Linux - Sum total of files in different directories - linux

Question

How do I calculate the sum total size of multiple files located in different directories?
I have a text file containing the full path and name of the files.
I figure a simple script using while read line and du -h might do the trick...
Example of text file (new2.txt) containing list of files to sum:
/mount/st4000/media/A/amediafile.ext
/mount/st4000/media/B/amediafile.ext
/mount/st4000/media/C/amediafile.ext
/mount/st4000/media/D/amediafile.ext
/mount/st4000/media/E/amediafile.ext
/mount/st4000/media/F/amediafile.ext
/mount/st4000/media/G/amediafile.ext
/mount/st4000/media/H/amediafile.ext
/mount/st4000/media/I/amediafile.ext
/mount/st4000/media/J/amediafile.ext
/mount/st4000/media/K/amediafile.ext
Note: the folder structure is not necessarily consecutive as in A..K
Based on the suggestion from AndreaT, adapting it slightly, I tried
while read mediafile;do du -b "$mediafile"|cut -f -1>>subtotals.txt;done<new2.txt
subtotals.txt looks like
733402685
944869798
730564608
213768
13332480
366983168
6122559750
539944960
735039488
1755005744
733478912
To add all the subtotals
sum=0; while read num; do ((sum += num)); done < subtotals.txt; echo $sum

Answer 1

Assuming that file input is like this
/home/administrator/filesum/cliprdr.c
/home/administrator/filesum/cliprdr.h
/home/administrator/filesum/event.c
/home/administrator/filesum/event.h
/home/administrator/filesum/main.c
/home/administrator/filesum/main.h
/home/administrator/filesum/utils.c
/home/administrator/filesum/utils.h
and the result of command ls -l is
-rw-r--r-- 1 administrator administrator 13452 Oct 4 17:56 cliprdr.c
-rw-r--r-- 1 administrator administrator 1240 Oct 4 17:56 cliprdr.h
-rw-r--r-- 1 administrator administrator 8141 Oct 4 17:56 event.c
-rw-r--r-- 1 administrator administrator 2164 Oct 4 17:56 event.h
-rw-r--r-- 1 administrator administrator 32403 Oct 4 17:56 main.c
-rw-r--r-- 1 administrator administrator 1074 Oct 4 17:56 main.h
-rw-r--r-- 1 administrator administrator 5452 Oct 4 17:56 utils.c
-rw-r--r-- 1 administrator administrator 1017 Oct 4 17:56 utils.h
the simplest command to run is:
cat filelist.txt | du -cb | tail -1 | cut -f -1
with following output (in bytes)
69370
Keep in mind that du prints actual disk usage rounded up to a multiple of (usually) 4kb instead of logical file size.
For small files this approximation may not be acceptable.

Answer 2

To sum one directory, you will have to do a while, and export the result to the parent shell.
I used an echo an the subsequent eval :
eval ' let sum=0$(
ls -l | tail -n +2 |\
while read perms link user uid size date day hour name ; do
echo -n "+$size" ;
done
)'
It produces a line, directly evaluated, which looks like
let sum=0+205+1201+1201+1530+128+99
You just have to reproduce twice this command on both folders.

Answer 3

The du command doesn't have a -b option on the unix systems I have available. And there are other ways to get file size.
Assuming you like the idea of a while loop in bash, the following might work:
#!/bin/bash
case "$(uname -s)" in
Linux) stat_opt=(-c '%s') ;;
*BSD|Darwin) stat_opt=(-f '%z') ;;
*) printf 'ERROR: I don'\''t know how to run on %s\n' "$(uname -s)" ;;
esac
declare -i total=0
declare -i count=0
declare filename
while read filename; do
[[ -f "$filename" ]] || continue
(( total+=$(stat "${stat_opt[#]}" "$filename") ))
(( count++ ))
done
printf 'Total: %d bytes in %d files.\n' "$total" "$count"
This would take your list of files as stdin. You can run it in BSD unix or in Linux -- the options to the stat command (which is not internal to bash) are the bit that are platform specific.