UNIX for Dummies Questions & Answers

hi,

i currently have a file with columns similar to this

customer name owed
CID123 John 300
CID342 harry 500

at present i use use awk to find the amount owed by the customer using the customer ID (CID).

if the customer spends more money how would i go about using sed/awk etc to modify the amount they owe? (all the arithmetic is already working, i just need to know how to append the new value to the file under the owed column for the correct customer)

thanks for any pointers
skinnygav

This might be a lame answer, but here it goes:
You can save each column into arrays

Code:

array1
Customer
CID****
CID****
.......
....

For corresponding CID*** of array1[i] u'll easily get array3[i] which simplifies your arithmatic part. You can make the updates or changes in owed i.e array3 and then rewrite the whole file using these updated arrays.

There might be a much simpler solution i.e. updating only the ones that have changed, this is what i would have done

I suppose data.txt is the filename:

Code:

cid="CID342"
newVal="007"

set -A arrVals `grep "${cid}" data.txt | awk '{print $1" "$2" "$3}'`
sed "s/${cid} .*/${arrVals[0]} ${arrVals[1]} ${newVal}/g" data.txt > tmp.tmp
mv tmp.tmp data.txt

I hope it helps.

Regards,
HKansal