[SOLVED] How to compare a decimal variable with a number?

massy · 03-03-2014, 05:00 AM

tempr in my code is a decimal number like 23.8!
I want to check if it is less than -20 or great than 50 or not! my

Code:

if [ "$hour" != "$ch" ] || [ "$min" -lt $((cm-10)) ] || [ "$min" -gt $(($cm+10)) ] || [ $(echo "$tempr < -20" | bc -l ) ] || [ $(echo "$tmepr > 50" | bc -l ) ]
        then

NevemTeve · 03-03-2014, 05:18 AM

Try it in little steps:

step #1:

Code:

NUM=3.212; INT=${NUM%.*}; echo $INT
if [ $INT -lt 4  -a $INT -ge 2 ]; then
    echo "so far so good"
fi;

Ramurd · 03-03-2014, 05:43 AM

The problem is the if statement with a lot of reverse logic in it; if one of the statements evaluates to 'true', it will stop evaluating the rest of the statements; Question could also be: which statement to evaluate.

Code:

if [ "$hour" != "$ch" ] 
then
...
fi

So, if $hour equals $ch, the next test has to be evaluated, otherwise it is already true and doesn't become more or less true; So be careful linking all those tests together.

Then again, for the original question posted, bc has a good thing for you:

Code:

cur_temp="20.5"
tst_temp="20"
if [ $(echo "$cur_temp > $tst_temp" | bc -l) ]
then
     echo "It's more than 20."
else
     echo "It's less than 20."
fi