How to check if a variable contains a string

string="this string contains a test substring"

if [[ "$string" == *test* ]]
then
        print "substring found"
fi 

ZSH substr

One handy shortcut for getting all the characters except the first 2:

SHORTSTRING=$LONGSTRING[3,-1]

The negative offset is relative to the end of the string.

ZSH Tricks

Useful links for ZSH:

ZSH tricks
ZSH lovers