ioiioi has asked for the wisdom of the Perl Monks concerning the following question:

I would like to monitor a file located on remote host(win2k).so I want to use a perl script to get this file's info, and run it as a task.My computer runs win2k, either with the remote host. actually, I am very interesting with perl co-operate with WMI, this is sample script. but unfortunately. I really unfamiliar with WMI. 
use strict;
use Win32::OLE;

my $output_delimeter = " ";
my $argCount = scalar(@ARGV);

my $Win32_Class = "Win32_Processor";

#Display help if
if ($argCount == 0) {

my @script_name = split m!\\!, $0;

print <<"END";
Display information in the $Win32_Class class of a computer using Wind
+ows Management Instrumentation (WMI).

(The user account running this script must have access to the WMI repo
+sitory of the target host.)

$script_name[((scalar(@script_name)) - 1)] computer action rvalue

Parameters:

   computer    - the name of the computer to query
   action      - index, query, get or browse
                 Note: browse will return all of the properties in thi
+s class.
   rvalue      - the value or values you want back
                 (LoadPercentage)
   kvalue      - the number of processors you want to query
                 (2)

If a comma separated list of rvalues is passed to this script, the res
+ults will be returned space delimited.

Consult the Microsoft WMI documentation for more information about Win
+dows Management Instrumentation.
http://msdn.microsoft.com/library/en-us/wmisdk/wmi/wmi_start_page.asp

Example:

   $script_name[((scalar(@script_name)) - 1)] localhost index
   $script_name[((scalar(@script_name)) - 1)] localhost browse
   $script_name[((scalar(@script_name)) - 1)] localhost get LoadPercen
+tage 1
END

    exit;
}


#Parse through the command-line arguments and display the WMI informat
+ion.

 WMIMain(@ARGV);


sub    WMIMain(\@) {

    my $computer  = $_[0];
    my $action    = $_[1];
    my $rvalue    = $_[2];
    my $kvalue    = $_[3];
    
    my $WMI_Key     = "DeviceID";

    my $class = "WinMgmts://$computer";
    my $wmi = Win32::OLE->GetObject($class);
    
    my $i = 0;

    if ($wmi) {

        if ($action eq "index") {


            my $properties = "$WMI_Key";
            my $computers = $wmi->ExecQuery("SELECT $properties FROM $
+Win32_Class");


            if (scalar(Win32::OLE::in($computers)) lt "1") {
                print "\n    Check the computer and class name.\n";
                print   "    No information was found on the specified
+ class!\n";
                return;
            }

            foreach my $pc (Win32::OLE::in($computers)) {

                $i++;

                properties($pc,$properties);

                if ($i < scalar(Win32::OLE::in($computers))) {

                    print "\n";

                }
            }


        } # if action = index


        if ($action eq "query") {

            my $properties = "$WMI_Key,$rvalue";
            my $computers = $wmi->ExecQuery("SELECT $properties FROM $
+Win32_Class");


            if (scalar(Win32::OLE::in($computers)) lt "1") {
                print "\n    Check the computer and class name.\n";
                print   "    No information was found on the specified
+ class!\n";
                return;
            }

            foreach my $pc (Win32::OLE::in($computers)) {

                $i++;

                properties($pc,$properties);

                if ($i < scalar(Win32::OLE::in($computers))) {

                    print "\n";

                }
            }

        } # if action = query

        if ($action eq "get") {

            for(my $ID = 0; $ID < $kvalue; $ID++) {

                my $properties = $rvalue;
                my $computers = $wmi->ExecQuery("SELECT $properties FR
+OM $Win32_Class Where $WMI_Key='CPU$ID'");

                if($kvalue != 1) {
                    print "CPU$ID:";
                }

                if (scalar(Win32::OLE::in($computers)) lt "1") {
                    print "-1$output_delimeter";
                    #print "\n    Check the computer and class name.\n
+";
                    #print   "    No information was found on the spec
+ified class!\n";
                    #return;
                }

                foreach my $pc (Win32::OLE::in($computers)) {
                    properties($pc,$properties);

                    if($ID != ($kvalue - 1)) {
                        print "$output_delimeter";
                    }
                }
            }

        } # if action = get

        if ($action eq "browse") {


            my $properties = "*";
            my $computers = $wmi->ExecQuery("SELECT $properties FROM $
+Win32_Class");


            if (scalar(Win32::OLE::in($computers)) lt "1") {
                print "\n    Check the computer and class name.\n";
                print   "    No information was found on the specified
+ class!\n";
                return;
            }

            foreach my $pc (Win32::OLE::in($computers)) {

                $i++;

                properties($pc,$properties);

                if ($i < scalar(Win32::OLE::in($computers))) {

                    print "\n";

                }
            }


        } # if action = browse


    } # if wmi


    else {
        print "Unable to talk to WMI for $computer.\n";
    }
    
}

#Loop through an object's properties.
#Parameters:
#    0 - a reference to the object
#    1 - a single property to lookup

sub    properties($$) {
    my $node = $_[0];
    my $properties = $_[1];
    my $i = 0;

    if ($properties eq '*') {
        foreach ( Win32::OLE::in($node->{Properties_}) ) {
            viewPropertyBrowse($_);
            print "\n";

        }
    }

    else {


    my @properties = split(',', $properties);

    foreach (@properties) {

        $i++;

        if (scalar(@properties) eq "1") {

            viewProperty($node->{Properties_}->{$_});

        }

                elsif (scalar(@properties) gt "1") {


            viewPropertyMulti($node->{Properties_}->{$_});

            if ((scalar(@properties) gt "1") & $i lt (scalar(@properti
+es))) {
                print "$output_delimeter";
            }
        }
    }
    }    

}


#Display an object's property.
#Parameters:
#    0 - a reference to the property object

sub viewProperty($$) {
    my $object = $_[0];

        chomp ($object->{Value});
        print "$object->{Value}";

}


sub viewPropertyMulti($$) { 
   my $object = $_[0]; 

      chomp ($object->{Value}); 
      print "$object->{Name}:$object->{Value}";
#      print "$object->{Name}:".1024*$object->{Value}.""; 

} 

sub viewPropertyBrowse($$) { 
   my $object = $_[0]; 

      chomp ($object->{Value}); 
      print "$object->{Name}:$object->{Value}";
#      print "$object->{Name}:".1024*$object->{Value}.""; 

}

[download]
any suggestion or example code will be welcome.thanks in advance.

20050915 Janitored by Corion: Added readmore tags

Replies are listed 'Best First'.
Re: How to monitor a file located on the remote host(win2k)?
by ikegami (Patriarch) on Sep 15, 2005 at 15:10 UTC

    Nine things caught my eye in the 10s I spent looking at your node:

    1)
    $script_name[((scalar(@script_name)) - 1)]
    can be shortened to
    $script_name[@script_name - 1]
    and
    $script_name[$#script_name]
    and
    $script_name[-1]

    2) Why use an array for script_name? The following will do:
    my $script_name = (split m!\\!, $0)[-1];

    3) Windows also accepts "/" as a path seperator. Fix:
    my $script_name = (split m![\\/]!, $0)[-1];
    or better yet, the portable
    use File::Spec;
    my $script_name = (File::Spec->splitpath($0))[2];

    4) You use prototypes. Prototypes are discouraged; they should only be used when they are necessary.

    4)a) They are not necessary for WMIMain. You're even using the wrong prototype. The following will not work:

    WMIMain(@ARGV);

sub WMIMain(\@) {
    my $computer  = $_[0];
    my $action    = $_[1];
    my $rvalue    = $_[2];
    my $kvalue    = $_[3];
    ...

    [download]

    4) b) You are using prototypes on methods. They are not definitely not necessary there either, since prototypes don't even work (are ignored) when functions are called as methods.

    5) You're using user-provided, unvalidated, unescaped value ($kvalue and others) in a SQL commands.

    6) I think
    scalar(Win32::OLE::in($computers))
    should be
    scalar(@{Win32::OLE::in($computers)})

    7)
    scalar(@{Win32::OLE::in($computers)}) lt "1"
    won't do what you expect. Use
    scalar(@{Win32::OLE::in($computers)}) < 1
    or just
    @{Win32::OLE::in($computers)} < 1

    Same for eq "1" (== 1) and gt "1" (> 1).

    Use eq/ne/lt/gt for string comparisons. Use ==/!=/</> for numerical comparisons. This is documented in perlop.

    8)
    Win32::OLE::in($computers)
    can be simplified to
    in $computers
    if you do
    use Win32::OLE qw( in );
    at the top.

    Update: I spent another 10s looking at the code, and documented the additional problems I found. It seems you have problems with Perl, not just WMI. Do you have a specific question you'd like to have answered?

[reply]
[d/l]
[select]
      Thanks for your help. Acturally, this script work fine for me, what I concentrated about is using which WMI class and how to write the query code? as the following: 
      my $computers = $wmi->ExecQuery("SELECT $properties FROM $Win32_Class"
+);

      [download]
      for example, I would like to get the filesize of a file located on the remote host(OS:win2k, IP:192.168.100.22), and the full directory is "D:\poller.php". Any idea? anyway thanks ikegami. ;-)
[reply]
[d/l]
        hey guys, I have found the following vbs scripts from Microsoft, it can do the job, and I would like to convert it to perl. Is there anybody can help me? 
        strComputer = "192.168.100.17" 
Set objWMIService = GetObject("winmgmts:" _ 
    & "{impersonationLevel=impersonate}!\\" _ 
    & strComputer & "\root\cimv2") 
Set colFiles = objWMIService. _ 
    ExecQuery("Select * from CIM_DataFile where Name = 'D:\\languardns
+s6.exe'") 
For Each objFile in colFiles 
    Wscript.Echo "File Name: " & "." & objFile.Extension 
    Wscript.Echo "Path: " & objFile.Path & objFile.Name 
    Wscript.Echo "File Size: " & objFile.FileSize 
Next

        [download]
[reply]
[d/l]

Back to Seekers of Perl Wisdom