Set environment variable PERL5LIB to the directory list that you want in your @INC.

set PERL5LIB=\perl\lib;\perl\site\lib
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. is automatically added, so don't need to worry about it.

If I do:

set PERL5LIB=foo;bar;%PERL5LIB%
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The last piece of perl -V shows:

......
  %ENV:
    PERL5LIB="foo;bar;\perl\lib;\perl\site\lib"
  @INC:
    foo
    bar
    \perl\lib
    \perl\site\lib
    .
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What do you copy to the new computer? Just perl.exe or the whole bin directory? Do you update the PATH system variable?

This is all on the same computer. I am not relying on my PATH to run perl and I am just copying perl.exe and the perl56.dll. I ran dependency walker and that is the only dynamically linked non-OS library linked in perl.exe.

I was always under the impression that the @INC variable is fixed once you compile perl.exe but there was on thread here that mentioned it seems to be somewhat dynamic but not in the way I'm finding out. That thread seemed to indicate that moving perl.exe around would result in @INC being adjusted so the directories it contains have their path adjusted accordingly.

In my attempts to mimick this problem I got an error about missing Config.pm when running perl -V when I removed all the perl except perl.exe and perl58.dll and perl5.8.0.exe (Yes I am doing this under perl 5.8 because that is all I have on Win32). The config.pm that it is refering to (I think) is c:\perl\lib\Config.pm and it contains alot of the info needed for the -V screen. I don't know if this helps you.

@INC is the result of all perllib additions that have been made by perl upon startup. It is not fixed at all. Although there is a portion of it that is fixed at compile time. The @INC is a combination of compile time settings, PERLLIB environment variable, perl command line -I parameters and use lib statements.

For example on linux, if you do:

PERLLIB=envbar perl -I cmdfoo -V -e "use lib ('usebaz');"

You will see the resulting @INC :

  @INC:
    usebaz
    cmdfoo
    envbar
    /usr/lib/perl5/5.6.1/i386-linux
    /usr/lib/perl5/5.6.1
    /usr/lib/perl5/site_perl/5.6.1/i386-linux
    /usr/lib/perl5/site_perl/5.6.1
    /usr/lib/perl5/site_perl/5.6.0/i386-linux
    /usr/lib/perl5/site_perl/5.6.0
    /usr/lib/perl5/site_perl
    /usr/lib/perl5/vendor_perl/5.6.1/i386-linux
    /usr/lib/perl5/vendor_perl/5.6.1
    /usr/lib/perl5/vendor_perl
    .
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There appears to be an order of precidence here too. use lib is first, -I option is second, PERLLIB is third and compiled settings is fourth.

Update: added use lib to the example.

Hazah! I'm Employed! But this place sucks

Note: I'm doing a lot of handwaving here... I seem to recall having read about this, but I've not looked it up to confirm my beliefs. I'll look it up later, I promise.

I was always under the impression that the @INC variable is fixed once you compile perl.exe

That's right. That's even the case for Perl on Windows... Except: perl itself changes the directories found in the hardwired @INC inside the perl exectutable, into directories relative to where it currently resides. That happens to lib (relative position to perl: ../lib) and site/lib (relative position: ../site/lib), where the perl executable resides in bin, relative to the perl installation root.

You could say it's a simple s/^$HARDWIRED_ROOT/$CURRENT_ROOT/, done inside perl.

  bin/
  lib/
  site/lib
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C:\Documents and Settings\jim> C:\Progra~1\Perl\Perl561_638\bin\perl.e
+xe -V
Summary of my perl5 (revision 5 version 6 subversion 1) configuration:

....

  Built under MSWin32
  Compiled at Apr 13 2004 19:24:21
  @INC:
    C:/Program Files/Perl/Perl561_638/lib
    C:/Program Files/Perl/Perl561_638/site/lib
    .


C:\Documents and Settings\jim>mkdir bin

C:\Documents and Settings\jim>cp C:\Progra~1\Perl\Perl561_638\bin\perl
+.exe bin\.

C:\Documents and Settings\jim>cp C:\Progra~1\Perl\Perl561_638\bin\perl
+56.dll bin\.

C:\Documents and Settings\jim>set PATH=C:\Documents and Settings\jim\b
+in;%PATH%

C:\Documents and Settings\jim>perl.exe -V
Can't locate Config.pm in @INC (@INC contains: .).
BEGIN failed--compilation aborted.

C:\Documents and Settings\jim>mkdir lib

C:\Documents and Settings\jim>mkdir site\lib

C:\Documents and Settings\jim>perl.exe -V
Can't locate Config.pm in @INC (@INC contains: C:/Documents and Settin
+gs/jim/lib
 C:/Documents and Settings/jim/site/lib .).
BEGIN failed--compilation aborted.
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C:\Documents and Settings\jim>del bin\perl56.dll

C:\Documents and Settings\jim>perl -V
Summary of my perl5 (revision 5 version 6 subversion 1) 

  ...

ActivePerl Build 638
  Built under MSWin32
  Compiled at Apr 13 2004 19:24:21
  @INC:
    C:/Program Files/Perl/Perl561_638/lib
    C:/Program Files/Perl/Perl561_638/site/lib
    .
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As a follow-up:

The relevant parts of the .c code appear to be in win32.c

char *win32_get_sitelib(const char *pl)
{
    return win32_get_xlib(pl, "sitelib", "site");
}


static char *win32_get_xlib(const char *pl, const char *xlib, const ch
+ar *libname)
{

 ....

    sprintf(pathstr, "%s/lib", libname);
    (void)get_emd_part(&sv2, pathstr, ARCHNAME, "bin", pl, Nullch);

    /* JJ -- get_emd_part strips 'bin' if possible from 
             the path to the .dll (found in get_emd_part
             by calling set_w32_module_name(); ) and then
             adds 'site/lib' to that path
     */

 ...
}
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Thanks so much. What you describe is definitely the behavior I see. I didn't realize the perl executable would make the @INC directories relative to the location of the dll and if they weren't found it wouldn't include them. It's kind of annoying that perl.exe locates the perl5x.dll via %PATH%; I'd prefer it was done through the registry, but I digress.

Thanks for the help!