Date: Sun, 21 Feb 1999 23:54:24 -0500 (EST) From: Mikhail Teterin <mi@kot.ne.mediaone.net> To: current@freebsd.org Subject: Re: sh(1) -- exec vs. fork Message-ID: <199902220454.XAA19404@kot.ne.mediaone.net> In-Reply-To: <199902200258.AA26119@waltz.rahul.net> from Rahul Dhesi at "Feb 19, 1999 06:58:32 pm"
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So, should I send-pr? -mi Rahul Dhesi once stated: =Many years ago I posted a shell script to Usenet in which I prepended a =line with 'exec', in an attempt to avoid having a shell process hanging =around doing a wait(). David Korn himself (of Korn shell fame) =responded saying this was not necessary, as the shell would do exec() =anyway. = =I check with trace() on a Sun and he seemed to be right. This was for =the classic Bourne shell many years ago. = =But I just checked /bin/sh on 3.1-RELEASE with ktrace and the above does =not seem to be true. I get drastically different traces for = = #! /bin/sh = exec /bin/pwd = =and = = #! /bin/sh = /bin/pwd = =Rahul = => Date: Fri, 19 Feb 99 11:43:59 EST => From: Mikhail Teterin <mi@misha.cisco.com> => To: current@freebsd.org => Message-Id: <199902191644.LAA08791@misha.cisco.com> => Subject: sh(1) -- exec vs. fork => Reply-To: mi@aldan.algebra.com = => I just finished going through a couple of crontabs prepending the => command-lines with ``exec'', when it hit me. => => Can shell itself recognize, there will be no more commands and just => proceed to exec without forking? What would this break? =... = = =To Unsubscribe: send mail to majordomo@FreeBSD.org =with "unsubscribe freebsd-current" in the body of the message = To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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