sb-nettraf: rewrite

common/.local/libexec/statusbar/sb-nettraf

@@ -1,20 +1,42 @@
 #!/bin/sh
 . libsb
-# TODO: Coloring based on speed
 
-update() {
-	sum=0
-	for arg; do
-		read -r i <"$arg"
-		sum=$((sum + i))
-	done
-	cache=$XDG_RUNTIME_DIR/${1##*/}
-	[ -f "$cache" ] && read -r old <"$cache" || old=0
-	printf "%b" "$sum\n" >"$cache"
-	printf "%b" "$((sum - old))\n"
+# NOTE: This should be executed once per second to get bps
+
+CACHE=$XDG_RUNTIME_DIR/nettrafcache
+
+get_physical_devices() {
+    nmcli -t -f STATE,DEVICE device | awk -F: '$1=="connected" { print $2 }'
 }
 
-rx=$(update /sys/class/net/[ew]*/statistics/rx_bytes)
-tx=$(update /sys/class/net/[ew]*/statistics/tx_bytes)
+get_bytes() {
+    cat "/sys/class/net/${1}/statistics/${2}_bytes" || echo 0
+}
 
-printf "%b%5sB %b%5sB%b" "" "$(numfmt --to=iec "$rx")" "" "$(numfmt --to=iec "$tx")" "\n"
+update() {
+    device=$1 cache=$2
+
+    rx_old=$(awk '$1=="rx" { print $2 }' "$cache" || echo 0)
+    tx_old=$(awk '$1=="tx" { print $2 }' "$cache" || echo 0)
+
+    rx_new=$(get_bytes "$device" rx)
+    tx_new=$(get_bytes "$device" tx)
+
+    printf "rx %s\n" "$rx_new" >"$cache"
+    printf "tx %s\n" "$tx_new" >>"$cache"
+
+    printf "rx=%s tx=%s" "$((rx_new - rx_old))" "$((tx_new - tx_old))"
+}
+
+rx_sum=0 tx_sum=0
+for device in $(get_physical_devices); do
+    cache=${CACHE}-${device}
+
+    rx=0 tx=0
+    eval "$(update "$device" "$cache")"
+
+    rx_sum=$((rx_sum + rx))
+    tx_sum=$((tx_sum + tx))
+done
+
+printf " %5sB  %5sB%b" "$(numfmt --to=iec "$rx_sum")" "$(numfmt --to=iec "$tx_sum")" "\n"