[Script] Check bandwidth distribution without leaving your terminal

[pyed]

Hi, Sometimes you really want to check who's draining your bandwidth on the network to yell at them or even block/throttle them , or maybe to know that your ISP is the cause of all your problems.

I usually find it hard to open the browser and go to /bandwidth_distribution.sh to see who's using all the bandwidth, so I wrote bandwidth_distribution.sh.

Code: Select all

#!/bin/bash

IP="192.168.1.1"

out=$(ssh root@${IP} "bw_get -i bdist1-download-minute-15 | awk 'FNR==NR{ a[\$3]=\$4; next } \$1 in a { \$1 = a[\$1] } { print }' /tmp/dhcp.leases -" | sort -gr -t' ' -k 2 | column -t | tr -s ' ')

# convert bytes to human readable form. e.g. 20456634 -> 19.51 MiB
bytesToHuman() {
    local L_BYTES="${1:-0}"
    local L_PAD="${2:-no}"
    local L_BASE="${3:-1024}"
    BYTESTOHUMAN_RESULT=$(awk -v bytes="${L_BYTES}" -v pad="${L_PAD}" -v base="${L_BASE}" 'function human(x, pad, base) {
         if(base!=1024)base=1000
         basesuf=(base==1024)?"iB":"B"

         s="BKMGTEPYZ"
         while (x>=base && length(s)>1)
               {x/=base; s=substr(s,2)}
         s=substr(s,1,1)

         xf=(pad=="yes") ? ((s=="B")?"%5d   ":"%8.2f") : ((s=="B")?"%d":"%.2f")
         s=(s!="B") ? (s basesuf) : ((pad=="no") ? s : ((basesuf=="iB")?(s "  "):(s " ")))

         return sprintf( (xf " %s\n"), x, s)
      }
      BEGIN{print human(bytes, pad, base)}')
    echo "$BYTESTOHUMAN_RESULT"
}

while read -r line; do
	host=$(echo "$line" | cut -d' ' -f1)
	bytes=$(echo "$line" | cut -d' ' -f2)
	human=$(bytesToHuman "$bytes")

	table+="$host,$human"
	table+=$'\n'
done <<< "$out"

echo "$table" | column -s',' -t | sed "s,MiB,$(tput setaf 1)&$(tput sgr0)," | sed '1,1{H;1h;d;};$G'

The script connects via SSH and executes a command that return the current minute's bandwidth usage for each client, sort and prettifies, then print.

You need SSH to be working, preferably using private key login AKA passwordless login, if you are experiencing slow SSH logins AKA it takes more than a second to connect, read my thread here, if you want to make connecting to your SSH even faster, Google SSH ControlMaster/ControlPersist.

Things to note

• This script meant to run on unix systems e.g. linux/macOS.
• If your router's IP is not 192.168.1.1, then change line 3.
• I'm not sure if this script will run on all Gargoyle installations.
• I'm sure there are so many ways to improve it.

[ispyisail]

Thanks