Comparing Directories
Saw this post fly past in the twitter stream today:"http://linuxshellaccount.blogspot.com/2008/03/perl-directory-permissions-difference.html".
It's a script by Mike Golvach to do something like a `diff -r`, but also
showing differences in permissions and ownership, rather than just content.
I've written a CPAN module to do stuff like this - File::DirCompare - so thought I'd check how straightforward this would be using File::DirCompare:
#!/usr/bin/perl
use strict;
use File::Basename;
use File::DirCompare;
use File::Compare qw(compare);
use File::stat;
die "Usage: " . basename($0) . " dir1 dir2\n" unless @ARGV == 2;
my ($dir1, $dir2) = @ARGV;
File::DirCompare->compare($dir1, $dir2, sub {
my ($a, $b) = @_;
if (! $b) {
printf "Only in %s: %s\n", dirname($a), basename($a);
} elsif (! $a) {
printf "Only in %s: %s\n", dirname($b), basename($b);
} else {
my $stata = stat $a;
my $statb = stat $b;
# Return unless different
return unless compare($a, $b) != 0 ||
$stata->mode != $statb->mode ||
$stata->uid != $statb->uid ||
$stata->gid != $statb->gid;
# Report
printf "%04o %s %s %s\t\t%04o %s %s %s\n",
$stata->mode & 07777, basename($a),
(getpwuid($stata->uid))[0], (getgrgid($stata->gid))[0],
$statb->mode & 07777, basename($b),
(getpwuid($statb->uid))[0], (getgrgid($statb->gid))[0];
}
}, { ignore_cmp => 1 });
So this reports all entries that are different in content or permissions or ownership e.g. given a tree like this (slightly modified from Mike's example):
$ ls -lR scripts1 scripts2 scripts1: total 28 -rw-r--r-- 1 gavin gavin 0 Mar 17 16:41 script1 -rw-r--r-- 1 gavin gavin 0 Mar 17 16:41 script1.bak -rw-r--r-- 1 gavin gavin 0 Mar 17 16:41 script2 -rw-r--r-- 1 gavin gavin 0 Mar 17 16:41 script2.bak -rw-r--r-- 1 gavin gavin 0 Mar 17 16:41 script3 -rw-r--r-- 1 gavin gavin 0 Mar 17 16:41 script3.bak -rw-r--r-- 1 gavin gavin 0 Mar 17 16:49 script4 scripts2: total 28 -rw-r--r-- 1 gavin users 0 Mar 17 16:41 script1 -rw-r--r-- 1 gavin users 0 Mar 17 16:41 script1.bak -rw-r--r-- 1 gavin gavin 0 Mar 17 16:41 script2 -rw-r--r-- 1 gavin gavin 0 Mar 17 16:41 script2.bak -rwxr-xr-x 1 gavin gavin 0 Mar 17 16:41 script3* -rwxr-xr-x 1 gavin gavin 0 Mar 17 16:41 script3.bak* -rw-r--r-- 1 gavin gavin 0 Mar 17 16:49 script5
it will give output like the following:
$ ./pdiff2 scripts1 scripts2 0644 script1 gavin gavin 0644 script1 gavin users 0644 script1.bak gavin gavin 0644 script1.bak gavin users 0644 script3 gavin gavin 0755 script3 gavin gavin 0644 script3.bak gavin gavin 0755 script3.bak gavin gavin Only in scripts1: script4 Only in scripts2: script5
This obviously has dependencies that Mike's version doesn't have, but it
comes out much shorter and clearer, I think. It also doesn't fork and parse
an external ls, so it should be more portable and less fragile. I should
probably be caching the getpwuid lookups too, but that would have made it
5 lines longer. ;-)