A script that handles backups of your local bridge settings.

bridge_backup.sh

#!/bin/sh

FILE="$2"

if ( [ "$1" = "backup" ] && [ "$FILE" != "" ] ); then
	# backup
	brctl show | awk 'NR > 1 && $4 != "" { print $1 " " $4; last=$1; } NR > 1 && $2 == "" { print last " " $1; }' > "$FILE"

	echo "Done"

elif ( [ "$1" = "restore" ] && [ "$FILE" != "" ] ); then
	# restore
	if [ ! -f "$FILE" ]; then
		echo "No such file."
		exit 1
	fi

	echo "Executing:"
	cat "$FILE" | awk '{ print "echo brctl addif " $1 " " $2 | "sh" }'

	do_exec=""

	while ( [ "$do_exec" != "y" ] && [ "$do_exec" != "n" ] ); do
		echo "[y]es [n]o?"
		read do_exec

		if ( [ "$do_exec" != "y" ] && [ "$do_exec" != "n" ] ); then
			echo "Invalid input"
		fi
	done

	if [ "$do_exec" = "n" ]; then
		echo "I will do noting"
		exit 0
	fi

	cat "$FILE" | awk '{ print "brctl addif " $1 " " $2 | "sh" }'

	echo "Done"

else
	# error
	echo "Usage: $0 [backup|restore] [file]"
	exit 1
fi