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

Pure bash

total=0; for i in $(cat files.txt | xargs ls -l | cut -c 23-30); do 
total=$(( $total + $i )); done; echo $total

Answer 2

If you have R, you can use:

> ... | Rscript -e 'print(sum(scan("stdin")));'
Read 4 items
[1] 2232320

---

Since I'm comfortable with R, I actually have several aliases for things like this so I can use them in bash without having to remember this syntax. For instance:

alias Rsum=$'Rscript -e \'print(sum(scan("stdin")));\''

which let's me do

> ... | Rsum
Read 4 items
[1] 2232320

Inspiration: Is there a way to get the min, max, median, and average of a list of numbers in a single command?

Answer 3

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...

Answer 4

In my opinion, the simplest solution to this is "expr" unix command:

s=0; 
for i in `cat files.txt | xargs ls -l | cut -c 23-30`
do
   s=`expr $s + $i`
done
echo $s

Answer 5

python3 -c"import os; print(sum(os.path.getsize(f) for f in open('files.txt').read().split()))"

Or if you just want to sum the numbers, pipe into:

python3 -c"import sys; print(sum(int(x) for x in sys.stdin))"

Answer 6

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