bc question

Shell Programming and Scripting
1

i'm trying to parse a file with lines like the below where i need to get a diff on the 169-182 so that the result is 13 for instance. I was looking into using bc but am not that familiar with embedding it in a script.

john8:9. 169-182

any ideas are appreciated!

2 
echo "john8:9. 169-182" | cut -d" " -f2 | awk -F"-" '{print $2-$1}'
13
3 
echo "john8:9. 169-182" | awk '{print "(" $2 ")*-1"}' | bc
4

thanks joeyg and pludi. I understand your commands now so thanks. i'm trying to send a filename so would it be the following?

cut -d" " -f2 filename | awk -F"-" '{print $2-$1}'

5

In that example, your filename is an input to the rest of the command.

6

ok, i'm doing something more like this

awk -F" -+" '{print $3 " " $7-$6+1}' L220090213RetransRequests.log

the ibm site is goog for awk teaching:

Common threads: Awk by example, Part 1

thanks again!