#!/usr/bin/env bash
# Usage:
# Keep editing $u and $p and in a second terminal execute:
#    while :; do bash sqli.sh; sleep 1; done

main() {
    u='hans" or 1=1; --'
    p='p@ssw0rd'

    echo "SELECT * FROM user WHERE user = \"$u\" AND password = \"$p\";" | sed 's/--.*//'
}

main