Check if a user is in a group

Question

I have a server running where I use php to run a bash script to verify certain information of a user. For example, I have a webhosting server set up, and in order to be able to

Answer 1

Bash single line:

[[ " $(groups) " =~ ' spark ' ]] && echo 'Is in group'

Bash multi line:

if [[ " $(groups) " =~ ' spark ' ]]; then
    echo 'Is in group'
fi