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

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On 03/05/2017 10:25 AM, tomas@tuxteam.de wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On Sun, Mar 05, 2017 at 09:42:16AM -0600, Richard Owlett wrote:
>> I'm interested in "expr" and "bc".
>> The man pages lack reasonable examples.
>> The tutorial/HOWTO pages confuse the issue with fancy page layouts
>> and/or code samples showing how impressive the author can make the
>> script's output.
>[snip]
>
> If you need floating point numbers, bc (or dc) are your next stops.

Actually  dc is the solution.
I date from Byte's FORTH issue. Benn a fan ever since.
>
> Perhaps you start with a couple of small examples on what you want
> to achieve, post them here and we take them as riddles :-)

How about the whole app <grin>
You solved my problem with one line.
The so called tutorial on dc went to great length to make it look like 
paper coming out of a desk calculator that it obliterated any 
information. Discouraged me from even looking at the man page.

>
> Here's a little example with dc, [snip]
>
> If you wanted to catch the value instead of printing it right away,
> you would do
> fill=$(dc -e "5k $NOW $FULL / p")

That's the hint I needed <*GRIN*>

I needed to report the number of bytes downloaded for each portion of a 
project. My 1st pass is below. [I messed up something when I tried to 
divide by 1024 to get kb. Symptom was I somehow had a bad value on the 
stack]


mystring=$(echo $(grep "usb0" /proc/net/dev))
read -r -a myarray <<<$mystring
owl1=${myarray[1]}
echo $owl1

# insert process to be measured

mystring=$(echo $(grep "usb0" /proc/net/dev))
read -r -a myarray <<<$mystring
owl2=${myarray[1]}
echo $owl2
bytes=$(dc -e "1k  $owl2 $owl1 - p ")
echo "You have just downloaded " $bytes " bytes"

Someone on another group wanted me to use LibreOffice Calc ;/

Thanks

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Recomended tutoial(s) on doing arithmetic in Bash scripts Richard Owlett <rowlett@cloud85.net> - 2017-03-05 16:50 +0100
  Re: Recomended tutoial(s) on doing arithmetic in Bash scripts Reco <recoverym4n@gmail.com> - 2017-03-05 17:30 +0100
  Re: Recomended tutoial(s) on doing arithmetic in Bash scripts <tomas@tuxteam.de> - 2017-03-05 17:30 +0100
    Re: Recomended tutoial(s) on doing arithmetic in Bash scripts GiaThnYgeia <GiaThnYgeia@openmailbox.org> - 2017-03-05 19:20 +0100
      Re: Recomended tutoial(s) on doing arithmetic in Bash scripts <tomas@tuxteam.de> - 2017-03-05 21:40 +0100
      Re: Recomended tutoial(s) on doing arithmetic in Bash scripts Greg Wooledge <wooledg@eeg.ccf.org> - 2017-03-06 14:40 +0100
        Re: Recomended tutoial(s) on doing arithmetic in Bash scripts <tomas@tuxteam.de> - 2017-03-06 15:00 +0100
        Re: Recomended tutoial(s) on doing arithmetic in Bash scripts Jörg-Volker Peetz <jvpeetz@web.de> - 2017-03-06 16:00 +0100
          Re: Recomended tutoial(s) on doing arithmetic in Bash scripts <tomas@tuxteam.de> - 2017-03-06 16:40 +0100
    Re: Recomended tutoial(s) on doing arithmetic in Bash scripts Richard Owlett <rowlett@cloud85.net> - 2017-03-05 19:20 +0100
      Re: Recomended tutoial(s) on doing arithmetic in Bash scripts Richard Owlett <rowlett@cloud85.net> - 2017-03-05 19:50 +0100
      Re: Recomended tutoial(s) on doing arithmetic in Bash scripts <tomas@tuxteam.de> - 2017-03-05 21:30 +0100
        Re: Recomended tutoial(s) on doing arithmetic in Bash scripts Richard Owlett <rowlett@cloud85.net> - 2017-03-05 22:00 +0100
    Re: Recomended tutoial(s) on doing arithmetic in Bash scripts Jude DaShiell <jdashiel@panix.com> - 2017-03-05 23:20 +0100
      Re: Recomended tutoial(s) on doing arithmetic in Bash scripts Richard Owlett <rowlett@cloud85.net> - 2017-03-06 12:20 +0100
        Re: Recomended tutoial(s) on doing arithmetic in Bash scripts <tomas@tuxteam.de> - 2017-03-06 12:40 +0100
  Re: Recomended tutoial(s) on doing arithmetic in Bash scripts David Christensen <dpchrist@holgerdanske.com> - 2017-03-05 20:50 +0100
    Re: Recomended tutoial(s) on doing arithmetic in Bash scripts Richard Owlett <rowlett@cloud85.net> - 2017-03-05 21:50 +0100
      Re: Recomended tutoial(s) on doing arithmetic in Bash scripts David Christensen <dpchrist@holgerdanske.com> - 2017-03-06 04:40 +0100
    Re: Recomended tutoial(s) on doing arithmetic in Bash scripts <tomas@tuxteam.de> - 2017-03-05 22:30 +0100
  Re: Recomended tutoial(s) on doing arithmetic in Bash scripts Jude DaShiell <jdashiel@panix.com> - 2017-03-05 23:10 +0100

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