Problem understanding how to use modules

texan4ever has asked for the wisdom of the Perl Monks concerning the following question:

I am attempting to use a module I downloaded from CPAN. I am on a unix system where I dont have root permissions. So the CPAN module will have to go in my home directory.

I untarred the CPAN module here:
/users/<myusername>/perl/Tk-DKW-0.03

I ran the make file. It put the module files at:
Tk-DKW-0.03/blib/lib/Tk

I went to the example directory:
Tk-DKW-0.03/examples

Then I edited one of the examples and put a use statement at the top:

#! /usr/bin/perl

use lib "/users/<myusername>/perl/Tk-DKW-0.03/blib/Tk";
use Tk::Menustrip;
[download]

I then get this error:

(attocs951:examples)#482 ./menustrip.pl
Can't locate Tk/Menustrip.pm in @INC (@INC contains: "/users/<myuserna
+me>/perl/Tk-DKW-0.03/blib/lib/Tk /usr/lib64/perl5/5.8.5/x86_64-linux-
+thread-multi /usr/lib/perl5/5.8.5 /usr/lib64/perl5/site_perl/5.8.5/x8
+6_64-linux-thread-multi /usr/lib64/perl5/site_perl/5.8.4/x86_64-linux
+-thread-multi  . . . . .
[download]

If I do a ls of the directory I see the modules:

ls /users/<myusername>/perl/Tk-DKW-0.03/blib/lib/Tk

total 208K
4.0K CheckBox.pm*            12K Menustrip.pm*
4.0K ChildNotification.pm*  4.0K ProgressIndicator.pm*
 60K Columns.pm*            4.0K Signals.pm*
 12K ComboEntry.pm*          16K SplitFrame.pm*
8.0K CornerBox.pm*          8.0K TabbedForm.pm*
 20K DockFrame.pm            16K TabFrame.pm*
 28K IconCanvas.pm*          12K TableEdit.pm*
[download]

I dont understand what I am doing wrong.

Comment on Problem understanding how to use modules Select or Download Code

Replies are listed 'Best First'.
Re: Problem understanding how to use modules by bart (Canon) on Nov 19, 2013 at 22:33 UTC
I ran the make file. It put the module files at: `Tk-DKW-0.03/blib/lib/Tk` And that's where you left it. You ran the makefile. But you didn't install it. That's why the module is in such a weird place. It was never the idea to have a separate file tree for every module you install. It was the intention to have at most a few roots containing the modules you need. If you want to have the module under your home directory, then install it there. local::lib might be a handy too for it.	[reply] [d/l]
Re: Problem understanding how to use modules by daxim (Curate) on Nov 19, 2013 at 21:22 UTC
`use lib "/users/<myusername>/perl/Tk-DKW-0.03/blib";` is correct. Perl wants to load Tk/Menustrip.pm, so the directory name must end in blib, not blib/Tk. Better solution: don't edit the example and simply set the include path from the commandline: `$ cd /users/<myusername>/perl/Tk-DKW-0.03 $ perl -Mblib examples/checkbox.pl` [download] See blib. Update: this half-installed directory setup is only useful for testing. If you want to use Tk-DKW productively, you must install the distribution. local::lib helps you to set up the necessary environment variables so that the `make install` will target your home directory, not the system location where you have no write permission.	[reply] [d/l] [select]
Re: Problem understanding how to use modules by kennethk (Abbot) on Nov 19, 2013 at 21:17 UTC
I think you mean `use lib "/users/<myusername>/perl/Tk-DKW-0.03/blib/lib";` [download] The `use Tk::Menustrip;` looks for `Tk/Menustrip.pm` in the directories listed in @INC, not `Menustrip.pm`. See require, whose mechanism underlies use. #11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.	[reply] [d/l] [select]
Re: Problem understanding how to use modules by Anonymous Monk on Nov 19, 2013 at 21:36 UTC
I had tried both blib/lib/Tk and blib/lib. I then noticed with one configuration it complained about not finding Tk. So then I changed the #! /usr/bin/perl statement at the top of the example to what I ususally use on this system: `eval '(exit $?0)' && eval 'exec perl -S $0 ${1+"$@"}' & eval 'exec perl -S $0 $argv:q' if 0;` [download] then it worked	[reply] [d/l]
Re: Problem understanding how to use modules by taint (Chaplain) on Nov 20, 2013 at 06:47 UTC
Somewhat along the lines of bart's comment; If I were you. I'd create a folder in your Home dir, along the lines of: `~/lib` Then you can unpack your modules into a temp folder, and `cd /tmp/ModuleName perl Makefile.PL make make test make install PREFIX=~/lib` [download] Some suggest that you should indicate `PREFIX=` when you issue `perl Makefile.PL` eg; `perl Makefile.PL PREFIX=~/lib` [download] But I've never had any issues simply issuing it during the `make install` process. Best wishes --Chris OH. One more thing. Do remember to include the `lib` dir in your programs (`@INC`) (Perl scripts), eg; `use lib ('~/lib');` [download] #!/usr/bin/perl -Tw use Perl::Always or die; my $perl_version = (5.12.5); print $perl_version;	[reply] [d/l] [select]