Question

How can I compare a variable in bash shell script to less than 1?

I did before, but I get ‘1: No such file or directory’

grep_result=`grep -r $ID . | wc -l`

echo $grep_result
# it said '1: No such file or directory'
if [ $grep_result < 1 ]; then
    echo "Wrong id.
    exit 1
fi

Answer 1

From bash’s perspective this means pipe the file called 1 into the $grep_result variable. You need to use the -lt operator in this case. (le stands for less than)

grep_result=`grep -r $ID . | wc -l`

echo $grep_result
# it said '1: No such file or directory'
if [ $grep_result -lt 1 ]; then
    echo "Wrong id.
    exit 1
fi