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Re: portable rand/srand across linux,windows,etc

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Ben Bacarisse <ben.usenet@bsb.me.uk> wrote:
> JohnF <john@please.see.sig.for.email.com> writes:
>> Sorry if the wrong ng (please suggest another).
>> I'm looking for robustly portable stdlib entry points
>> for rand()/srand() (e.g., or random()/srandom()),
>> particularly across linux gcc and windows
>> mingw and djgpp (and ms compilers).
>> That is, I want to distribute one source, without
>> a lot of pesky #ifdef's, to compile on all platforms.
>> Would also be nice if portable across everything
>> else from free/netbsd to vms/dec C, too, but linux
>> and windows are the biggies. Google shows various
>> occasional complaints about rand stuff not compiling and/or
>> not working on windows. I don't need anything particularly
>> good -- just naked eye random, so to speak. And if it's
>> easier to just cut-and-paste source from Numerical Recipes,
>> I'm okay with that, too.
> 
> rand and srand are documented in the C standard (and not only the most
> recent -- they date back to C90) so they are amongst the most portable
> functions you could call.  I can't imagine that there's a Windows C
> implementation without these (but I've been surprised before by
> Windows).
> 
> If you end up cut-and-pasting code, search the archives of this group
> for KISS.  George Marsaglia (sadly no longer with us) has posted several
> highly efficient PRNGs with very long periods here.  He was not a C
> expert, but there have been followups that have correctly portability
> issues where they've been spotted.  Here's a reference to one:
> Message-ID: <4dbd6e9c$0$12957$892e0abb@auth.newsreader.octanews.com>

Thanks, Eric and Ben. Yeah, I'd already distributed source using
srand()/rand(), and then came across a few google complaints about
mingw not having them. So I thought I'd double-check while the fan
was still clean (no problem emails yet). To cut-and-paste, by the way,
even my K&R 2nd ed (also, sadly, just recently no longer with us)
has a quick-and-dirty 10-line stdlib version on pg.46 that I probably
would've used. So it seems pretty standard even back to then.
-- 
John Forkosh  ( mailto:  j@f.com  where j=john and f=forkosh )

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portable rand/srand across linux,windows,etc JohnF <john@please.see.sig.for.email.com> - 2011-11-15 12:55 +0000
  Re: portable rand/srand across linux,windows,etc Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-15 08:01 -0500
  Re: portable rand/srand across linux,windows,etc Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-15 13:14 +0000
    Re: portable rand/srand across linux,windows,etc JohnF <john@please.see.sig.for.email.com> - 2011-11-15 13:46 +0000
      Re: portable rand/srand across linux,windows,etc Keith Thompson <kst-u@mib.org> - 2011-11-15 14:09 -0800
        Re: portable rand/srand across linux,windows,etc JohnF <john@please.see.sig.for.email.com> - 2011-11-16 03:45 +0000
          Re: portable rand/srand across linux,windows,etc Keith Thompson <kst-u@mib.org> - 2011-11-15 20:11 -0800

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