Path: utzoo!attcan!uunet!lll-winken!ames!ncar!tank!mimsy!chris
From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.unix.wizards
Subject: Re: script & lock
Message-ID: <15399@mimsy.UUCP>
Date: 11 Jan 89 05:12:03 GMT
References: <17972@adm.BRL.MIL> <596@cf-cm.UUCP>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 23

In article <596@cf-cm.UUCP> sme@computing-maths.cardiff.ac.uk
(Simon Elliott) writes:
>... A program run in script is attached to [a] pseudo terminal so
>getlogin() returns a pointer to the null string entry from utmp.
>Getlogin returns the NULL pointer only if it called from a process
>which is NOT attached to any terminal (even a pseudo one).

Not so.  If I may quote from getlogin():

	#if defined(LIBC_SCCS) && !defined(lint)
	static char sccsid[] = "@(#)getlogin.c	5.3 (Berkeley) 5/9/86";
	#endif LIBC_SCCS and not lint

	...
		if (ubuf.ut_name[0] == '\0')
			return (0);
	...
		return (ubuf.ut_name);

I believe *getlogin()==0 may be true under some broken Unixes.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris