Need a quick way to add up file sizes in Linux

Factual Questions
1

Say I have a bunch of files in a Linux directory called foo.1, foo.2, and so forth, and I want to know the total size of all the files. If they were the only files in the directory, I could use “du -ab --max-depth=1” and then ignore everything but the last line. But they’re not the only files in the directory, and the other files don’t match any fixed pattern that I could use with the “-exclude” option to du.

Currently, I’m using the following hideous bit of hackery:


ls -l foo.* | awk '{print $5}' | perl -ple '$_=$t+=$_' | tail -n 1

But there’s got to be a better way than that. Anyone know what it is?

(There’s probably some perfectly obvious Unix command that does this that I just don’t know about…)

2

Awk can do the math for you.


ls -l foo.* | awk '{print sum+=$5}' | tail -n 1
3

See? I knew there was some bit of Unix arcana I didn’t know that would help. Thanks!

(In case it’s not blindingly obvious, someone once showed me how awk could be used to extract a given column from text output and I haven’t used it for anything else since.)

4

How about doing it with only one pipe?


ls -l foo.* | awk '{tot+=$5} END {print tot}'
5

gotcha all beat

cat foo.* | wc -c

Ok, that’s not a great idea if your files have any size to them.

6

du -c foo.*

will give you a total at the end, but will also show you the size of all the files that match the expression. You could do

du -c foo.* | tail -1

if you only want the total line. And of course it will say “total” after the total size, so you’d have to strip that off if you cared.

7

I’d do it all in Perl, myself:



perl -e 'for (glob "foo.*") {$sum += -s} print "$sum
";'

I think that’s clearer than most of the shell alternatives, and it can be trivially migrated to its own file for use as a standalone program.

(Yes, that’s tested code. I love Linux. :D)