According to POSIX the fold utility is intended to fold characters, with the '-b' flag used to fold bytes instead. However, GNU fold will always fold bytes. Compare: $ echo '$$$$$$$$' | fold -w 4 $ echo '££££££££' | fold -w 4 The former will produce 2 lines, while the latter will produce 4, since the UTF-8 character '£' consists of 2 bytes. The behaviour is identical when the '-b' flag is used. FreeBSD's fold treats multibyte characters correctly.