perl -Mstrict -Mwarnings -e "print join(',', %INC)"
__END__
Carp.pm,C:/usr/perl/lib/Carp.pm,warnings.pm,
C:/usr/perl/lib/warnings.pm,
Exporter.pm,C:/usr/perl/lib/Exporter.pm,
strict.pm,C:/usr/perl/lib/strict.pm
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PS> You're asking about the values, not the keys ;-)
PPS> The -M are used to load some modules, otherwise %INC is empty.

--
I'm not belgian but I play one on TV.

You're asking about the values, not the keys ;-)

Actually, I think the original poster was asking about the keys and not the values.

If your code does this ...

use LWP::Simple;

... then once the Simple.pm file has been located via @INC the pathname will be stored in %INC as the value associated with the key 'LWP/Simple.pm'.

It is my understanding that a package name is always converted to a key by replacing '::' with '/' and appending '.pm' regardless of the naming conventions of the platform where the code is running. The full pathname to the file (ie: the value in %INC) is in a platform dependent format.

So the answer to the original question: No the keys in %INC are not OS dependent.

I've wanted to do this to convince perl that a module was already loaded. In fact I'd gotten the impression that it was stored in unix-form regardless of the platform but I guess I'm wrong. Oops! But definately the keys.

A few more things have been patched in MacPerl, in order to increase portability, so even stuff like

    do "LWP/Simple.pm";
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The normal file path separator on the Mac is ":". By contrast to Windows, "/" normally would not work. I distinctly recall being involved in a discussion about all this on the MacPerl mailing list a few years ago, but I'm currently still unsuccessful in tracing it back in the archives.
Update: Found it!

I have no idea on the situation on that other even more special case, VMS.

    require Foo::Bar;    # a splendid bareword

The require function will actually look for the ``Foo/Bar.pm'' file in
+ the directories specified in the @INC array.
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MJD says "you can't just make shit up and expect the computer to know what you mean, retardo!"

I run a Win32 PPM repository for perl 5.6.x and 5.8.x -- I take requests (README).

** The third rule of perl club is a statement of fact: pod is sexy.

You could find out yourself if you have access to a couple of different platforms:

# UNTESTED
print join("\n", keys(%INC), "\n");
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--Bob Niederman, http://bob-n.com

Thanks for the replies - some folks have got the wrong idea though - I am talking about %INC keys, not values. Values will, of course, be OS dependent.

perldoc perlvar discusses this:

  The hash %INC contains entries for each filename included
  via the "do", "require", or "use" operators.  The key is 
  the filename you specified (with module names converted to
  pathnames), and the value is the location of the file 
  found. The "require" operator uses this hash to determine 
  whether a particular file has already been included.

From grantrn and bart's replies it certainly looks like it's OS independent, and that makes far more sense to me.

I'm going to perlbug this though, because I don't think the documentation is clear enough.

Thanks everyone for your replies.