Re: Recomended tutoial(s) on doing arithmetic in Bash scripts

[<tomas@tuxteam.de>]

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On Sun, Mar 05, 2017 at 06:14:00PM +0000, GiaThnYgeia wrote:
> It is Sunday and I don't like Mondays
> tell me why
> 
> tomas@tuxteam.de:
> > Hm. Neither expr nor bc are bash, they are "external" binaries. If you
> > want to do arithmetic in bash, there's $((...)):
> > 
> >   tomas@rasputin:~$ echo $(( (3+4)/3 ))
> >   2
> 
> I see your 2 and raise you
> nosuchagency@bottomofthesea:~$ echo $(((3000000000+4000000000)/3))
> 2333333333
> 
> Infinitely inaccurate digital systems

:-)

Try GNU Guile: it'll happily fill your computer's memory with long integers:

  tomas@rasputin:~$ guile
  GNU Guile 2.0.13.5-458ae
  Copyright (C) 1995-2016 Free Software Foundation, Inc.
  
  Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
  This program is free software, and you are welcome to redistribute it
  under certain conditions; type `,show c' for details.
  
  Enter `,help' for help.
  scheme@(guile-user)> (expt 2 2)
  $1 = 4
  ; aha: that's the function we're looking for ;-)
  scheme@(guile-user)> (expt 2 400)
  $2 = 2582249878086908589655919172003011874329705792829223512830659356540647622016841194629645353280137831435903171972747493376

regards
- -- tomás
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