portlint makes a small set of sanity checks for port directory.
usage: portlint [-abctvN] [-B#] [port_directory]
-a additional check for scripts/* and pkg/*
-b warn $(VARIABLE)
-c committer mode
-v verbose mode
-t nit pick about use of spaces
-N writing a new port
-B# allow # contiguous blank lines (default: 1 line)