#!/usr/bin/perl

# Last Update: 24 May 2010
# Designed by: Dusan U. Baljevic (dusan.baljevic@ieee.org)
# Coded by:    Dusan U. Baljevic (dusan.baljevic@ieee.org)
#
# Copyright 2010-2015 Dusan Baljevic
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
$ENV{'PATH'} = "/bin:/usr/sbin:/sbin:/usr/bin";

# Enforce strictness
#
if ( eval "require strict" ) {
    import strict;
    use strict;
}
else {
    print "WARN: Perl strict not found\n";
}

use Fcntl;

my $MYDEV = q{};
my $SEEK_SET = 0;
my $BUFSIZE = 512;
my $CKSUM_SEEK = 510;
my $CKSUM_BUFSIZE = 2;

sub Usage {
    print <<MYMSG
    USAGE: $CMD -d <diskdevice> [-h] 

    -d diskdev   Disk device to check label
                 (example, c7t600508B400102E8E0001500013FB0000d0)
    -h           Print this help message
MYMSG
      ;
    exit(0);
}

if ( eval "require Getopt::Std" ) {
   import Getopt::Std;
   getopts( 'd:h', \%opts );
   if ( $opts{h} ) {
      &Usage;
   }

   if ( ! "$opts{d}" ) {
      print "ERROR: Disk device not selected\n";
      &Usage;
      exit(1);
   }
   else {
      $MYDEV = "/dev/dsk/$opts{d}s0" || q{};
   }
}
else {
   warn "ERROR: Perl module Getopt::Std not found\n";
}

sysopen(FH, "$MYDEV", O_RDONLY) or die "ERROR: Cannot open device $MYDEV\n";
if ( sysseek(FH, 0, $SEEK_SET) ) {
   sysread(FH, $s, $BUFSIZE) or
   die "ERROR: Cannot read from device $MYDEV\n";
   close(FH);
}
else {
   print "ERROR: Cannot seek in device $MYDEV\n";
}

my $FORMAT = "Z*";
my $FIELDS = unpack($FORMAT, $s);

sysopen(CFH, "$MYDEV", O_RDONLY) or die "ERROR: Cannot open device $MYDEV\n";
if ( sysseek(CFH, 510, $SEEK_SET) ) {
   sysread(CFH, $c, $CKSUM_BUFSIZE) or
   die "ERROR: Cannot read from device $MYDEV\n";
   close(CFH);
}
else {
   print "ERROR: Cannot seek in device $MYDEV\n";
}

my $FORMAT = "Z*";
my $FIELDS = unpack($FORMAT, $s);
my $CFORMAT = "S";
my $CFIELDS = unpack($CFORMAT, $c);

print "Device = $MYDEV\n";
print "Current VENDOR STRING = $FIELDS\n";
print "Current checksum = $CFIELDS\n";

exit(0);