I’ve got the following script:

#!/bin/bash

if [[ ${DISABLE_WORK} -ne "0" ]];
then
    echo "exiting"
    exit 0
fi

echo "doing something"

The output is:

case 1:
$ DISABLE_WORK=1 ./if.sh 
exiting

case 2:
$ DISABLE_WORK=2 ./if.sh 
exiting

case 3:
$ DISABLE_WORK=0 ./if.sh 
doing something

case 4:
$ ./if.sh 
doing something

I searched the documentation and still can not figure out why case 4 produces ‘doing something’ instead of ‘exiting’. Could someone explain, please?