srodowisko_programisty/lab1/6.bash

#!/usr/bin/env bash

for word in $(grep -Roh '\w*' "$1" | sort | uniq)
do
    occurences=$(grep -REn ".*\b$word\b.*\b$word\b.*" "$1")
    [ -n "$occurences" ] && printf '%s:\n%s\n' "$word" "$occurences"
done