
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Shell script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Shell script does not exist or is not executable."
 fi
diff --git a/bin/restore_backup b/bin/restore_backup
index 9bb01fe..aca97e3 100755
--- a/bin/restore_backup
+++ b/bin/restore_backup
@@ -12,5 +12,5 @@ SCRIPT_PATH="$MAC_OS_CONFIG_PATH/bin/restore_backup"
 if [[ -x "$SCRIPT_PATH" ]]; then
   "$SCRIPT_PATH"
 else
-  printf "WARNING: Restore backup script does not exist or is not executable.\n"
+  printf "%s\n" "WARNING: Restore backup script does not exist or is not executable."
 fi
diff --git a/bin/run b/bin/run
index 0b070b4..fe2c71a 100755
--- a/bin/run
+++ b/bin/run
@@ -11,13 +11,13 @@ source lib/verifiers.sh
 if [[ -e "$MAC_OS_CONFIG_PATH" ]]; then
   source "$MAC_OS_CONFIG_PATH/lib/settings.sh"
 else
-  printf "ERROR: Unable to load macOS configuration: $MAC_OS_CONFIG_PATH.\n\n"
-  printf "Please check the following before continuing:\n"
-  printf "  • Download the default macOS configuration here: https://github.com/bkuhlmann/mac_os-config.\n"
-  printf "  • Customize as necessary for your setup or fork the project and make your own configuration.\n"
-  printf "  • When finished, your folder structure should look like this:\n"
-  printf "    • <root path>/mac_os:\n"
-  printf "    • <root path>/mac_os-config:\n"
+  printf "%s\n\n" "ERROR: Unable to load macOS configuration: $MAC_OS_CONFIG_PATH."
+  printf "%s\n" "Please check the following before continuing:"
+  printf "%s\n" "  • Download the default macOS configuration here: https://github.com/bkuhlmann/mac_os-config."
+  printf "%s\n" "  • Customize as necessary for your setup or fork the project and make your own configuration."
+  printf "%s\n" "  • When finished, your folder structure should look like this:"
+  printf "%s\n" "    • <root path>/mac_os:"
+  printf "%s\n" "    • <root path>/mac_os-config:"
   exit 1
 fi
 
@@ -25,37 +25,37 @@ configure_environment
 
 while true; do
   if [[ $# == 0 ]]; then
-    printf "\nUsage: run OPTION\n"
-    printf "\nOSX Options:\n"
-    printf "  Boot:\n"
-    printf "     B:  Create boot disk.\n"
-    printf "  Install:\n"
-    printf "     b:  Install basics.\n"
-    printf "     t:  Install development tools.\n"
-    printf "    hf:  Install Homebrew Formulas.\n"
-    printf "    hc:  Install Homebrew Casks.\n"
-    printf "     m:  Install Mac App Store software.\n"
-    printf "     a:  Install application software.\n"
-    printf "     x:  Install application software extensions.\n"
-    printf "     d:  Install defaults.\n"
-    printf "     s:  Install shell.\n"
-    printf "     r:  Restore backups.\n"
-    printf "     i:  Install all (i.e. executes all of the above steps in order listed).\n"
-    printf "  Libraries:\n"
-    printf "    np:  Install Node packages.\n"
-    printf "    rg:  Install Ruby gems.\n"
-    printf "    rc:  Install Rust crates.\n"
-    printf "     l:  Install libraries (i.e. executes all of the above steps in order listed).\n"
-    printf "  Manage:\n"
-    printf "     c:  Check status of managed software.\n"
-    printf "     C:  Caffeinate machine.\n"
-    printf "     w:  Clean work (temp) directory.\n"
-    printf "     q:  Quit/Exit.\n\n"
+    printf "\n%s\n" "Usage: run OPTION"
+    printf "\n%s\n" "OSX Options:"
+    printf "%s\n" "  Boot:"
+    printf "%s\n" "     B:  Create boot disk."
+    printf "%s\n" "  Install:"
+    printf "%s\n" "     b:  Install basics."
+    printf "%s\n" "     t:  Install development tools."
+    printf "%s\n" "    hf:  Install Homebrew Formulas."
+    printf "%s\n" "    hc:  Install Homebrew Casks."
+    printf "%s\n" "     m:  Install Mac App Store software."
+    printf "%s\n" "     a:  Install application software."
+    printf "%s\n" "     x:  Install application software extensions."
+    printf "%s\n" "     d:  Install defaults."
+    printf "%s\n" "     s:  Install shell."
+    printf "%s\n" "     r:  Restore backups."
+    printf "%s\n" "     i:  Install all (i.e. executes all of the above steps in order listed)."
+    printf "%s\n" "  Libraries:"
+    printf "%s\n" "    np:  Install Node packages."
+    printf "%s\n" "    rg:  Install Ruby gems."
+    printf "%s\n" "    rc:  Install Rust crates."
+    printf "%s\n" "     l:  Install libraries (i.e. executes all of the above steps in order listed)."
+    printf "%s\n" "  Manage:"
+    printf "%s\n" "     c:  Check status of managed software."
+    printf "%s\n" "     C:  Caffeinate machine."
+    printf "%s\n" "     w:  Clean work (temp) directory."
+    printf "%s\n\n" "     q:  Quit/Exit."
     read -p "Enter selection: " response
     printf "\n"
-    process_option $response
+    process_option "$response"
   else
-    process_option $1
+    process_option "$1"
   fi
 
   break