Random patronym with login

random_patronym_with_login.sh

#! /bin/bash

if [[ -n "$1" ]]; then
    N=$1
else
    N=1
fi
FEMININE_FIRSTS=feminine_firsts.txt
MASCULINE_FIRSTS=masculine_firsts.txt
LASTS=lasts.txt
for i in $(seq $N); do
    N=$(cat $FEMININE_FIRSTS $MASCULINE_FIRSTS | shuf -n 1)
    P=$(shuf -n 1 $LASTS)
    echo "$N,$P,$(echo ${N,,} | head -c 1)${P,,}"
done