View unicode codepoints for all letters in file on bash

file="some-file.txt"

perl -C -ne 'for (split //) {printf "U+%04X %s\n", ord, $_}' "$file" | sort -u
iconv -f utf8 -t utf32le "$file" | hexdump -v -e '"U+%04X\n"'        | sort -u
while IFS= read -d $'\000' -n 1 x; do printf 'U+%04X %s\n' "'$x" "$x"; done < "$file" | sort -u