Very Computer

I have something that looks like this:

total=0
grep -E "pattern" file | while read line; do
        size=$(echo $line | cut -f3 -d ' ')
    total=$(($total + $size))
done
echo $total

Needless to say, I get a total of 0 in the end, because the whole while
loop executes in a subshell.
Is there any way I can parse this file and add up the 3rd field of the
select lines, and get a total that I can use in the rest of the script?

Thanks,
Moshe

--

Sure, you could do something like this:

total=0
grep -E "pattern" file | while read line; do
        size=$(echo $line | cut -f3 -d ' ')
    total=$(($total + $size))
echo $total > mytotal
done
total=`cat mytotal`
rm mytotal
echo $total

but I suspect it's easier to do the whole thing like this:

total=0
total=`grep -E "pattern" file |
awk -v sum=$total '{sum+=$3} END {print sum}'`
echo $total

or the simpler (which assumes the prior total is zero):

total=`grep -E "pattern" file | awk '{sum+=$3} END {print sum}'`
echo $total

Chuck Demas
Needham, Mass.

--
  Eat Healthy    |   _ _   | Nothing would be done at all,

  Die Anyway     |    v    | That no one could find fault with it.

awk ' $0 ~ /pattern/ { tot += $3 } END { print tot } '
file

or something close. "man awk" for more details.