/usr/bin/check-sendfile
/usr/bin/fetchfile
/usr/bin/pussy
/usr/bin/receive
/usr/bin/sendfile
/usr/bin/sendmsg
/usr/bin/sfconf
/usr/bin/utf7decode
/usr/bin/utf7encode
/usr/bin/wlock
/usr/sbin/sendfiled
You may install this package on Debian with
apt-get
install sendfile