Bash: Integer expression expected [duplicate]

问题:

This question already has answers here:

How to compare two floating point numbers in Bash? [duplicate] (17 answers)

Closed 4 years ago.

I'm trying to perform simple math, to check if a variable is greater or equal to "1.5" but I'm getting [: 2.41: integer expression expected

Code:

reSum=$(expr "scale=1;555/230" | bc)

if [ $reSum -ge "1.5" ]; then
...
fi

How can I do floating-point comparisons in shell script?

回答1:

if echo 555 230 | awk '{exit $1/$2 >= 1.5 ? 0 : 1}'
then
  # ...
fi

回答2:

Edit:

The shortest solution that works for me:

reSum=$(expr "scale=1;555/230" | bc)

if (( `echo $reSum'>='1.5 | bc` )); then
  # anything
fi

As pointed out by shellter, [ $(expr "$reSum > 1.5" | bc) ] actually does a lexicographic comparison. So, for example, expr "2.4 > 18 | bc" // =>0.

However, (( `echo $reSum'>='1.5 | bc` )) does floating point comparison rather than strings.