polybar: Ignore/abort on missing commands/files

Catch if the files needed in the battery module are missing and exit
early.

Do not mess up the bar by printing error messages. Instead abort.

.config/polybar/scripts/battery.sh

@@ -11,8 +11,8 @@ red='%{F#f00}'
 green='%{F#0f0}'
 end='%{F-}'
 
-bat="$(cat /sys/class/power_supply/BAT0/capacity)"
-ac="$(cat /sys/class/power_supply/AC/online)"
+bat="$(cat /sys/class/power_supply/BAT0/capacity 2>/dev/null)" || exit
+ac="$(cat /sys/class/power_supply/AC/online 2>/dev/null)"
 declare -a ramp
 ramp=(          )
 

.config/polybar/scripts/media.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-command -v playerctl >/dev/null 2>&1 || { printf "playerctl not found.\n" >&2; exit 1; }
+command -v playerctl >/dev/null 2>&1 || exit 1
 
 metadata="$(playerctl metadata --format '{{status}} {{artist}}' 2>/dev/null)"
 title="$(playerctl metadata --format '{{title}}' 2>/dev/null)"