Fix optional shellcheck warnings

Additionally fix a few code style issues found with shfmt.

airootfs/root/.automated_script.sh

@@ -1,17 +1,18 @@
 #!/usr/bin/env bash
 
-script_cmdline ()
-{
+script_cmdline() {
     local param
-    for param in $(< /proc/cmdline); do
+    for param in $(</proc/cmdline); do
         case "${param}" in
-            script=*) echo "${param#*=}" ; return 0 ;;
+            script=*)
+                echo "${param#*=}"
+                return 0
+                ;;
         esac
     done
 }
 
-automated_script ()
-{
+automated_script() {
     local script rt
     script="$(script_cmdline)"
     if [[ -n "${script}" && ! -x /tmp/startup_script ]]; then

airootfs/usr/local/bin/choose-mirror

@@ -4,21 +4,22 @@
 
 get_cmdline() {
     local param
-    for param in $(< /proc/cmdline); do
+    for param in $(</proc/cmdline); do
         case "${param}" in
-            $1=*) echo "${param##*=}";
-            return 0
-            ;;
+            "${1}="*)
+                echo "${param##*=}"
+                return 0
+                ;;
         esac
     done
 }
 
-mirror=$(get_cmdline mirror)
-[[ $mirror = auto ]] && mirror=$(get_cmdline archiso_http_srv)
-[[ $mirror ]] || exit 0
+mirror="$(get_cmdline mirror)"
+[[ "$mirror" == 'auto' ]] && mirror="$(get_cmdline archiso_http_srv)"
+[[ -n "$mirror" ]] || exit 0
 
 mv /etc/pacman.d/mirrorlist /etc/pacman.d/mirrorlist.orig
-cat >/etc/pacman.d/mirrorlist << EOF
+cat >/etc/pacman.d/mirrorlist <<EOF
 #
 # Arch Linux repository mirrorlist
 # Generated by archiso

airootfs/usr/local/bin/livecd-sound

@@ -3,7 +3,7 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 usage() {
-    cat <<- _EOF_
+    cat <<-_EOF_
     live cd sound helper script.
     Usage: livecdsound [OPTION]
     OPTIONS
@@ -14,14 +14,13 @@ usage() {
 _EOF_
 }
 
-bugout () {
+bugout() {
     printf "/usr/local/bin/livecdsound: programming error"
     stat_fail
 }
 
-echo_card_indices()
-{
-    if [ -f /proc/asound/cards ] ; then
+echo_card_indices() {
+    if [[ -f /proc/asound/cards ]]; then
         sed -n -e's/^[[:space:]]*\([0-7]\)[[:space:]].*/\1/p' /proc/asound/cards
     fi
 }
@@ -33,8 +32,8 @@ echo_card_indices()
 # $1 <card id>
 # $2 <control>
 # $3 <level>
-unmute_and_set_level(){
-    { [ "$3" ] &&[ "$2" ] && [ "$1" ] ; } || bugout
+unmute_and_set_level() {
+    [[ -n "$3" && -n "$2" && -n "$1" ]] || bugout
     systemd-cat -t "livecdsound" printf "Setting: %s on card: %s to %s\n" "$2" "$1" "$3"
     systemd-cat -t "livecdsound" amixer -c "$1" set "$2" "$3" unmute
     return 0
@@ -42,9 +41,8 @@ unmute_and_set_level(){
 
 # $1 <card id>
 # $2 <control>
-mute_and_zero_level()
-{
-    { [ "$1" ] && [ "$2" ] ; } || bugout
+mute_and_zero_level() {
+    [[ -n "$1" && -n "$2" ]] || bugout
     systemd-cat -t "livecdsound" printf "Muting control: %s on card: %s\n" "$2" "$1"
     systemd-cat -t "livecdsound" amixer -c "$1" set "$2" "0%" mute
     return 0
@@ -53,17 +51,15 @@ mute_and_zero_level()
 # $1 <card ID>
 # $2 <control>
 # $3 "on" | "off"
-switch_control()
-{
-    { [ "$3" ] && [ "$1" ] ; } || bugout
+switch_control() {
+    [[ -n "$3" && -n "$1" ]] || bugout
     systemd-cat -t "livecdsound" printf "Switching control: %s on card: %s to %s\n" "$2" "$1" "$3"
     systemd-cat -t "livecdsound" amixer -c "$1" set "$2" "$3"
     return 0
 }
 
 # $1 <card ID>
-sanify_levels_on_card()
-{
+sanify_levels_on_card() {
     unmute_and_set_level "$1" "Front" "80%"
     unmute_and_set_level "$1" "Master" "80%"
     unmute_and_set_level "$1" "Master Mono" "80%"
@@ -134,94 +130,89 @@ sanify_levels_on_card()
 }
 
 # $1 <card ID> | "all"
-sanify_levels()
-{
+sanify_levels() {
     local ttsdml_returnstatus=0
     local card
     case "$1" in
-              all)
-        for card in $(echo_card_indices) ; do
-            sanify_levels_on_card "$card" || ttsdml_returnstatus=1
-        done
-        ;;
-      *)
-        sanify_levels_on_card "$1" || ttsdml_returnstatus=1
-        ;;
+        all)
+            for card in $(echo_card_indices); do
+                sanify_levels_on_card "$card" || ttsdml_returnstatus=1
+            done
+            ;;
+        *)
+            sanify_levels_on_card "$1" || ttsdml_returnstatus=1
+            ;;
     esac
-    return $ttsdml_returnstatus
+    return "$ttsdml_returnstatus"
 }
 
 # List all cards that *should* be usable for PCM audio.  In my experience,
 # the console speaker (handled by the pcsp driver) isn't a suitable playback
 # device, so we'll exclude it.
-list_non_pcsp_cards()
-{
+list_non_pcsp_cards() {
     for card in $(echo_card_indices); do
         local cardfile="/proc/asound/card${card}/id"
-        if [ -r "$cardfile" ] && [ -f "$cardfile" ] && \
-            [ "$(cat "$cardfile")" != pcsp ]; then
+        if [[ -r "$cardfile" && -f "$cardfile" && "$(cat "$cardfile")" != pcsp ]]; then
             echo "$card"
         fi
     done
 }
 
 # Properly initialize the sound card so that we have audio at boot.
-unmute_all_cards()
-{
+unmute_all_cards() {
     sanify_levels all
 }
 
 is_numeric() {
-    local str=$1
+    local str="$1"
     [[ "$str" =~ ^[0-9]+$ ]]
 }
 
 set_default_card() {
-    local card=$1
-    sed -e "s/%card%/$card/g" < /usr/local/share/livecd-sound/asound.conf.in \
-        > /etc/asound.conf
+    local card="$1"
+    sed -e "s/%card%/$card/g" </usr/local/share/livecd-sound/asound.conf.in \
+        >/etc/asound.conf
 }
 
 play_on_card() {
-    local card=$1 file=$2
+    local card="$1" file="$2"
     aplay -q "-Dplughw:$card,0" "$file"
 }
 
 # If there are multiple usable sound cards, prompt the user to choose one,
 # using auditory feedback.
-pick_a_card()
-{
+pick_a_card() {
     set -f
     usable_cards="$(list_non_pcsp_cards)"
-    num_usable_cards="$(wc -w <<< "$usable_cards")"
+    num_usable_cards="$(wc -w <<<"$usable_cards")"
 
-    if [ "$num_usable_cards" -eq 1 ]; then
+    if (( num_usable_cards == 1 )); then
         systemd-cat -t "livecdsound" printf "Only one sound card is detected\n"
         exit 0
     fi
     systemd-cat -t "livecdsound" printf "multiple sound cards detected\n"
-    for card in $usable_cards; do
+    for card in "${usable_cards[@]}"; do
         if ! is_numeric "$card"; then
             continue
         fi
-        play_on_card "$card" /usr/share/livecd-sounds/pick-a-card.wav&
+        play_on_card "$card" /usr/share/livecd-sounds/pick-a-card.wav &
     done
     wait
     sleep 1
-    for card in $usable_cards; do
+    for card in "${usable_cards[@]}"; do
         if ! is_numeric "$card"; then
             continue
-    fi
-    play_on_card "$card" /usr/share/livecd-sounds/beep.wav
-    if read -r -t 10; then
-        systemd-cat -t "livecdsound" printf "Selecting %s sound card as default\n" "$card"
-        set_default_card "$card"
-        break
-    fi
-done
+        fi
+        play_on_card "$card" /usr/share/livecd-sounds/beep.wav
+        if read -r -t 10; then
+            systemd-cat -t "livecdsound" printf "Selecting %s sound card as default\n" "$card"
+            set_default_card "$card"
+            break
+        fi
+    done
 }
 
-if [[  $# -eq 0 ]]; then
+if (( $# == 0 )); then
     echo "error: No argument passed."
     exit 1
 fi