Re: Dots and cargo-cult programming

[joefission]

I've got a slightly different take on the . vs -> syntax grumblings.

I have Win32 System Administration background. I was told by someone I deeply respected, that I should learn Perl if I wanted to be a "real sys admin" (curiously he didn't mention the OS...too easy a target, I guess). There are quite a few tools out there that use VB and VBScript for NT Admins. I laughed at people who used VB because, well, it was BASIC (yeah, just a tad naive).

However, quite a few books and people use VB for examples on how to script NT administration tasks. One of these books is ADSI ASP Programmer's Reference(1998,wrox, Steven Hahn). I wanted to know more about ADSI and this book had lots of info, even with it being VB-centric. I figured I could port it to Win32::OLE. I was wrong. I didn't want to learn VB so I could learn how to do it in Perl. So this book doesn't even have the spine cracked, because I found other Perl modules aside from OLE to keep me busy.

I'm very embarrassed to say that I had no idea that . meant -> until it was brought up in the Perl6 discussions. I guess I can go back, break open that book, and translate the . to ->.
If Perl6 uses the . syntax, it might make it easier for people like me to read and learn from other code. Even if it is VB.

[rchiav]

That understanding will help you, but there will be other differences. For instance, this.that = 2 in VB would be $this->{that} = 2 in Perl. But something like a method call would be this->DoSomething.

Using Win32::OLE isn't as straightforward as you might want it to be. The biggest things to look out for is that when you're setting properties, you're going to be using a hash, and there are other times when you're going to be using lists. For example..

This is some DB code that uses ADO..

#!/usr/bin/perl -w

use strict;
use Win32::OLE;

my $strCon = "Provider=SQLOLEDB; Data Source=XXXXX; Initial Catalog=SM
+S; "
    . "User ID=XXXXX; Password=XXXXX";
    
my $strSql = "SELECT System_DATA.Name0, datediff(dd, LastUpdateDate, g
+etdate())" 
    . " 'age' FROM SoftwareInventoryStatus INNER JOIN System_DATA on "
     . "System_Data.MachineID = SoftwareInventoryStatus.ClientID WHERE
+ "
     . "(datediff(dd, LastUpdateDate, getdate()) > 30)" ;
    
my $objCon = new Win32::OLE("ADODB.Connection");
my $objRecordset = new Win32::OLE("ADODB.Recordset");

$objCon->{'ConnectionString'} = $strCon;
$objCon->Open;

$objRecordset->Open($strSql, $objCon);

while (not $objRecordset->{'EOF'}) {
    print $objRecordset->{'Name0'}{'Value'}, "\t";
    print $objRecordset->{'age'}{'Value'}, "\n";
    $objRecordset->MoveNext;
}

$objRecordset->Close;
$objCon->Close;

and someting similar in VB (sorry, this below is from some ASP a customer asked me to put together. Above is something I use. They don't perform the same task, but you should be able to see what mirrors what.

Option Explicit
Dim objConnection, objRecordset, strSQL, Name

Set objConnection = Server.CreateObject("ADODB.Connection")
objConnection.ConnectionString  = "Provider=SQLOLEDB; Data Source=XXXX
+; Initial Catalog=SMS; User ID=XXXX; Password=XXXX"
objConnection.Open

Set objRecordset = Server.CreateObject("ADODB.Recordset")
strSQL = "SELECT Name0, MachineID FROM System_DATA WHERE  MachineID >=
+ 0 ORDER BY Name0"
objRecordset.Open strSQL, objConnection

and what was a little confusing to figure out is that in VB, You can refrence the "Name0" field as objRecordset("Name0") but in Perl it's $objRecordset->{'Name0'}{'Value'} I personally prefer Perl, but with things like Win32::OLE it's a lot of poke and hope to figure out just how you have to access properties and methods.