Perform addition using a while or until loop??

[Monunix]

Hi,
I'm need to write a shell script that performs addition as much as the user requires using a while or an until loop but can only find "basic" addition script. Please help if you can.
Thanks/

 

[dickiebird]

What is 'basic' ?
((vara=$vara+99))
or
((vara=$vara + $varb)) ??

Post what you have and what you want in more detail.

Dickie Bird (-)))

 

[Monunix]

Hi Dickiebird,
I work as an instructor for a telecom company and deliver a system administration course for a node based on a ufs and so this request came from one of my students. I don't do any scripting as part of the course - (it's mostly troubleshooting, backups & dumps )but have found a few basic calculating scripts in some unix text books but nothing with while or until...would I be right in assuming it's not a simple thing to do??
Thanks for your response anyway.

 

[dickiebird]

Nope - easy example :-

while :
do
print "Enter a number to add to total or 0 to quit \c"
read num
((total=$total + num))
if [ $num -eq 0 ]
then
exit
fi
print "\nRunning total is $total \n\n"
done

Dickie Bird (-)))

 

[Monunix]

Thanks a lot.
Monica

 

[bi]

And here's another example if you have a bunch of files with numbers in them you want to add up and put the total in another file:

for filename in *.num
do
typeset -i i
i=0
while read -r j
do
i=i+j
done < ${filename}
echo $i > ${filename}.total
done

 

[SamBones]

In the Korn shell, you can use the very C like...

    (( TOTAL += NUM ))

...for adding the number to the total. Note, you don't use the dollar sign. It's actually just using the variable name.

Hope this helps.