awk - arithemetic functions with external variables

Shell Programming and Scripting
1

I'm trying to get awk to do arithmetic functions with external variables and I'm getting an error that I cannot figure out how to fix.

Insight would be appreciated

        money=$1
        rate1=$(awk -F"\t " '/'$converting'/{print $3}' convert.table)
        rate2=$(awk -F"\t" '/'$converted'/{print $3}' convert.table)
        awk -F"\t" '{printf '$rate2'/'$rate1'*'$money'}'

OUTPUT

awk: cmd. line:1: {printf 3.3513
awk: cmd. line:1: ^ unexpected newline or end of string

2

You cannot pass external variables into awk in the manner that you are attempting to use.

Try:

awk -F"\t" -v rate1=$rate1 -v rate2=$rate2 -v money=$money '{print rate2/rate1*money}'
3

I'm not at a UNIX machine now, but this should work:

        money=$1
        rate1=$(awk -F"\t " '/'$converting'/{print $3}' convert.table)
        rate2=$(awk -F"\t" '/'$converted'/{print $3}' convert.table)
        awk -F"\t" '{printf r2/r1*m}' r2=$rate2 r1=$rate1 m=$money