#! perl

# Store help text in variable
$syntax = "\nReadReg.pl,  Version 1.00 for Windows\n";
$syntax = $syntax."Read a value from the registry\n\n";
$syntax = $syntax."Usage:  READREG.PL  \"section\"  \"key\"\n\n";
$syntax = $syntax."Where:              \"section\"  is the section name, without brackets\n";
$syntax = $syntax."                    \"key\"      is the key whose value must be read\n\n";
$syntax = $syntax."Arguments should be enclosed in quotes\n\n";
$syntax = $syntax."Example:\nREADREG.PL \"HKEY_CURRENT_USER\\Environment\" \"path\"\n";
$syntax = $syntax."should return the user part of NT's PATH variable\n\n";
$syntax = $syntax."Written by Rob van der Woude\n";
$syntax = $syntax."http://www.robvanderwoude.com\n";

# Check number of command line arguments (2 required)
if ( !@ARGV[1] ) {
	die $syntax;
}

# Parse command line arguments
$section = @ARGV[0];
$key     = @ARGV[1];
if ( $section =~ m/^(HKEY_[^\\]+)\\(.+)$/i ) {
	$hive = uc( $1 );
	$tree = $2;
} else {
	die $syntax;
}

# Initialize the required module
use Win32API::Registry 0.21 qw( :ALL );

# Convert specified hive from string to constant
if ( $hive eq "HKEY_CLASSES_ROOT"   ) { $hkey = HKEY_CLASSES_ROOT;   }
if ( $hive eq "HKEY_CURRENT_CONFIG" ) { $hkey = HKEY_CURRENT_CONFIG; }
if ( $hive eq "HKEY_CURRENT_USER"   ) { $hkey = HKEY_CURRENT_USER;   }
if ( $hive eq "HKEY_LOCAL_MACHINE"  ) { $hkey = HKEY_LOCAL_MACHINE;  }
if ( $hive eq "HKEY_USERS"          ) { $hkey = HKEY_USERS;          }

# Read the value from the registry
RegOpenKeyEx( $hkey, $tree, 0, KEY_READ, $handle ) || die "Can't open $section: ".regLastError()."\n";
RegQueryValueEx( $handle, $key, [], $type, $regval, [] ) || die "Can't read $section\\$key: ".regLastError()."\n";
RegCloseKey( $handle ) ||  die "Can't close $section: ".regLastError()."\n";

# Display the result
print "\n[$section]\n$key=$regval\n";