From VBScript to Win32::OLE ... "foreach"

[SparceMatrix]

I am using PERL, v5.8.7 built for MSWin32-x86-multi-thread from ActiveState.

This is my first attempt at PERL. I have written three or four small but hard working VBScripts using various objects guided

by O'Reilly's excellent "Windows 98 in a Nutshell". I would like to make use of PERL's superior RegExp features, but until I

get my first useful program going in PERL, I'd like to use the VBScript's RegExp in the Win32::OLE module.

I am stuck here:

This is easy in VBScript:

' VB Script Document

Option Explicit

Dim objFSO, objFileToWrite, objFolder  
Dim MyFile

Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFileToWrite = objFSO.CreateTextFile("FolderTEST.txt")
set objFolder = objFSO.GetFolder("MyFolder")

	For Each MyFile in objFolder.Files
		objFileToWrite.WriteLine(MyFile.name)
	Next
	
Set objFSO = nothing
Set objFileToWrite = nothing
Set objFolder = nothing

But in PERL below, I get syntax errors for the "foreach" area and I suspect it is because of the way I am applying the

collections returned by objFolder.Files in PERL:

#!/usr/bin/perl

use Win32::OLE;
#use strict;
use warnings;


$objFSO = Win32::OLE->new('Scripting.FileSystemObject');
$objFileToWrite = $objFSO->CreateTextFile("FolderTEST.txt");
$objFolder = $objFSO->GetFolder("MyFolder");


Foreach $MyFile (@objFolder)	{
	$objFileToWrite->WriteLine($MyFile->name);
	}

I have managed to go through ActiveStates PERL documentation for OLE here:

http://aspn.activestate.com/ASPN/docs/ActivePerl/5.8/site/lib/Win32/OLE.html

But, I can't seem to extract a clue there.

So, how do you get the "foreach" of PERL to work the same way as it does in VBScript for this particular case?

Any and all tips and clues would be appreciated.

 

[KevinADC]

'foreach' should be all lower case. All core perl functions are lower case.

 

[SparceMatrix]

That did it.

Well, that's kind of sad. None of the tutorials that I read or my Perl Pocket Reference seem to make any reference to this basic syntax.

Thank you.

 

[SparceMatrix]

Since this was so easy ...

Could somebody explain how you would add code to this so that you could properly enable "use strict"? Notice that I use "option explicit" in the VBScript code and somebody explained that briefly at another excellent coding forum for VBA, here:

http://www.vbaexpress.com/forum/

 

[SparceMatrix]

Apparently, depite removing the syntax errors, I'm not quite done yet. I look at the FolderTEST.txt file and see no file names in my test MyFolder folder. Also, I ommited "->files" in the PERL code I posted above:

#!/usr/bin/perl

use Win32::OLE;
#use strict;
use warnings;


$objFSO = Win32::OLE->new('Scripting.FileSystemObject');
$objFileToWrite = $objFSO->CreateTextFile("FolderTEST.txt");
$objFolder = $objFSO->GetFolder("MyFolder")[red] or die "Folder not found"[/red];


[red]foreach[/red] $MyFile ([red]@[/red]objFolder[red]->files[/red])    {
    $objFileToWrite->WriteLine($MyFile->name);
    }

I did change "foreach" and I did add "->files", but still no written files. I added the "or die" phrase to check to see if the folder is being opened. I do get a new "FolderTEST.txt" file. I've tried changing "$MyFile->name" to "$MyFile->{name}" and "$objFolder" to "@objFolder". A strange thing I notice is that the FolderTEST.txt file gets bigger to 1 KB, but has no text when you open it up.

So, why is the PERL version not functioning the same way as the VBScript? Am I missing something?

 

[chazoid]

You might actually find this easier to do in perl without using the OLE module. You'll need at least basic perl knowledge to use that module anyway. This is a very good (free) book to start with:

http://learn.perl.org/library/beginning_perl/

Also, get familiar with the HTML documentation that comes with ActivePerl.

ex: This will get a list of files in a directory then write the filenames to a text file.

use strict;
use warnings;

my $dir = 'c:/temp';
my $txt = 'output.txt';
my @files = glob("$dir/*.*");

# open file for writing
open ( my $fh_output, '>', $txt) or die $!;

foreach my $file ( @files ) {
    # if it's a file, print to output filehandle:
    if (-f $file) print $fh_output $file , "\n";
}
# close filehandle
close ( $fh_output );

To answer your question about strict, global variables aren't allowed under strict, so you have to declare them with "my". To view documentation for any function, either check the HTML docs under 'perlfunc' or at a command prompt type: perldoc -f <function name>

 

[SparceMatrix]

Thank you for writing that. I'll give it a try. I realize that VBScript is a pretty dim language compared to PERL. My hope was that since OLE is a module in PERL, that I might go deeper into PERL from the beginning using the similarities between VBS and PERL's OLE module as a point of orientation.

I suspect I am missing a few configurations or settings or something that prevent my posted PERL from working. By learning what needs to be changed or different, I can get an early yet firm grasp on Object Orientation in PERL.

Even more telling is that I have been applying VBScript strictly to use Regular Expressions. I might have started with PERL right away, but I had already been rapidly oriented in the book I mention above.

 

[KevinADC]

your script has:

$objFolder = ...

but then you use:

@objFolder->files

if $object is a reference to an array you need to use dereferencing, something like:

foreach $MyFile (@{$objFolder}) {
 do something with $MyFile
}

 

[SparceMatrix]

OK, I think I got it.

This works:

#!/usr/bin/perl

use Win32::OLE;
[red][b]use Win32::OLE qw(in with);[/b][/red]
use strict;
use warnings;


my $objFSO = Win32::OLE->new('Scripting.FileSystemObject');
my $objFileToWrite = $objFSO->CreateTextFile("FolderTEST.txt");
my $objFolder = $objFSO->GetFolder("MyFolder") or die "Hey! Folder not found";


foreach my $MyFile ([red][b]in[/b][/red] $objFolder->Files)	{
[green]#foreach my $MyFile (@$objFolder->Files)	{  	# DOES NOT WORK[/green] 	
	$objFileToWrite->WriteLine($MyFile->{name});
	}

Copy and paste this as a new script with MyFolder in the script directory and a few test files in it and you will see a list of those files show up in FolderTEST.txt when you run the script.

I stumbled accross this solution in ActiveState's usually excellent documentation that comes with their free download of PERL. I would say that they were a little amiss in not explaining this necessity more directly to anyone using OLE since that would be a natural lure to anyone coming from the excrutiatingly simple VBScript -- simple by comparison, I would say.

If you have their documentation installed, you can find the information under "ActivePerl FAQ" and there under "Windows Specific" and then finally "Using OLE with PERL".

The basic problem, I think, is that the thing returned by $objFolder->Files is neither a scalar nor an array. It is a "collection" and requries special treatment by way of the "use Win32::OLE qw(in with);" call. I cannot say what "qw() is, I just saw an example that showed its use.

Thanks to all who posted to lend a hand.

Comments?

 

[SparceMatrix]

chazoid:

You are missing the "{}" for the "if" statement here:

use strict;
use warnings;

my $dir = 'c:/temp';
my $txt = 'output.txt';
my @files = glob("$dir/*.*");

# open file for writing
open ( my $fh_output, '>', $txt) or die $!;

foreach my $file ( @files ) {
    # if it's a file, print to output filehandle:
    if (-f $file) [red][b]{[/b][/red] print $fh_output $file , "\n" [red][b]}[/b][/red];
}
# close filehandle
close ( $fh_output );

But also I am having a problem with this that is typical for a lot of my file handling code. If my directory has any spaces, then the variable carrying the directory becomes mangled. For example, if I used the directory 'C:/My Directory/My Other Directory' the output in the output.txt file was:

C:/My
Directory/My
Other
Directory

How do I cope with spaces in my directories?

Otherwise, I was able to get your code to work. Thanks.