http://www.perlmonks.org?node_id=202898
Description:

rch.pl recurses a filesystem, starting at a user-specified directory, ch(mod|own|grp)ing everything in it's path.   Additional arguments are user to chown to, and separate octal perms for directories and for files.

Use with caution.   Must be run as root, just like *nix ch(own|grp).   You can hose your *nix system with this if you're not careful, just like with *nix ch(mod|own|grp).   As a precautionary measure, it will cowardly refuse to recurse from '/'.

Scratches an itch that arose when I moved all my data files from shares on a Win2k box to Debian host w/Samba.   As always, comments and suggestions are welcome.

Update: Chagrined thanks to bluto and merlyn for pointing out *nix chmod and chown syntax I wasn't aware of.   I'm still glad I wrote this'un, as it scratches my one itch better, and also for having learned a thing or two about File::Find, and Pod::Usage as root.   This is (Perl|*nix), so there's more than one way of doing this.   8^)

#!/usr/bin/perl -w

# rch.pl
# pod at tail

use strict;            # avoid D'oh! bugs
use User::pwent;       # map username to uid/gid
use File::Find;        # recurse the filesystem
$|++;                  # STDOUT hot

my $user     = shift;
my $baseDir  = shift;
my $modeFile = oct(shift);
my $modeDir  = oct(shift);

eXit() unless $< == 0;
eXit() unless $baseDir && $user && $modeFile && $modeDir;
eXit() unless grep /^[0-7]{1,4}$/, $modeFile, $modeDir;
eXit() if $baseDir eq '/';

my $pw = getpwnam($user);
eXit() unless($pw);
my $uid = $pw->uid;
my $gid = $pw->gid;

sub chMOG {
  chmod($modeFile, $_) if(-f $_);
  chmod($modeDir, $_)  if(-d $_);
  chown($uid, $gid, $_);
}

sub eXit {
  print "\nD'oh!  Invalid/missing input or you're not root.";
  print "\nperldoc rch.pl and try again.";
  print "\nBut you can't perldoc as root.";
  print "\nSo there.\n\n";
  exit;
}

find(\&chMOG, "$baseDir");


=head1 TITLE

 rch.pl - Recursively ch(mod|own|grp) files and directories

=head1 SUMMARY

 rch.pl user base_dir file_mode dir_mode

 Base dir can be either relative or absolute, but *can't* be '/'.
 File and dir modes must be in octal, with or without the leading zero
+.

 0664 = user+group:rw    other:r
 0775 = user+group:rwx   other:rx

 0644 = user:rw    group+other:r
 0755 = user:rwx   group+other:rx

=head1 USAGE

 rch.pl user base_dir file_mode dir_mode

=head1 COMMENTS


=head1 TESTED

 User::pwent (no VERSION)
 File::Path  (no VERSION)
 Perl        5.006.01
 Debian      3.0

=head1 UPDATES

 2002-10-05   09:15 CST
 Tone down caution, as is no more hazardous than *nix ch(mod|own|grp)
 Post to PerlMonks
 Subify abort messages+exit
 Try and rule out Pod::Usage
   "Superuser must not run perldoc without security audit and taint ch
+ecks"
 Sanity-check user-supplied file/dir modes
 Automate name-to-uid/gid mapping
 Accept octal file & dir modes as commandline args

 2002-09-18   14:50 CST
 Fix borken POD

 2002-08-04   12:15 CST
 Initial working code

=head1 TODO

 Sanity-check user-provided username

=head1 CREDITS

 Props to davis, jwest, rob_au, tye, demerphq and zigdon for tips in t
+he CB.
 And to some guy named vroom.

=head1 AUTHOR

 ybiC

=cut