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From: dce@Solbourne.COM (David Elliott)
Newsgroups: comp.unix.wizards
Subject: while true (was Re: Must UNIX be a memory hog?)
Keywords: TZ, uucp LCK... files
Message-ID: <1197@marvin.Solbourne.COM>
Date: 19 May 89 17:14:57 GMT
References: <159@zebra.UUCP> <1608@auspex.auspex.com> <2@minya.UUCP>
Reply-To: dce@Solbourne.com (David Elliott)
Organization: Solbourne Computer Inc., Longmont, Colorado
Lines: 23

In article <2@minya.UUCP> jc@minya.UUCP (John Chambers) writes:
>On this system, as on several others, I've replaced /bin/true and /bin/false
>with executables (which will be left as an exercise for the reader, since
>posting them would be an intellectual insult to any True Unix Wizards ;-).
>I've verified that the result is a measurable speedup in "while true"
>loops, due to the elimination of the shell startup to run an empty script.
>But this isn't much of a big deal, since such loops are rather rare.

I don't know about "rather rare", since I have a number of big
shell scripts that use "infinite" while loops.

The simplest speedup is to use a builtin command that returns
true; specifically ":".  In other words, the fastest "while true"
loop is actually

	while :
	do
		...
	done

-- 
David Elliott		dce@Solbourne.COM
			...!{boulder,nbires,sun}!stan!dce