Bash: Monitoring a file until a string is found

The script will wait for the string "Server Started" appear in logfile.log and then continue the execution

    #!/usr/bin/env bash

    start_server.sh > logfile.log &

    # waiting for the server to start...
    ( tail -f -n0 logfile.log & ) | grep -q "Server Started"

    echo "Server is running"

Source:
https://superuser.com/questions/270529/monitoring-a-file-until-a-string-is-found