Files owned in a filesystem

[grinder]

Ever found yourself staring at a deep filesystem and wondering which users own files in it? This little snippet will grovel through it and display a list of users, and the number of files that they own.

An alternative would be to count the bytes occupied by the files owned by a given person. In this case you would want to accumulate (stat $_)[7] instead. You might also then want to pretty print the bytes.

update: changed use of stat to lstat as per Merlyn's excellent suggestion. As it turns out, I was looking at a Samba share, and ordinary lusers can't create symlinks. Still, it's a good habit to get into.

#! /usr/bin/perl -w

use strict;
use File::Find;

my %owned;
find(
    sub { ++$owned{(lstat $_)[4]} unless $_ eq '.' or $_ eq '..' },
    shift || '.'
);

my %name;
$name{$_} = (getpwuid $_)[0] || "[uid $_]" foreach keys %owned;

print "$owned{$_}\t$name{$_}\n"
    foreach sort{ $name{$a} cmp $name{$b} }
    keys %owned;

[merlyn]

That should be lstat instead of stat, or else you'll count a symlinked file's size multiple times.

And actually, you should use (lstat)[12], which accounts properly for holey files and indirect blocks, to give you a number like du instead of like adding up a bunch of ls -l values.

-- Randal L. Schwartz, Perl hacker