Add pending updates widget to xmobar

updates.sh shows the repo/AUR counts and pending kernel rebuilds from update-notify's pending file, and lists them in a notification on click.

.config/xmobar/updates.sh

@@ -0,0 +1,52 @@
+#!/bin/bash
+# Pending updates for xmobar from update-notify's pending list, e.g. " 15/3 | " (repo/AUR), empty when none
+# Entries already installed are dropped, so the count falls right after an upgrade. Orange from the threshold
+# on, red "K" when a custom kernel needs a rebuild.
+# With "list": show the pending packages in a notification (for a click on the bar)
+
+file="${XDG_STATE_HOME:-$HOME/.local/state}/update-notify/pending"
+[[ -r $file ]] || exit 0
+
+mapfile -t entries < "$file"
+names=()
+for e in "${entries[@]}"; do
+    read -r src pkg _ <<< "$e"
+    [[ $src != threshold ]] && names+=("$pkg")
+done
+
+declare -A installed
+if (( ${#names[@]} )); then
+    while read -r pkg ver; do
+        installed[$pkg]=$ver
+    done < <(pacman -Q "${names[@]}" 2>/dev/null)
+fi
+
+threshold=0 repo=() aur=() kernel=()
+for e in "${entries[@]}"; do
+    read -r src pkg new <<< "$e"
+    [[ $src == threshold ]] && { threshold=$pkg; continue; }
+    have=${installed[$pkg]:-}
+    [[ -z $have ]] && continue    # removed since the last run
+    case $src in
+        repo)   (( $(vercmp "$have" "$new") < 0 )) && repo+=("$pkg $new") ;;
+        aur)    (( $(vercmp "$have" "$new") < 0 )) && aur+=("$pkg $new") ;;
+        kernel) (( $(vercmp "${have%-*}" "${new%-*}") < 0 )) && kernel+=("$pkg (stock $new)") ;;
+    esac
+done
+
+if [[ ${1:-} == list ]]; then
+    body=""
+    (( ${#repo[@]} )) && { printf -v l '%s\n' "${repo[@]}"; body+="Repo:"$'\n'"$l"; }
+    (( ${#aur[@]} )) && { printf -v l '%s\n' "${aur[@]}"; body+="AUR:"$'\n'"$l"; }
+    (( ${#kernel[@]} )) && { printf -v l 'Rebuild %s\n' "${kernel[@]}"; body+="$l"; }
+    body=${body%$'\n'}
+    notify-send "Pending updates" "${body:-None}"
+    exit
+fi
+
+total=$(( ${#repo[@]} + ${#aur[@]} ))
+(( total + ${#kernel[@]} )) || exit 0
+text=$'\xef\x92\x87'" ${#repo[@]}/${#aur[@]}"    # nf-oct-package, as UTF-8 bytes so the locale doesn't matter
+(( total >= threshold )) && text="<fc=#ffb86c>$text</fc>"
+(( ${#kernel[@]} )) && text+=" <fc=#f7768e>K</fc>"
+echo "$text | "

.config/xmobar/xmobarrc_hdmi

@@ -51,9 +51,10 @@ Config { overrideRedirect   = True
                                 ] 600
                               , Run Com "/home/fuxino/.config/xmobar/pactl_volume.sh" [] "pactl_volume" 10
                               , Run Com "/home/fuxino/.config/xmobar/ens_brief.sh" [] "ens_brief" 18000
+                              , Run Com "/home/fuxino/.config/xmobar/updates.sh" [] "updates" 600
                               , Run UnsafeXMonadLog
                               ]
         , sepChar           = "%"
         , alignSep          = "}{"
-        , template          = "  | %UnsafeXMonadLog% } %uptime% | %multicpu% %coretemp% | %memory% |   %kbd% { <action=`/home/fuxino/.config/xmobar/ens_brief.sh week`>%LZIB% <fc=#565f89>·</fc> %ens_brief%</action> | %pactl_volume% | %date% "
+        , template          = "  | %UnsafeXMonadLog% } %uptime% | %multicpu% %coretemp% | %memory% |   %kbd% { <action=`/home/fuxino/.config/xmobar/updates.sh list`>%updates%</action><action=`/home/fuxino/.config/xmobar/ens_brief.sh week`>%LZIB% <fc=#565f89>·</fc> %ens_brief%</action> | %pactl_volume% | %date% "
         }

.config/xmobar/xmobarrc_laptop

@@ -52,9 +52,10 @@ Config { overrideRedirect   = True
                               , Run XPropertyLog "_XMONAD_TRAYPAD"
                               , Run Com "/home/fuxino/.config/xmobar/pactl_volume.sh" [] "pactl_volume" 10
                               , Run Com "/home/fuxino/.config/xmobar/ens_brief.sh" [] "ens_brief" 18000
+                              , Run Com "/home/fuxino/.config/xmobar/updates.sh" [] "updates" 600
                               , Run UnsafeXMonadLog
                               ]
         , sepChar           = "%"
         , alignSep          = "}{"
-        , template          = "  | %UnsafeXMonadLog% } %uptime% | %multicpu% %coretemp% | %memory% |   %kbd% { <action=`/home/fuxino/.config/xmobar/ens_brief.sh week`>%LZIB% <fc=#565f89>·</fc> %ens_brief%</action> | %pactl_volume% | %date% %_XMONAD_TRAYPAD% "
+        , template          = "  | %UnsafeXMonadLog% } %uptime% | %multicpu% %coretemp% | %memory% |   %kbd% { <action=`/home/fuxino/.config/xmobar/updates.sh list`>%updates%</action><action=`/home/fuxino/.config/xmobar/ens_brief.sh week`>%LZIB% <fc=#565f89>·</fc> %ens_brief%</action> | %pactl_volume% | %date% %_XMONAD_TRAYPAD% "
         }