hostuuid

   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 dot mailinglist -at- gmail dot 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 = '1.2';
  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 my $quiet;
  35 my $verify_uuid;
  36
  37
  38 GetOptions (
  39             'file|f=s'  => \$file,
  40             'help|h|?'  => \$print_help,
  41             'version|v' => \$print_version,
  42             'create|c'  => \$create_uuid,
  43             'quiet|q'   => \$quiet,
  44             'verify'    => \$verify_uuid,
  45            ) or print_help(255);
  46
  47 sub print_version() {
  48         unless ($quiet) {
  49                 print <<VERSION;
  50 $program: version $version
  51
  52 This program is released under GPLv3
  53 Written by Richard Hartmann for Debian and Grml
  54 VERSION
  55         }
  56         exit 0;
  57 }
  58
  59 sub print_help {
  60         my ($exit_code) = @_;
  61         unless ($quiet) {
  62                 print <<HELP;
  63 Help for $program:
  64
  65   -h, -?, --help : print this help
  66   -v, --version  : print version
  67   -f, --file     : file to read from/write to. Defaults to /etc/hostuuid
  68   -c, --create   : create & save UUID
  69   -q, --quiet    : Don't print anything
  70   --verify       : verify if there is a valid UUID in file
  71                    Does not print, only exits with zero/non-zero return code
  72 HELP
  73         }
  74         exit $exit_code;
  75 }
  76
  77 sub create_uuid() {
  78         my $uuid = find_hostuuid();
  79         if ($uuid) {
  80                 print STDERR "$program: Found UUID '$uuid' in '$file'. Aborting!\n" unless $quiet;
  81                 exit 101;
  82         } else {
  83                 open (F, ">", "$file") or do {
  84                         die "$program: Could not open file: '$file'\: $!\n" unless $quiet;
  85                         exit 2;
  86                 };
  87                 $uuid = create_UUID_as_string(UUID_V4);
  88                 print "$program\: Stored UUID '$uuid' in file '$file'\n" unless $quiet;
  89                 print F "$uuid\n";
  90                 close (F);
  91                 exit 0;
  92         }
  93 }
  94
  95 sub find_hostuuid() {
  96 #       if ($create_uuid) {return 0 unless -e $file;}
  97         return 0 unless ((-e $file && $create_uuid) || !$create_uuid);
  98         open (F, "<", "$file") or do {
  99                 die "$program: Could not open file: '$file'\: $!\n" unless $verify_uuid || $quiet;
 100                 exit 2;
 101         };
 102         while (<F>) {
 103                 if (/^([0-9a-z]{8}-([0-9a-z]{4}-){3}[0-9a-z]{12})/i) {
 104                         close (F);
 105                         return $1;
 106                 }
 107         }
 108 }
 109
 110 sub main() {
 111         unless (-t STDIN) {
 112                 if (<STDIN> =~ /^([0-9a-z]{8}-([0-9a-z]{4}-){3}[0-9a-z]{12})/i) {
 113                         print "$1 is a valid UUID\n" unless $verify_uuid || $quiet;
 114                         exit;
 115                 } else {
 116                         print "NOT a valid UUID\n" unless $verify_uuid || $quiet;
 117                         exit 105;
 118                 }
 119         }
 120         chomp $file;
 121         print_version() if $print_version;
 122         print_help(0)   if $print_help;
 123         create_uuid()   if $create_uuid;
 124
 125         my $uuid = find_hostuuid();
 126         if ($uuid) {
 127                 print "$uuid\n" unless $verify_uuid || $quiet;
 128                 exit 0;
 129         } else {
 130                 print STDERR "$program: Could not find UUID in '$file'\n" unless $verify_uuid || $quiet;
 131                 exit 100;
 132         }
 133 }
 134
 135 main();