Re: convert hex to decimal?

From: Michael Heiming (michael+USENET_at_www.heiming.de)
Date: 02/08/04

  • Next message: A. Alper ATICI: "Re: convert hex to decimal?" 
    Date: Sun, 8 Feb 2004 00:57:06 +0100

    Chris F.A. Johnson <c.fa.johnson@rogers.com> wrote:
    > On Sat, 07 Feb 2004 at 21:23 GMT, William Park wrote:
    > > Chris F.A. Johnson <c.fa.johnson@rogers.com> wrote:
    > >> On Sat, 07 Feb 2004 at 20:45 GMT, joe@invalid.address wrote:
    > >> > William Park <opengeometry@yahoo.ca> writes:
    > >> >> How about
    > >> >> printf "%d.%d.%d.%d\n" `echo ffffff80 | sed 's/../ 0x&/g'`
    > >> >
    > >> > That's better than mine alright.
    > >>
    > >> But MANY times slower.
    > >
    > > Not when you count time for typing, debugging, etc.

    > If it's a one-time execution, you may be right, but if it's in a
    > script that is run many times (or if it's executed several times
    > in a script), then it is definitely slower. (The difference will
    > be much more pronounced in bash than in ksh.)

    [..]

    > The biggest difference is probably the time taken to think of the
    > method, and that will vary from person to person. I'd come up with

    Ack, came up with using bc quite fast.

    > a solution like Joe's much faster than one using sed. FWIW, here's
    > mine:

    > hex=ffffff80
    > h1=${hex%????}
    > h2=${hex#????}
    > printf "%d.%d.%d.%d\n" 0x${h1%??} 0x${h1#??} 0x${h2%??} 0x${h2#??}

    Timed your solution, William's and mine:

    After a few hundred runs it finishes:

    real 0m0.007s (CFAJ)

    real 0m0.012s (William P.)

    real 0m0.012s (Michael H.)

    >From a programmer view, yours should be the cleanest/fastest. But
    from my point, the fastest typing is what counts.

    ;)

    Greetings 

    -- 
Michael Heiming - RHCE
Remove +SIGNS and www. if you expect an answer, sorry for 
inconvenience, but I get tons of SPAM
  • Next message: A. Alper ATICI: "Re: convert hex to decimal?"

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