This script sets or removes the Dropbox ignored flag (the "com.dropbox.ignored" attribute) on a path.

dropbox_ignore.sh

#!/bin/sh
#
# This script sets or removes the Dropbox ignored flag (the
# "com.dropbox.ignored" attribute) on a path.
#
# Author: Caleb P. Burns
# License: CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
# Version: 1.0.0
# Created: 2020-07-18
# Updated: 2020-07-18
#

if [ "$1" = '-h' ] || [ "$1" = '--help' ] || [ "$#" -lt 2 ]; then
	echo "Usage: $0 [-h] { -s | -r } <path>"
	echo
	echo 'Set or remove the Dropbox ignored flag ("com.dropbox.ignored") on a path.'
	echo
	echo 'Arguments:'
	echo '  -g <path>   Get the flag from the file or directory path.'
	echo '  -s <path>   Set the flag of the file or directory path.'
	echo '  -r <path>   Remove the flag from the file or directory path.'
	echo '  -h, --help  Show this help message and exit.'
	exit 1
fi

if [ "$1" = '-g' ]; then
	attr -g com.dropbox.ignored "$2"
elif [ "$1" = '-s' ]; then
	attr -s com.dropbox.ignored -V 1 "$2"
elif [ "$1" = '-r' ]; then
	attr -r com.dropbox.ignored "$2"
else
	echo "Invalid option: '$1'"
	exit 1
fi