This is a little script that I wrote for work to monitor the bandwidth being consumed on a server. We have a monitoring application already, but I couldn't easily get the other data I needed using it. This script uses the transmitted and received bytes readout from the ifconfig command.


We are looking to monitor our Elluminate Live servers, and I wanted the bandwidth information correlated with date, time, rooms in use, current users connected, and CPU load info. Most of that information was available with simple shell calls, or mysql commands, but the bandwidth was elusive. I eventually settled on writing the script myself so that it would output the incoming and outgoing bps that I needed for the logs.

I later added a pretty printing option that will give you a readable summary as there are many times in the past, I needed something quick and simple to tell me what is going on on the server.


  • Linux
  • Perl 5 (Not sure which version, might even run on earlier versions. I'm running 5.10.1)

The Script

# Prints out the bandwidth for a xx second sample in bps.
# Also prints detailed information with the -p switch.
# By: Thomas Hawkins  Date: Jan. 27, 2011
# incoming bps,outgoing bps
use strict;
use warnings;
sub usage(){
	print "Bandwidth Checker Usage Info\n";
	print "==================================\n";
	print "Flags:\n";
	print "-p Print pretty output\n";
	print "-s Print csv output (incoming bps, outgoing bps). Ex: 5042,239\n";
	print "-h Print this page\n";
	print "Optional: -i or --interface={interface} - An Interface Name. Ex: -i=eth0\n";
	print "Optional: -t or --time={seconds} - The number of seconds to monitor. Ex: -t=15\n";
	print "Example: perl -p -i=eth0 -t=15\n";
$time = 15;
$interface = 'eth0';
$mode = 0;
use Getopt::Long;
GetOptions("s"=> \$simple,
           "p"=> \$pretty,
           "h"=> \$help,
           "t:i"=> \$time,
           "time:i"=> \$time,
           "i:s"=> \$interface,
           "interface:s"=> \$interface);
	#Prints Usage Info
	$mode = 0;
	$mode = 1;
#Gets a line indicating the current usage.
$result = `ifconfig $interface | grep "RX bytes"`;
#strip it into variables for recieved and transmitted
$result =~ /\s*RX bytes:(\d*).*TX bytes:(\d*).*/;
#This converts the bytes to bits.
$initialrx = $1 * 8;
$initialtx = $2 * 8;
#wait x seconds and run the command again.
#Gets a line indicating the current usage.
$result = `ifconfig $interface | grep "RX bytes"`;
$result =~ /\s*RX bytes:(\d*).*TX bytes:(\d*).*/;
#This converts the bytes to bits.
$finalrx = $1 * 8;
$finaltx = $2 * 8;
#now print out the results
#print 'RX: ' . $finalrx . ' | ' . $initialrx;
#print 'TX: ' . $finaltx . ' | ' . $initialtx;
$differencerx = ($finalrx - $initialrx) / $time;
$differencetx = ($finaltx - $initialtx) / $time;
if($mode == 0){
	print $differencerx . ',' . $differencetx;
elsif($mode == 1){
	$kbitpsrx = $differencerx / 1024;
	$kbitpstx = $differencetx / 1024;
	$KBpsrx = $differencerx / 1024 / 8;
	$KBpstx = $differencetx / 1024 / 8;
	$kbitrx = ($finalrx - $initialrx) / 1024;
	$kbittx = ($finaltx - $initialtx) / 1024;
	$KBrx = ($finalrx - $initialrx) / 1024 / 8;
	$KBtx = ($finaltx - $initialtx) / 1024 / 8;
	print "Monitored traffic on interface $interface for $time seconds:\n";
	print "Incoming: $kbitrx kbit ($KBrx KB) Average: $kbitpsrx kbps ($KBpsrx KBps)\n";
	print "Outgoing: $kbittx kbit ($KBtx KB) Average: $kbitpstx kbps ($KBpstx KBps)\n";
scripts/bandwidth.txt · Last modified: 2011/01/27 13:54 by cornmaster
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