I’m unable to get numeric comparisons working:
echo "enter two numbers";
read a b;
echo "a=$a";
echo "b=$b";
if [ $a \> $b ];
then
echo "a is greater than b";
else
echo "b is greater than a";
fi;
The problem is that it compares the number from the first digit on, i.e., 9 is bigger than 10, but 1 is greater than 09.
How can I convert the numbers into a type to do a true comparison?
9 s
In Bash, you should do your check in an arithmetic context:
if (( a > b )); then
...
fi
For POSIX shells that don’t support (())
, you can use -lt
and -gt
.
if [ "$a" -gt "$b" ]; then
...
fi
You can get a full list of comparison operators with help test
or man test
.