# yesno() -- prompt user to accept yes or no
# Usage: yesno [prompt msg]
#
# Example:
#
# while ! yesno "sila taip yes"; do
#	echo "yes ditaip";
# done
#

yesno() {
	[ $# -eq 1 ] || return 1;
	local _prompt="$1";
	local _ANS="";
	read -p "${_prompt} [yes/no]: " _ANS;
	while [ "$_ANS" != "yes" ] && [ "$_ANS" != "no" ]; do
		read -p "Please enter 'yes' or 'no': " _ANS;
	done;
	[ "$_ANS" = "yes" ] && return 0;
	return 1;
}