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Old 2nd February 2013
J65nko J65nko is offline
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Join Date: May 2008
Location: Budel - the Netherlands
Posts: 4,131
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To use a simpler version, called kal that only does a single calculation without formatting the numbers, you can use the following in your .profile:
Code:
# $OpenBSD: dot.profile,v 1.4 2005/02/16 06:56:57 matthieu Exp $
#
# sh/ksh initialization

PATH=$HOME/bin:/bin:/sbin:/usr/bin:/usr/sbin:/usr/X11R6/bin:/usr/local/bin:/usr/local/sbin:/usr/games:.
export PATH HOME TERM
export PAGER=/usr/bin/less
export PS1="[\u@\h]\w: "

kal(){ echo "scale=4 ; $@" | bc ;}
One caveat: the multiplication operator '*' is also used one of the the shell file name wildcard/patterns. To prevent problems you have to either escape the '*' with a blackslash or use single quotes to delimit your arithmetic expression.

To stimulate the neurons in your gr[ae]y matter, an uncommented illustration of something you can run into:
Code:
$ ls -l 2013*

-rw-r--r--  1 j65nko j65nko  0 Feb  2 19:35 2013-02-01_data24
-rw-r--r--  1 j65nko j65nko  0 Feb  2 19:40 20134343

$  kal 2013*3
20134343

$ kal 2013\*3
6039

$  kal 2013*4 
bc: stdin:1: syntax error: _data24 unexpected

$ kal '2013*4'
8052
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