Re: [Help-bash] Brace expansions in if statement

[João Eiras]

>> Excerpts from Felipe Salvador's message of 2018-03-29 20:12:21 +0200:
>> > Hi list,
>> > I'm trying to make bash to expand a brace expansion in a if statement.
>> >
>> > So, I've
>> >
>> >        if [ "$GTTY" = tty{0..10} ]; then
>> >        msger=echo
>> >        else
>> >        msger=notify-send
>> >        fi
>> >

a) Use echo as a helper to expand inside expressions
b) bash has substring matching
c) mind the spaces

if [[ "$(echo " "tty{0..10}" ")" == *" $GTTY "* ]]; then
  msger=echo
else
  msger=notify-send
fi

But I'd simplify your expression to

if tty | cut -d'/' -f3 | grep -q '^tty[0-9]\+$'; then
 # ...
fi

>> > where $GTTY is $(tty | cut -d'/' -f3).

I'm on ubuntu, which tells me
$ tty
/dev/pts/2
$ tty | cut -d'/' -f3
pts

So I'm not entirely sure your approach is inter-operable, in case
that's an issue for you.