How to handle numeric variables in sh?

[Scott Milliken]

Here's a code snippet of a script I use often to number a bunch of pics
in a directory that I think shows how to do what you want to do:

$PICNUM=100
for FNAME in DSC*.JPG
do
NEWNAME=My_Pictures-$PICNUM.jpg
mv $FNAME $NEWNAME
PICNUM=$(($PICNUM+1))
done

This works in /bin/sh from my FreeBSD 4.11 system and also bash. If you
want to perform a mathematical operation on a shell variable, just
surround the expression with $(( expr )) and it'll work.

Hope that helps.

Scott Milliken

Alejandro Pulver wrote:

>Hello,
>
>Is there a way to handle numeric variables (addition, multiplication, etc.) in 'sh' (or throught an external command)?
>
>Thanks and Best Regards,
>Ale
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>freebsd-questions@freebsd.org mailing list
>[url]http://lists.freebsd.org/mailman/listinfo/freebsd-questions[/url]
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>
>!DSPAM:42176184998836675110134!
>
>
>

[Alejandro Pulver]

Hello,

Is there a way to handle numeric variables (addition, multiplication, etc.) in 'sh' (or throught an external command)?

Thanks and Best Regards,
Ale

[Eric Kjeldergaard]

On Sat, 19 Feb 2005 12:55:59 -0300, Alejandro Pulver
<alejandro@varnet.biz> wrote:

> Hello,
>
> Is there a way to handle numeric variables (addition, multiplication, etc.) in 'sh' (or throught an external command)?
>

`man bc`

--
If I write a signature, my emails will appear more personalised.

[Alejandro Pulver]

On Sat, 19 Feb 2005 10:07:51 -0600
Eric Kjeldergaard <kjelderg@gmail.com> wrote:

> On Sat, 19 Feb 2005 12:55:59 -0300, Alejandro Pulver
> <alejandro@varnet.biz> wrote:

> > Hello,
> >
> > Is there a way to handle numeric variables (addition, multiplication, etc.) in 'sh' (or throught an external command)?
> >

>
> `man bc`
>
> --
> If I write a signature, my emails will appear more personalised.
> _______________________________________________
> [email]freebsd-questions@freebsd.org[/email] mailing list
> [url]http://lists.freebsd.org/mailman/listinfo/freebsd-questions[/url]
> To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"

Thank You.

Best Regards,
Ale

[Jon Drews]

Ale:


On Sat, 19 Feb 2005 12:55:59 -0300, Alejandro Pulver
<alejandro@varnet.biz> wrote:

> Hello,
>
> Is there a way to handle numeric variables (addition, multiplication, etc.) in 'sh' (or throught an external command)?

Here is a good short "HowTo" on calling bc:
-----------------------------------------------------------------

>> Shell Tip: Calculating with large numbers using "bc"

-----------------------------------------------------------------
[url]http://www.shelldorado.com/newsletter/issues/2002-3-Aug.html[/url]

Shelldorado is a great reference site:

[url]http://www.shelldorado.com/[/url]

[Alejandro Pulver]

On Sat, 19 Feb 2005 10:24:04 -0500
Scott Milliken <scott.milliken@e-comsultant.net> wrote:

> Here's a code snippet of a script I use often to number a bunch of pics
> in a directory that I think shows how to do what you want to do:
>
> $PICNUM=100
> for FNAME in DSC*.JPG
> do
> NEWNAME=My_Pictures-$PICNUM.jpg
> mv $FNAME $NEWNAME
> PICNUM=$(($PICNUM+1))
> done
>
> This works in /bin/sh from my FreeBSD 4.11 system and also bash. If you
> want to perform a mathematical operation on a shell variable, just
> surround the expression with $(( expr )) and it'll work.
>
> Hope that helps.
>
> Scott Milliken
>

Thank You.

Y saw the use of '$(( expr ))' some time ago in 'Advanced Bash Scripting Guide', but I thought it was only for 'bash'.

I am using FreeBSD 5.3 and it also works in '/bin/sh'.

Best Regards,
Ale

[Alejandro Pulver]

On Sat, 19 Feb 2005 09:33:11 -0700
Jon Drews <jon.drews@gmail.com> wrote:

> Ale:
>
>
> On Sat, 19 Feb 2005 12:55:59 -0300, Alejandro Pulver
> <alejandro@varnet.biz> wrote:

> > Hello,
> >
> > Is there a way to handle numeric variables (addition, multiplication, etc.) in 'sh' (or throught an external command)?

>
> Here is a good short "HowTo" on calling bc:
> -----------------------------------------------------------------

> >> Shell Tip: Calculating with large numbers using "bc"

> -----------------------------------------------------------------
> [url]http://www.shelldorado.com/newsletter/issues/2002-3-Aug.html[/url]
>
> Shelldorado is a great reference site:
>
> [url]http://www.shelldorado.com/[/url]
> _______________________________________________
> [email]freebsd-questions@freebsd.org[/email] mailing list
> [url]http://lists.freebsd.org/mailman/listinfo/freebsd-questions[/url]
> To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"

Interesting site.

Thank You.

Best Regards,
Ale

[JarJarBings]

hi,

have a look at "man expr"

regards

Alejandro Pulver wrote:

> Hello,
>
> Is there a way to handle numeric variables (addition, multiplication, etc.) in 'sh' (or throught an external command)?
>
> Thanks and Best Regards,
> Ale
> _______________________________________________
> [email]freebsd-questions@freebsd.org[/email] mailing list
> [url]http://lists.freebsd.org/mailman/listinfo/freebsd-questions[/url]
> To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"
>

[Alejandro Pulver]

On Sat, 19 Feb 2005 20:16:23 +0100
JarJarBings <jarjarbings@aon.at> wrote:

> hi,
>
> have a look at "man expr"
>
> regards
>
> Alejandro Pulver wrote:

> > Hello,
> >
> > Is there a way to handle numeric variables (addition, multiplication, etc.) in 'sh' (or throught an external command)?
> >
> > Thanks and Best Regards,
> > Ale

Thank You.

Bests Regards,
Ale