Sum of filesize of a list of files

Question

I have a text-file that contains a list of filenames (one filename per line).

Now I would like to calculate the size of all these files. I think I will have to do a ls -la on every line of the file and then accumulate the filesize.

I think that awk will be part of the solution, but thats just guess.

Answer 1

You need just last line of du -c output

du -ch $(<list) | tail -1

Answer 2

With GNU stat:

stat -c %s -- $(<list) | paste -d+ -s - | bc

• stat displays information about the file
  • -c specifies the format, %s gives the filesize in bytes
• paste -d+ -s concats the output together line by line with a + as delimiter
• bc piped to bc, it will be calculated together.

Add a -L option to stat, if for symlinks, you'd rather count the size of the file that the symlink eventually resolves to.

That assumes a shell like ksh, bash or zsh with the $(<file) operator to invoke split+glob on the content of a file.

Here list is expected to be a space, tab or newline (assuming the default value of $IFS) delimited list of file patterns (as in *.txt /bin/*). For a list of file paths, one per line, you'd need to disable globbing and limit $IFS to newline only, or with GNU xargs:

xargs -rd '\n' -a list stat -c %s -- | paste -sd+ - | bc

Answer 3

I would use the -s file test and perl:

-s File has nonzero size (returns size in bytes).

Something like this:

#!/usr/bin/env perl;
use strict;
use warnings;

my $sum = 0;
while ( my $filename = <> ) {
    chomp ( $filename );
    $sum += -s $filename;
}

print "Sum is $sum bytes\n";

(reads filenames either from STDIN or from a file specified on command line, e.g. myscript.pl file_list.txt)

You could "one liner" this:

perl -nle '$sum += -s $_; END { print $sum }'

(and either pipe in a 'file name list' or specify a file argument after it as before)

Answer 4

Another alternative, using ordinary shell commands. Even handles the filename-with-spaces case. Assumes that list of file names is in a file named fnames.

tr '\n' '\0' < fnames | xargs -0 cat | wc -c

wc is oddly useful in counting situations. Keep it in mind.

Answer 5

I also came up with a solution:

cat files.txt | while read f; do ls -la $f; done | awk '{s+=$5;} END {print s;}'

Answer 6

For filenames with space in my list, I used this (inspired by @Costas's answer):

SAVEIFS=$IFS
IFS=$(echo -en "\n\b")
du -ch $(<list) |tail -1
IFS=$SAVEIFS