Question

In shell script how can we compare (integer and floating point) ,(flaoting point and floating point),(floating point and integer),(integer and integer) with only one if condition.

i have few examples like

 set X=3.1
  set Y=4.1
  if [ $X < $Y ] then
    echo "wassup"
  endif

But running the above from cron job doesnt seem to work.

Answer 1

The way to carry out floating point operations in bash is to use bc which is available on almost all linux distributions.

# bc will return 0 for false and 1 for true
if [ $(echo "23.3 > 7.3" | bc) -ne 0 ] 
then 
  echo "wassup"
fi

There’s a good article available on linux journal about floating point math in bash using bc.