Add up a column of numbers at the Unix shell

Question

Given a list of files in files.txt, I can get a list of their sizes like this:

cat files.txt | xargs ls -l | cut -c 23-30

which pr

Answer 1

I like to use....

echo "
1
2
3 " | sed -e 's,$, + p,g' | dc 

they will show the sum of each line...

applying over this situation:

ls -ld $(< file.txt) | awk '{print $5}' | sed -e 's,$, + p,g' | dc 

Total is the last value...