Question

Given a file in UTF-8, containing characters in various languages, how can I obtain a count of the number of unique characters it contains, while excluding a select number of symbols (e.g.: “!”, “@”, “#”, “.”) from this count?

Answer 1

Using a Perl one-liner:

echo -e "aba\ncfg!ഡ.#g" | perl -C7 -ne 'for(split(//)){if ($_ !~ /[!@#.]/) { print $_."\n"}}' | sort | uniq | wc -l

OUTPUT 7

If you want to ignore newline:

echo -e "aba\ncfg!ഡ.#g" | perl -C7 -ne 'for(split(//)){if ($_ !~ /[!@#.\n]/) { print $_."\n"}}' | sort | uniq | wc -l

OUTPUT 6