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From: keith@motel6.UUCP (Keith Packard)
Newsgroups: net.unix-wizards
Subject: Re: Conventional daemons
Message-ID: <203@motel6.UUCP>
Date: Mon, 24-Mar-86 15:52:14 EST
Article-I.D.: motel6.203
Posted: Mon Mar 24 15:52:14 1986
Date-Received: Wed, 26-Mar-86 06:47:39 EST
References: <261@bu-cs.UUCP> <328@hadron.UUCP>
Reply-To: keith@motel6.UUCP (Keith Packard)
Organization: 5440 SE 41st, Portland, OR
Lines: 19

In article <261@bu-cs.UUCP> ccc@bu-cs.UUCP (Cameron Carson) writes:
>	int s;
>	for (s = 0; s < SOME_NUM; s++)
>		(void) close(s);
>	(void) open("/",0);
>	(void) dup2(0,1);
>	(void) dup2(0,2);
>My question is: why open "/" ?  Why not open something a little
>less vital like, say, /dev/null?

Well, I suspect the answer to this lies in the dim dark past when unix
ran on small machines.  The inode for "/" is always in memory, the
inode for "/dev/null" is only in memory when it is referenced.  So,
opening "/" instead of "/dev/null" will not cause another inode-table
entry to be filled up.  Useful when your system only has 50 or so
incore inodes, considering that the daemon will *always* be running.

Keith Packard
...!tektronix!reed!motel6!keith