current path in a package?

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

How can a package knows which path it is in?

For example, I have a "test.pm" in "/www/somedir":

package test;
sub currDIR {
   use Cwd;
   print getcwd();
}

and then a "main.cgi" in "/www":

require "./somedir/test.pm";
test::currDIR();

running main.cgi will print me "/www" (path to main.cgi), however, I a
+ctually want "/www/somedir" (path to test.pm) instead, which command 
+should I use?  I'm asking this because I need to open certain files i
+n the package, and those files are stored in the same directory as th
+e package for portability issues.  Thank you.
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Re: current path in a package? by tilly (Archbishop) on Dec 28, 2010 at 06:41 UTC
Check perldata for __FILE__ which gives you the full filename of the current file. File::Spec's splitpath should give you the directory that that file is in. (Or you can parse it out yourself pretty easily, if you don't care about portability.)	[reply]
Re^2: current path in a package? by Anonymous Monk on Dec 28, 2010 at 07:44 UTC
Thanks a lot tilly!	[reply]
Re: current path in a package? by samarzone (Pilgrim) on Dec 28, 2010 at 08:06 UTC
If you are using `require` with a physical path to the module file you already know the path. If you are concerned with absolute path rather than relative one you can use `getcwd()` prepended to the relative path mentioned in the `require` statement. If you will `use` the module rather than `require`ing it you will find absolute path of module file into `%INC` hash variable with key as the module name. `use lib '/www/somedir/' use test; print $INC{test};` [download] -- Regards - Samar	[reply] [d/l] [select]
Re^2: current path in a package? by ELISHEVA (Prior) on Dec 28, 2010 at 08:34 UTC
Tilly suggested using `__FILE__` because using `cwd` is not necessarily reliable. A script might have changed the current directory after it has been loaded. Additionally, a module can be loaded from any of the paths in `@INC` and may never have been reachable via the current directory in the first place. Note: `__FILE__` only works for packages defined in the current file. If you want to find the location of an arbitrary package, look up the package in `%INC`. `%INC` contains a set of entries like this: `Carp.pm => '/usr/share/perl/5.8/Carp.pm' vars.pm => '/usr/share/perl/5.8/vars.pm' List/Util.pm => '/usr/lib/perl/5.8/List/Util.pm'` [download] In `%INC` the module name gets ".pm" tacked onto the end and all of the '::' are replaced by '/'. I believe this transformation is consistent across platforms, so to look up the location of an arbitrary package: `my $k = $module_name; $k =~ s/::/\//g; $k .= '.pm'; my $path = $INC{$k};` [download] .	[reply] [d/l] [select]