Check if a condition is false

It is seems to be an easy question, I wonder why googling didn’t give anything helpful — nor in StackOverflow, nor in tutorials. I just need to check using bash that a condition is false.

Of what I found I tried

if ! [ 0==2 ]; then echo Hello; fi

and

if [ ! 0==2 ]; then echo Hello; fi 

none of them print Hello.

I found only two similar questions, but the end answer in both cases was restructured code to not use the “false” condition.

Answer

Do you mean:

if ! [ 0 == 2 ]; then
  echo Hello;
fi

You lacked space around the equality operator.

This might be the time to read http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html – especially the sections about if then else and operators. I usually have this open when I am writing scripts..