Date: Thu, 28 Jun 2001 23:32:37 -0400 From: Pete Fritchman <petef@databits.net> To: Dave Tweten <tweten@nas.nasa.gov> Cc: freebsd-doc@freebsd.org Subject: Re: Fw: Re: Bourne Shell Syntax Wierdness Message-ID: <20010628233237.A81983@databits.net> In-Reply-To: <200106290209.f5T29Hu01819@gilmore.nas.nasa.gov>; from tweten@nas.nasa.gov on Thu, Jun 28, 2001 at 07:09:16PM -0700 References: <200106290209.f5T29Hu01819@gilmore.nas.nasa.gov>
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++ 28/06/01 19:09 -0700 - Dave Tweten: | > The sh man page says that the two operators "||" and "&&" have the same | > precedence. [ snip ] | > So I don't understand why | > | > true || true && echo Oops! | > | > prints "Oops!" "They have the same precedence." In math, "+" and "-" have the same precedence. So, if you have 1 + 2 + 3, you evaluate 1 + 2, then you evaulate that result + 3. true || true && echo Oops! you first take 'true || true' -- you end up with true. you then eval '&& echo Oops!' with the result of 'true || true' (true). true always exits sucessfully, so the command after && is executed and you see 'Oops!' Does this sound right? It makes sense in my head, but I'm not sure if I'm explaining it right. | > | > This is apparently not a bug in FreeBSD sh, because IRIX, IRIX64, and SunOS | > Bourne/Korn shells work the same way, but it certainly runs counter to my | > ability to read English and the contents of the man page. | > -pete -- Pete Fritchman <petef@databits.net> Databits Network Services, Inc. <http://databits.net>; finger petef@databits.net for PGP key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-doc" in the body of the message
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