Using a tool called iftop we can monitor bandwidth usage via command line on Linux. But here we will create our own shell script to monitor bandwidth usage. The idea is to read rx_bytes and tx_bytes files inside /sys/class/net/[interface]/statistics/ folder.
Create netspeed script in /usr/local/bin/ and copy and paste below script.
# nano /usr/local/bin/netspeed
Script content:
#!/bin/bash if [ -z '$1' ]; then echo echo usage: $0 network-interface echo echo e.g. $0 eth0 echo exit fi IF=$1 while true do R1=`cat /sys/class/net/$1/statistics/rx_bytes` T1=`cat /sys/class/net/$1/statistics/tx_bytes` sleep 1 R2=`cat /sys/class/net/$1/statistics/rx_bytes` T2=`cat /sys/class/net/$1/statistics/tx_bytes` TBPS=`expr $T2 - $T1` RBPS=`expr $R2 - $R1` TKBPS=`expr $TBPS / 1024` RKBPS=`expr $RBPS / 1024` echo 'tx $1: $TKBPS kb/s rx $1: $RKBPS kb/s' done
Exit nano by typing Ctrl-X and press Y.
Change file mode into executable.
# chmod 775 /usr/local/bin/netspeed
Run the script:
# netspeed eth0 tx eth0: 26 kb/s rx eth0: 849 kb/s tx eth0: 37 kb/s rx eth0: 1246 kb/s tx eth0: 33 kb/s rx eth0: 1077 kb/s tx eth0: 37 kb/s rx eth0: 1250 kb/s tx eth0: 33 kb/s rx eth0: 1077 kb/s tx eth0: 31 kb/s rx eth0: 1043 kb/s
Source: madmadmod
