What's going on with my 'if' comparison in bash?

Question

bash input:

if [[ 167 > 10800 ]]
then
    echo "I can't compare"
fi

bash output:

I can't compare

I guess the question is pretty obvious...

Answer 1

To quote from the bash(1) manual page:

When used with [[, the < and > operators sort lexicographically using the current locale.

So 167 is indeed greater than 10800 as 6 is a greater ASCII character than 0.

Answer 2

The > character doesn't work for the type of comparison you want. You have to use -gt:

if [[ 167 -gt 10800 ]]
then
    echo "I can't compare"
fi

And if you want to do a less-than comparison, you need to do -lt. To see what other options you need to do for comparison, look at the test manpage.

Answer 3

Use curved brackets for a true numeric comparison

if (( 167 > 10800 ))
then
    echo "I can't compare"
fi

Good summary here: http://fvue.nl/wiki/Bash:_Numeric_comparison