Question

Trying to compare input to a file containing alert words,

read MYINPUT
alertWords=( `cat "AlertWordList" `)
for X in "${alertWords[@]}"
do
# the wildcards in my expression do not work
if [[ $MYINPUT =~ *$X* ]] 
then
    echo  "#1 matched"
else
    echo  "#1 nope"
fi
done

Answer 1

I’d avoid =~ here because as FatalError points out, it will interpret $X as a regular expression and this can lead to surprising bugs (especially since it’s an extended regular expression, so it has more special characters than standard grep syntax).

Instead, you can just use == because bash treats the RHS of == as a globbing pattern:

read MYINPUT
alertWords=($(<"AlertWordList"))
for X in "${alertWords[@]}"
do
# the wildcards in my expression do work :-)
if [[ $MYINPUT == *"$X"* ]] 
then
    echo  "#1 matched"
else
    echo  "#1 nope"
fi
done

I’ve also removed a use of cat in your alertWords assignment, as it keeps the file reading inside the shell instead of spawning another process to do it.