hostuuid.pl

   1 #!/usr/bin/perl
   2
   3 #This program is free software: you can redistribute it and/or modify
   4 #it under the terms of the GNU General Public License as published by
   5 #the Free Software Foundation, either version 3 of the License, or
   6 #(at your option) any later version.
   7 #
   8 #This program is distributed in the hope that it will be useful,
   9 #but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 #MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 #GNU General Public License for more details.
  12 #
  13 #You should have received a copy of the GNU General Public License
  14 #along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 # Written by Richard Hartmann in 2009, feel free to email
  17 # richih.mailinglist@gmail.com with questions.
  18
  19
  20 use strict;
  21 use warnings;
  22
  23 use UUID::Tiny;
  24 use Getopt::Long qw(:config no_ignore_case bundling);
  25 use File::Basename;
  26
  27 my $version = '1.0';
  28 my $program = basename($0);
  29
  30 my $file = '/etc/hostuuid';
  31 my $print_version;
  32 my $print_help;
  33 my $create_uuid = 0;
  34
  35 GetOptions (
  36             'file|f=s'  => \$file,
  37             'help|h|?'  => \$print_help,
  38             'version|v' => \$print_version,
  39             'create|c'  => \$create_uuid,
  40            );
  41
  42 sub print_version() {
  43         print <<VERSION;
  44 $program: version $version
  45
  46 This program is released under GPLv3
  47 Written by Richard Hartmann for Debian and Grml
  48 VERSION
  49         exit 0;
  50 }
  51
  52 sub print_help() {
  53         print <<HELP;
  54 Help for $program:
  55
  56   -h, -?, --help : print this help
  57   -v, --version  : print version
  58   -f, --file     : file to read from/write to. Defaults to /etc/hostuuid
  59   -c, --create   : create & save UUID
  60 HELP
  61         exit 0;
  62 }
  63
  64 sub create_uuid() {
  65         my $uuid = find_hostuuid();
  66         if ($uuid) {
  67                 print STDERR "$program: Found UUID '$uuid' in '$file'. Aborting!\n";
  68                 exit 101;
  69         } else {
  70                 open (F, ">", "$file") or die "$program: Could not open file: '$file'\: $!\n";
  71                 $uuid = create_UUID_as_string(UUID_V4);
  72                 print "$program\: Stored UUID '$uuid' in file '$file'\n";
  73                 print F "$uuid\n";
  74                 close (F);
  75                 exit 0;
  76         }
  77 }
  78
  79 sub find_hostuuid() {
  80 #       if ($create_uuid) {return 0 unless -e $file;}
  81         return 0 unless ((-e $file && $create_uuid) || !$create_uuid);
  82         open (F, "<", "$file") or die "$program: Could not open file: '$file'\: $!\n";
  83         while (<F>) {
  84                 if (/([0-9a-z]{8}-([0-9a-z]{4}-){3}[0-9a-z]{12})/i) {
  85                         close (F);
  86                         return $1;
  87                 }
  88         }
  89 }
  90
  91 sub main() {
  92         print "\n\nIf anyone knows how to die() when there is no value for -f, tell me!\n\n";
  93         chomp $file;
  94         print_version() if $print_version;
  95         print_help()    if $print_help;
  96         create_uuid()   if $create_uuid;
  97
  98         my $uuid = find_hostuuid();
  99         if ($uuid) {
 100                 print "$uuid\n";
 101                 exit 0;
 102         } else {
 103                 print STDERR "$program: Could not find UUID in '$file'\n";
 104                 exit 100;
 105         }
 106 }
 107
 108 main();