PERL5LIB-How does it work

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

Hello,
This is a question for my edification. I had thought that if one puts a directory in PERL5LIB, perl would search that director and all subdirectories for modules. I had in my .profile

PERL5LIB=\
/hdb10/Perl/PerlLibs/lib/perl5/5.8.8/:\
/hdb10/Perl/PerlLibs/lib/perl5/site_perl/5.8.8/:

Perl couldn't find Tagset.pm. I used find and found it was dir under the HTML directory, and so I added a third line

PERL5LIB=\
/hdb10/Perl/PerlLibs/lib/perl5/5.8.8/:\
/hdb10/Perl/PerlLibs/lib/perl5/site_perl/5.8.8/:\
/hdb10/Perl/PerlLibs/lib/perl5/site_perl/5.8.8/HTML

and it worked. Would someone be so kind as explain the rules for seaching for modules.
Thanks in advance for any help
klee12

Comment on PERL5LIB-How does it work

Replies are listed 'Best First'.
Re: PERL5LIB-How does it work by Corion (Patriarch) on Sep 18, 2007 at 06:57 UTC
Your error is that, in your program, you have the line: `use TagSet;` [download] where you should have the line `use HTML::TagSet;` [download] Then, the original setting of PERL5LIB would work as advertised. The package is named HTML::TagSet, so Perl goes looking for a file `HTML/TagSet.pm` below each entry in PERL5LIB (or rather, `@INC`, which gets amended by PERL5LIB.	[reply] [d/l] [select]
Re^2: PERL5LIB-How does it work by Anonymous Monk on Sep 18, 2007 at 18:22 UTC
Thanks Corion. Actually I wasn't using the Tagset.pm. I encountered it while installing libwww-perl-5.808.tar.gz and it complained it couldn't find Tagset. I used find . -name "Tagset*" and got ./lib/perl5/site_perl/5.8.8/i486-linux-thread-multi/auto/HTML/Tagset ./lib/perl5/site_perl/5.8.8/HTML/Tagset.pm The first line referred to an empty directory. I'm not sure if this is a bug. If someone thinks it is a bug, perhaps they could report it. Thanks again. klee12	[reply]
Re: PERL5LIB-How does it work by bruceb3 (Pilgrim) on Sep 18, 2007 at 06:50 UTC
I am the human manual. `$ perldoc -t perlrun \| less +/PERL5LIB` [download] PERL5LIB A list of directories in which to look for Perl library files before looking in the standard library and the cur- rent directory. Any architecture-specific directories under the specified locations are automatically included if they exist. If PERL5LIB is not defined, PERLLIB is used. Directories are separated (like in PATH) by a colon on unixish platforms and by a semicolon on Windows (the proper path separator being given by the command "perl -V:path_sep"). When running taint checks (either because the program was running setuid or setgid, or the -T switch was used), nei- ther variable is used. The program should instead say: use lib "/my/directory";	[reply] [d/l]
Re^2: PERL5LIB-How does it work by Anonymous Monk on Sep 18, 2007 at 18:06 UTC
Thanks,bruceb3. I found that but didn't read it carefully. That seems to say that it looks only at the files in the directory unless there is are "architecture-specific directories". Since they descended into "archtecure-specific directories" I had assumed they descended into all directories. klee12	[reply]
Re: PERL5LIB-How does it work by ikegami (Patriarch) on Sep 18, 2007 at 18:14 UTC
The module should be located at `.../site_perl/5.8.8/HTML/Tagset.pm`. The module should be loaded using `use HTML::Tagset;`. Sounds like the module is incorrectly located at `.../site_perl/5.8.8/HTML/HTML/Tagset.pm`, or the module is incorrectly loaded using `use Tagset;`. Adding `.../site_perl/5.8.8/HTML` to `@INC` in order to omit `HTML::` from the `use` directive is bound to lead to problems.	[reply] [d/l] [select]


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