script to change vpn connection if slow vpn connection

andrew44 · 02-22-2014, 05:21 PM

I want to write a script to pick one of 2 vpn connections, I might add more but I need to get over my first hurdle which is why I'm pasting here.

As long as the connection is above 100 as calculated by the wget statement in line 3 all is good.

But if it drops to below 100 I get a message

./vpngood.sh: line 6: [: 81.2: integer expression expected

-------------------------------------------------------

#!/bin/bash
#My name is vpngood.sh
#set -x
AVERAGE=`wget -O /dev/null http://somewebsite.jpg 2>&1 | grep '\([0-9.]\+ [KM]B>
if [ $AVERAGE -gt 100 ]
then
echo "Average is above 100"
else
echo "Count is below than 100"
fi

-------------------------------------------------------
If I manually set Average to a number it works fine.

What am I doing wrong?

Thanks

catkin · 02-23-2014, 09:05 AM

Can you copy and paste the exact script? This line cannot be correct ...

Code:

AVERAGE=`wget -O /dev/null http://somewebsite.jpg 2>&1 | grep '\([0-9.]\+ [KM]B>

... because there is no closing ' and no closing `

When posting it, please use CODE tags (most easily done by posting in Advanced Mode and using the # button) to preserve indentation and let the code line up nicely.

What is the value of AVERAGE when it fails? Apparently it is not an integer so you could test whether it is an integer before testing its value:

Code:

if [[ $INTEGER =~ ^[0-9]+$ ]]; then
    if ((AVERAGE > 100 )); then
        echo "Average is above 100: $AVERAGE"
    else
        echo "Average is below or equal to 100: $AVERAGE"
    fi
else
    echo "Average is not a number: $AVERAGE"
fi

I have taken the liberty of using [[ ... ]] instead of [ ... ] because it is all round a better test for reasons explained here and (( ... )) instead of [ ... ] for the numeric test because the syntax is cleaner. You might also like to start using $( ... ) instead of ` ... ` for reasons explained here.

andrew44 · 02-23-2014, 11:25 AM

This is the script as it is at the moment. It works now, thanks for the pointers.

Code:

#!/bin/bash
#My name is vpngood.sh
#set -x
AVERAGE=$(wget -O /dev/null http://i.dailymail.co.uk/i/pix/2013/07/04/article-2355815-18AFDE11000005DC-143_306x955.jpg 2>&1 \
| grep '\([0-9.]\+ [KM]B/s\)'| awk '{print $3}'|sed 's/[!@#\$%^&*()]//g')
    if ((AVERAGE > 140 ));
    then
        echo "Average is greater than 140, its $AVERAGE"
else
        echo "Average is below 140, it's $AVERAGE ."
fi