I realized after the fact, that looking at some of the different ways
you can write numbers in perl.
$n = 1234; # decimal integer
$n = 0b1110011; # binary integer
$n = 01234; # octal integer
$n = 0x1234; # hexadecimal integer
$n = 12.34e-56; # exponential notation
$n = "-12.34e56"; # number specified as a string
$n = "1234"; # number specified as a string
http://man.openbsd.org/perlnumber
On Tue, Jul 21, 2020 at 05:24:34PM -0700, Andrew Hewus Fresh wrote:
> On Tue, Jul 21, 2020 at 07:10:34PM -0500, Edgar Pettijohn wrote:
> > I was playing around with the hex function in perl. So naturally I
> > started with:
> >
> > perldoc -f hex
> >
> > Which showed me a few examples namely the following:
> >
> > print hex '0xAf'; # prints '175'
> > print hex 'aF'; # same
> > $valid_input =~ /\A(?:0?[xX])?(?:_?[0-9a-fA-F])*\z/
> >
> > However, I get the following output: (newlines added for clarity)
> >
> > laptop$ perl -e 'print hex '0xAf';'
> > 373
>
> so, you're double-use of single quotes here causes some fun shell
> processing. This is the same as:
>
> perl -e 'print hex 0xAf'
>
> (although let me re-do that with -E and say)
>
> $ perl -E 'say hex 0xAf'
> 373
>
> Well, as you say, that's not what you expect.
>
> But, perhaps there is an explanation. Lets try without hex.
>
> $ perl -E 'say 0xAf'
> 175
>
> interesting, but where's the hex?
>
> $ perl -E 'say hex 175'
> 373
>
> ahh, there it is.
>
> Just to get back on the original page though and avoid the shell
> confusion, lets try one last thing.
>
> $ perl -E 'say hex "0xAf"'
> 175
>
> And that work. Although I guess we can also
>
> $ perl -e 'print hex "0xAf"'
> 175
>
> if you'd like.
>
>
> > laptop$ perl -e 'print hex 'aF';'
> > 175
> >
> > I'm guessing there is a bug here but not sure if its software or
> > documentation.
> >
> > Thanks,
> >
> > Edgar
> >
>
> --
> andrew - http://afresh1.com
>
> Hey! It compiles! Ship it!
>
--
andrew - http://afresh1.com
Hey, I think I see a barn up ahead.
-- The American Astronaut
