busybox-1.19.3/examples/var_service/ftpd/run

#!/bin/sh

#exec >/dev/null
exec 2>&1
exec </dev/null

user=www
user=root

exec \
env - PATH="$PATH" \
softlimit \
tcpsvd \
  -vE -l 0 -c 40 \
  0.0.0.0 21 \
setuidgid "$user" \
ftpd -vv -t10 /pub/ftpd_root