Merge pull request #187 from IGLOU-EU/patch-2

Update network-bandwidth configuration and documentation

INSTALL.md

@@ -152,6 +152,18 @@ Customize label
 set -g @dracula-ram-usage-label "RAM"
 ```
 
+#### network-bandwidth
+
+You can configure which network interface you want to view the bandwidth,
+Displaying of the interface name, The interval between each bandwidth update.
+The most common interfaces name are `eth0` for a wired connection and `wlan0` for a wireless connection.
+
+```bash
+set -g @dracula-network-bandwidth eth0
+set -g @dracula-network-bandwidth-interval 0
+set -g @dracula-network-bandwidth-show-interface true
+```
+
 #### network-ping options
 
 You can configure which server (hostname, IP) you want to ping and at which rate (in seconds). Default is google.com at every 5 seconds.

scripts/network_bandwidth.sh

@@ -1,51 +1,103 @@
 #!/usr/bin/env bash
 
-INTERVAL="1"  # update interval in seconds
+# INTERVAL is equal to 1s because we want to express the bandwidth in sec
+readonly INTERVAL=1
 
-network_name=$(tmux show-option -gqv "@dracula-network-bandwidth")
+# UPLOAD and DOWNLOAD index
+readonly UPLOAD=0
+readonly DOWNLOAD=1
+
+# SIZE index are the multiple of the unit byte and value the internationally recommended unit symbol in sec
+readonly SIZE=(
+  [1]='B/s'
+  [1024]='kB/s'
+  [1048576]='MB/s'
+  [1073741824]='GB/s'
+)
+
+# interface_get try to automaticaly get the used interface if network_name is empty
+interface_get() {
+  name="$(tmux show-option -gqv "@dracula-network-bandwidth")"
+
+  if [[ -z $name ]]; then
+    case "$(uname -s)" in
+    Linux)
+      if type ip >/dev/null; then
+        name="$(ip -o route get 192.168.0.0 | awk '{print $5}')"
+      fi
+      ;;
+    esac
+  fi
+
+  echo "$name"
+}
+
+# interface_bytes give interface name and signal tx/rx return Bytes
+interface_bytes() {
+  cat "/sys/class/net/$1/statistics/$2_bytes"
+}
+
+# get_bandwidth return the number of bytes exchanged for tx and rx
+get_bandwidth() {
+  upload="$(interface_bytes "$1" "tx")"
+  download="$(interface_bytes "$1" "rx")"
+
+  #wait the interval for Wait for interval to calculate the difference
+  sleep "$INTERVAL"
+
+  upload="$(bc <<<"$(interface_bytes "$1" "tx") - $upload")"
+  download="$(bc <<<"$(interface_bytes "$1" "rx") - $download")"
+
+  #set to 0 by default useful for non-existent interface
+  echo "${upload:-0} ${download:-0}"
+}
+
+# bandwidth_to_unit convert bytes into its highest unit and add unit symbol in sec
+bandwidth_to_unit() {
+  local size=1
+  for i in "${!SIZE[@]}"; do
+    if (($1 < i)); then
+      break
+    fi
+
+    size="$i"
+  done
+
+  local result="0.00"
+  if (($1 != 0)); then
+    result="$(bc <<<"scale=2; $1 / $size")"
+  fi
+
+  echo "$result ${SIZE[$size]}"
+}
 
 main() {
-  while true
+  counter=0
-  do
+  bandwidth=()
-    output_download=""
-    output_upload=""
-    output_download_unit=""
-    output_upload_unit=""
 
-    initial_download=$(cat /sys/class/net/$network_name/statistics/rx_bytes)
+  network_name=""
-    initial_upload=$(cat /sys/class/net/$network_name/statistics/tx_bytes)
+  show_interface="$(tmux show-option -gqv "@dracula-network-bandwidth-show-interface")"
+  interval_update="$(tmux show-option -gqv "@dracula-network-bandwidth-interval")"
 
-    sleep $INTERVAL
+  if [[ -z $interval_update ]]; then
-
+    interval_update=0
-    final_download=$(cat /sys/class/net/$network_name/statistics/rx_bytes)
-    final_upload=$(cat /sys/class/net/$network_name/statistics/tx_bytes)
-
-    total_download_bps=$(expr $final_download - $initial_download)
-    total_upload_bps=$(expr $final_upload - $initial_upload)
-
-    if [ $total_download_bps -gt 1073741824 ]; then
-      output_download=$(echo "$total_download_bps 1024" | awk '{printf "%.2f \n", $1/($2 * $2 * $2)}')
-      output_download_unit="gB/s"
-    elif [ $total_download_bps -gt 1048576 ]; then
-      output_download=$(echo "$total_download_bps 1024" | awk '{printf "%.2f \n", $1/($2 * $2)}')
-      output_download_unit="mB/s"
-    else
-      output_download=$(echo "$total_download_bps 1024" | awk '{printf "%.2f \n", $1/$2}')
-      output_download_unit="kB/s"
   fi
 
-    if [ $total_upload_bps -gt 1073741824 ]; then
+  while true; do
-      output_upload=$(echo "$total_download_bps 1024" | awk '{printf "%.2f \n", $1/($2 * $2 * $2)}')
+    if ((counter == 0)); then
-      output_upload_unit="gB/s"
+      counter=60
-    elif [ $total_upload_bps -gt 1048576 ]; then
+      network_name="$(interface_get)"
-      output_upload=$(echo "$total_upload_bps 1024" | awk '{printf "%.2f \n", $1/($2 * $2)}')
-      output_upload_unit="mB/s"
-    else
-      output_upload=$(echo "$total_upload_bps 1024" | awk '{printf "%.2f \n", $1/$2}')
-      output_upload_unit="kB/s"
     fi
 
-    echo "↓ $output_download $output_download_unit • ↑ $output_upload $output_upload_unit"
+    IFS=" " read -ra bandwidth <<<"$(get_bandwidth "$network_name")"
+
+    if [[ $show_interface == "true" ]]; then echo -n "[$network_name] "; fi
+    echo "↓ $(bandwidth_to_unit "${bandwidth[$DOWNLOAD]}") • ↑ $(bandwidth_to_unit "${bandwidth[$UPLOAD]}")"
+
+    ((counter = counter - 1))
+    sleep "$interval_update"
   done
 }
+
+#run main driver
 main