explicit_lib_depends.sh shows you the current explicit dependency list of

libs for a given installed port, e.g.:
	# ./explicit_lib_depends.sh gnome-vfs-2.18.1_2
	USE_GETTEXT=yes
	USE_GNOME+=gconf2
	USE_GNOME+=glib20
	USE_GNOME+=gnomevfs2
	USE_GNOME+=libxml2
	USE_GNOME+=orbit2
	USE_ICONV=yes
	avahi-client:net/avahi
	avahi-common:net/avahi
	avahi-glib:net/avahi
	dbus-1:devel/dbus
	dbus-glib-1:devel/dbus-glib

Tools/scripts/explicit_lib_depends.sh

@@ -0,0 +1,115 @@
+#!/bin/sh
+
+#
+# Copyright (C) 2007 Alexander Leidinger <netchild@FreeBSD.org>.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+
+# $FreeBSD$
+
+#
+# The purpose of this script is to give the real dependency list of a
+# currently installed port.
+#
+
+print_usage() {
+	echo "Usage: $0 [-b base ...] port_name ..."
+	echo "Example: $0 -b /usr/local -b /space/porttest gnome-vfs-2.18.1_2"
+}
+
+args=$(getopt b:h $@)
+if [ $? -ne 0 ]; then
+	print_usage
+	exit 2
+fi
+
+set -- ${args}
+for arg; do
+	case "${arg}" in
+	-b)
+		bases="${bases} -b $2"
+		shift; shift
+		;;
+	-h)
+		print_usage
+		exit 0
+		;;
+	--)
+		shift
+		break
+		;;
+	esac
+done
+
+if [ -z "$1" ]; then
+	print_usage
+	exit 2
+fi
+
+if [ -z "${PORTSDIR}" ]; then
+	PORTSDIR=$(make -f /etc/make.conf -V PORTSDIR)
+fi
+
+if [ -z "${PORTSDIR}" -o ! -d "${PORTSDIR}" ]; then
+	PORTSDIR=/usr/ports
+fi
+
+if [ -z "${PKG_DBDIR} ]; then
+	PKG_DBDIR=$(make -f /etc/make.conf -V PKG_DBDIR)
+fi
+
+if [ -z "${PKG_DBDIR} -o ! -d "${PKG_DBDIR}" ]; then
+	PKG_DBDIR=/var/db/pkg
+fi
+
+for i in $@; do
+	if [ -d "${i}" ]; then
+		current_port="${i}"
+	else
+		if [ -d "${PKG_DBDIR}/${i}" ]; then
+			current_port="${PKG_DBDIR}/${i}"
+		fi
+	fi
+
+	awk '
+		/^@cwd / {
+			CWD=$2;
+			if (CWD == ".") {
+				exit 0;
+			}
+		}
+
+		/^bin\// {
+			printf "%s/%s\n", CWD, $1;
+		}
+
+		/^lib\// {
+			printf "%s/%s\n", CWD, $1;
+		}
+	' < ${current_port}/+CONTENTS | \
+		xargs ${PORTSDIR}/Tools/scripts/neededlibs.sh | \
+		xargs ${PORTSDIR}/Tools/scripts/resolveportsfromlibs.sh ${bases}
+
+ 
+done | sort -u