question about getpass

[mark.umcp-cs%udel-relay at sri-unix.UUCP]

From:  Mark Weiser <mark.umcp-cs at udel-relay>

	In the documentatin of getpass(3) it says that the routine
	reads a password from standard input if it connot open
	"/dev/tty."  How can one make /dev/tty unopenable?  Thanks
	for any suggestions or solutions.

An easy way to make /dev/tty unopenable is for someone to open it exclusive
mode.  This works for everyone but the superuser, who can always
open everything (at least in 4.1bsd).  I haven't found any way around the 
superuser exception.
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