#!/bin/sh -e
#
#    network: calculate the network up/down rates
#
#    Copyright (C) 2008 Canonical Ltd.
#    Copyright (C) 2011-2014 Dustin Kirkland
#
#    Authors: Dustin Kirkland <kirkland@byobu.org>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, version 3 of the License.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

__network_detail() {
	get_network_interface; local interface="$_RET"
	LC_ALL=C /sbin/ip addr show "$interface" | $BYOBU_SED 's/\s*$//'
}

__network() {
	get_network_interface; local interface="$_RET"
	local x1=0 x2=0 tx1=0 i= t= unit= symbol= cache= rate=
	status_freq network
	t="$_RET"
	# By default, we won't bug the user with the display of network traffic
	# below NETWORK_THRESHOLD in kbps; override in $BYOBU_CONFIG_DIR/status
	[ -n "$NETWORK_THRESHOLD" ] || NETWORK_THRESHOLD=20
	for i in up down; do
		unit="kb"
		case $i in
			up) symbol="$ICON_UP" ;;
			down) symbol="$ICON_DN" ;;
		esac
		cache="$BYOBU_RUN_DIR/cache.$BYOBU_BACKEND/network.$i"
		[ -r "$cache" ] && read x1 < "$cache" || tx1=0
		local iface rbytes rpackets rerrs rdrop rfifo rframe rcompressed rmulticast tbytes tpackets terrs tdrop tfifo tcolls tcarrier tcompressed
		cat /proc/net/dev > "$cache".dev
		while read iface rbytes rpackets rerrs rdrop rfifo rframe rcompressed rmulticast tbytes tpackets terrs tdrop tfifo tcolls tcarrier tcompressed; do
			case "$iface" in
				${interface}:)
					[ "$i" = "up" ] && x2=${tbytes} || x2=${rbytes}
					break;
				;;
				${interface}:*)
					# Interface and tbytes got munged together
					[ "$i" = "up" ] && x2=${rmulticast##*:} || x2=${iface##*:}
					break;
				;;
			esac
		done < "$cache".dev
		printf "%s" "$x2" > "$cache"
		rate=$((8*($x2 - $x1) / $t / 1024))  # in kbps
		[ "$rate" -lt 0 ] && rate=0
		if [ $rate -gt $NETWORK_THRESHOLD ]; then
			case "$NETWORK_UNITS" in
				bytes)
					rate=$(($rate/8))
					if [ "$rate" -gt 1048576 ]; then
						fpdiv "$rate" 1048576 1
						rate=${_RET}
						unit="GB/s"
					elif [ "$rate" -gt 1024 ]; then
						fpdiv "$rate" 1024 1
						rate=${_RET}
						unit="MB/s"
					else
						unit="kB/s"
					fi
				;;
				*)
					# Default to bps
					# Why 1000 and not 1024?  http://en.wikipedia.org/wiki/Data_rate_units
					if [ "$rate" -gt 1000000 ]; then
						fpdiv "$rate" 1000000 1
						rate=${_RET}
						unit="Gb"
					elif [ "$rate" -gt 1000 ]; then
						fpdiv "$rate" 1000 1
						rate=${_RET}
						unit="Mb"
					fi
				;;
			esac
			[ -n "$rate" ] || continue
			color b m w; printf "%s%s" "$symbol" "$rate"; color -; color m w; printf "%s" "$unit"; color --
		else
			rm -f "$BYOBU_RUN_DIR/status.$BYOBU_BACKEND/network"*
		fi
	done
}

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