#bashing multiple expressions

So to do a couple of cool stuff in bash use the [[ many-expressions ]] brackets not the [ expression ]
For example one can do multiple expressions

if [[ foo || bar || baz ]] ; then
  ...
fi

For more info look at this stackoverflow

if elif else fi #bashing about

When running a webservice one needs a couple of good scripts that make work easier.
I have been using bash scripts for just that..
Bash is one of the weirdest languages i have had to learn...stuff isn't that straight forward. I hade to google this stuff up

If [ conditional expression1 ]
then
 statement1
 statement2
 .
elif [ conditional expression2 ]
then
 statement3
 statement4
 .
.
.
else
 statement5
fi

I wont take all the credit, I got the info from HERE

adding stuff in bash

I just stumbled on a how to add stuff in bash

total=`expr $val_1 + $val_2 + $val_3`