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

cat will not work if there are spaces in filenames. here is a perl one-liner instead.

perl -nle 'chomp; $x+=(stat($_))[7]; END{print $x}' files.txt