# linuxGetServerFreeSpace.pl
#
# by Dean Giles 
# Version 1.0 
# October 15, 2008
#
# This Perl script lists free disk space on the server.
# 
# This script has been designed to be run on Linux. 
# The API set can be downloaded from  http://developer.novell.com/wiki/index.php/Virtual_File_Services_for_NetWare. 
# 
# The Perl script requires the name of an NSS pool, a storage pool, and the name of the new snapshot
# as input.  It requires that NSS be installed and an NSS pool be present.
#

{
	# User help function
	if ($ARGV[0] eq "/?" || $ARGV[0] eq "-?") 
	{
		print "USAGE: perl linuxGetServerFreeSpace.pl \n";
		
		print "Example: perl linuxGetServerFreeSpace.pl \n";
		print "this will list the free space on server disks. \n";
		exit;
	}

	# Global Variables
	$file = "+</_admin/Manage_NSS/manage.cmd"; # This is the MSS management file we are accessing.
	$reply;	   # Variable used to read from file.
	$command; # This is the NSS xml command that will be the NSS request to the file.
	$error;  # Variable used to manage errors.
	
	# Open the file and check that it exists.
	open(NSSFILE, $file) 
  		or die "Error opening NSS management file ($!) on server";
	print "file is now open \n";
	$command = "<virtualIO><datastream name=\"command\"/></virtualIO>".
			"<nssRequest>".
			"<server>".
    		"<getServerFreeSpace/>".
     		"</server>".
     		"</nssRequest>"; 

	# This is the command for initializing the virtual file for sending a command.
	print "File Name: $file \n";
	print "Request Sent: $command \n"; 

	
	if (!syswrite(NSSFILE, $command, length($command))) #Initialize the nss management file and write a command.
	{
		
		seek NSSFILE, 0, 0;	  # Make sure to start at the beginning of the file.
		sysread (NSSFILE, $error, 10000);  #Read the error message.
		
		print "Error writing initialization to management file. \n";
		print "$error  \n\n";	 #Print the error message to the screen.
		close (NSSFILE);
	}
	else
	{
		seek NSSFILE, 0, 0;	  # Make sure to start at the beginning of the file.
	
		sysread (NSSFILE, $reply, 10000);  #Read the reply.
	
		print "$reply  \n\n";	 #Print the reply to the screen.
		
		close (NSSFILE);
  	}
}