grep/regex can't find accented word

Question

I\'m trying mount a regex that get some words on a file where all letters of this word match with a word pattern.

My problem is, the regex can\'t find accented words

Answer 1

Try as @dule said, but with LANG=en_US.iso88591:

cat input/words.txt | LANG=en_US.iso88591 grep '^[éra]\{1,4\}$' > output/words_era.txt