problem with paths to library files

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

Please help ! urgent need to know:
what is the best practice on using :
use lib <path_to_libs>;
?
I have a live and beta website and wish to use the same code on both sites with as little changing as possible - I do not want to change the paths continually to point to the relevant website library (live or beta).
Therefore how can I achieve this ?
currently I am using:

use FindBin qw/$RealDir/;
BEGIN {$RealDir .="libs";}
use lib "$RealDir";
[download]

which I am not satisfied or happy with.
The live and beta websites reside on the same server - hence I cannot add the lib path into the @inc permanently (?or can I add both live and beta? I doubt.)

many thanks, oh wise ones,
johnc

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Re: problem with paths to library files by ferreira (Chaplain) on Jan 17, 2007 at 09:43 UTC
Maybe you don't need `use lib` at all, if you are able to set environment variables visible to your live and beta websites (possibly customized for each of these). If that's the case, you can add some paths to `@INC` automatically by setting the `PERL5LIB` variable. Read more about it in the section "ENVIRONMENT" on perlrun.	[reply] [d/l] [select]
Re: problem with paths to library files by themage (Friar) on Jan 17, 2007 at 09:52 UTC
hi j_c, In your case you have to options (that I know), depending on your environment . If your script is cgi your can use: `BEGIN { my $path=$0; $path=~s{[^\/]+$}{libs/}; } use lib $path;` [download] On the other hand, if your site is using ModPerl, you can configure your libpath in the httpd.conf (or similar) using: `<virtualhost *:80> # ... PerlSetVar libpath "/path/to/your/libs/"; </virtualhost>` [download] And then read that config with: `BEGIN { my $path=$r->dir_config("libpath"); } use lib $path;` [download] Hope this help. TheMage Magick Source Talking Web	[reply] [d/l] [select]
Re^2: problem with paths to library files by almut (Canon) on Jan 17, 2007 at 11:04 UTC
`BEGIN { my $path=$0; $path=~s{[^\/]+$}{libs/}; } use lib $path;` [download] The "minor" problem with this is that the lexical `$path` will already be out of scope in the `use lib $path;` statement (so the (empty) global `$path` is being used instead...) Moving the `my $path;` before the BEGIN block does work, though. (Honestly, I'm somewhat surprised it does (you might argue the BEGIN block is being executed before the lexical is brought into existence - but apparently this is not the case...). Would any of the more knowledgable Monks care to comment on whether this is a feature you can rely on?)	[reply] [d/l] [select]
Re^3: problem with paths to library files by j_c (Novice) on Jan 17, 2007 at 11:24 UTC
I tried moving the `my $path` above the begin but it didn't work... however, we have succeeded with the following: `use vars qw/$RealDir/; BEGIN{ $0 =~ m/(.*\/)/;#location of this file $RealDir = $1 . "libs"; }; use lib "$RealDir";` [download] which works a treat. thanks guys, excellent advice :) all the best johnc	[reply] [d/l] [select]
Re^4: problem with paths to library files by almut (Canon) on Jan 17, 2007 at 12:52 UTC
Re: problem with paths to library files by eff_i_g (Curate) on Jan 17, 2007 at 14:59 UTC
Why not something like the following (i.e., you don't need the BEGIN block)? `use FindBin; use lib "$FindBin::Bin/libs";` [download]	[reply] [d/l]