Name: in_input - query if a player is in input mode

Syntax:
	int in_input(object ob);

Description:
	The in_input efun returns whether a player is in input mode. This
	mode is normally indicated by a different prompt (as the default '>')
	and is used by the more command or the post office for writing mails.
	The input mode is normally started by the in_input efun.

	If a player is in input mode or is editing a file (see in_ed) you
	cannot start a new input_to until the player has left the last one.

	In-input with in_ed is good to find out if a person is busy and you
	should better not disturb him. The people command usually shows
	information produced from these efuns.

Return value:
	If the player is in input mode, 1 is returned, else 0.

Examples:
	is_in_input = in_input(this_player());

See also: efun/in_ed, efun/input_to, w/people