Output n equal signs from a script
in [Shell]
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From: John Kelly on 18 Jun 2010 03:11 On Fri, 18 Jun 2010 00:32:52 -0400, Barry Margolin <barmar(a)alum.mit.edu> wrote: > Design your code well first, and optimize it if performance turns > out to be a problem. That's like saying, design your skyscraper well first, and if it collapses and kills a lot of people, then its performance turned out to be a problem. -- Web mail, POP3, and SMTP http://www.beewyz.com/freeaccounts.php
From: Barry Margolin on 18 Jun 2010 04:17 In article <2l6m165pl84cf1p5tg2ld2k7p0u803qgon(a)4ax.com>, John Kelly <jak(a)isp2dial.com> wrote: > On Fri, 18 Jun 2010 00:32:52 -0400, Barry Margolin <barmar(a)alum.mit.edu> > wrote: > > > Design your code well first, and optimize it if performance turns > > out to be a problem. > > That's like saying, design your skyscraper well first, and if it > collapses and kills a lot of people, then its performance turned out to > be a problem. Not even close. I'm not saying release the slow version and wait for people to complain. I'm saying that you write the program clearly, then start testing it. If performance is a problem, profile it, find the parts that are causing performance issues (probably only a small part of it), and optimize them. All the great programmers will agree with this. The aphorism I mentioned earlier is attributed to C.A.R. Hoare, and has been quoted by Knuth. If you're writing something where performance is so critical that you need to sacrifice clarify and portability, what the hell are you doing writing it as a shell script in the first place? -- Barry Margolin, barmar(a)alum.mit.edu Arlington, MA *** PLEASE post questions in newsgroups, not directly to me *** *** PLEASE don't copy me on replies, I'll read them in the group ***
From: Maxwell Lol on 18 Jun 2010 06:54 John Kelly <jak(a)isp2dial.com> writes: > On Fri, 18 Jun 2010 00:32:52 -0400, Barry Margolin <barmar(a)alum.mit.edu> > wrote: > >> Design your code well first, and optimize it if performance turns >> out to be a problem. > > That's like saying, design your skyscraper well first, and if it > collapses and kills a lot of people, then its performance turned out to > be a problem. Oh come on, now. shell scripts and human life? Are we going to refer to Nazis and Hitler next?
From: Martin Vaeth on 18 Jun 2010 07:56 John Kelly <jak(a)isp2dial.com> wrote: > On Thu, 17 Jun 2010 18:51:25 +0200, Janis Papanagnou > >>YMMV, but I consider a solution that runs on any modern shell to be preferable >>to one that uses bash'isms unnecessarily. > > I tend to favor efficiency over portability. Especially if efficiency is an issue, you should code according to the standard: Running your script with dash instead of bash will speed it up probably more than using some bashism. > Linux and bash are so > prevalent, they're nearly a de facto standard. dash is probably contained in any Linux distribution, and some install it even by default as /bin/sh
From: Sven Mascheck on 18 Jun 2010 08:32
Maxwell Lol wrote: > Oh come on, now. shell scripts and human life? > Are we going to refer to Nazis and Hitler next? .... while Seinfeld would've called some guys a "shell nazi" in this group long ago, ha! |