POSIX defines a line as: > 3.185 Line > A sequence of zero or more non-<newline> characters plus a terminating <newline> character. So a file with some chara

POSIX defines a line as: > 3.185 Line > A sequence of zero or more non-<newline> characters plus a terminating <newline> character. So a file with some characters but no trailing newline is reported by `wc -l` as having zero lines.