requiring perl modules

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

This is a simple question for all you perl geniuses. I'm trying to require code in a separate directory off my main directory. I have tried so many different variations to get this to work. I've even tried to push '.\\modules' onto the @INC array before calling require. Nothing works. Can someone help?

$dir = 'modules';
$mod = 'test';
$pkg = sprintf("%s::%s",$dir,$mod);
require $pkg;

print test::func(), "\n";
[download]

#code in modules\test.pm
package test;

sub func()
{
  print "hello from test\n";
}
1;
[download]

thanks, Michael

Comment on requiring perl modules Select or Download Code

Replies are listed 'Best First'.
Re: requiring perl modules by chromatic (Archbishop) on Dec 03, 2003 at 17:59 UTC
According to require, if the argument to `require` is not a bareword (if it's a variable as you have or an expression returning a name), Perl doesn't automatically add the `.pm` extension. I suspect you could get by with something like this: `use File::Spec; my $dir = 'modules'; my $mod = 'test'; my $module = File::Spec->catfile( $dir, $mod . '.pm' ); require $module;` [download] The documentation also suggests this, which I don't like, though it is shorter: `eval "require $mod";`	[reply] [d/l] [select]
Re: Re: requiring perl modules by ysth (Canon) on Dec 03, 2003 at 19:28 UTC
It was my recollection that require expected (or at least allows) a posix-style pathname, e.g. `require "$dir/$mod.pm"`. Could someone on VMS or a Mac try with catfile, with '/', and via eval "require $mod" and report which work (as well as what they put in %INC)? I would find it very helpful to know for sure.	[reply] [d/l]
Re: requiring perl modules by hardburn (Abbot) on Dec 03, 2003 at 18:02 UTC
As covered in the require documentation, when `require` gets a string (instead of a bare statement), it doesn't automatically translate the '::' for you. You'll need to change your code to one of the following: `# Change the sprintf . . . $pkg = sprintf("%s/%s", $dir, $mod); # . . . OR change the require to be inside an eval eval "require $pkg";` [download] In the second form, the expanded variable looks like a bare statement to `require`, so the '::' translation works. ---- I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident. -- Schemer `: () { :\|:& };:` Note: All code is untested, unless otherwise stated	[reply] [d/l] [select]
Re: requiring perl modules by Zed_Lopez (Chaplain) on Dec 03, 2003 at 19:17 UTC
Just enter `perl -V` to examine your @INC list. It probably includes '.', i.e. the current directory, in which case, like the Anonymous Monk above, `require modules::test` will work. Or you can `use lib '.\modules'` (equivalent to unshifting @INC, only in a BEGIN block) and then `require test`. Or, unless there's some reason you need to defer loading the module, just: `use lib '.\modules'; use test;` [download]	[reply] [d/l] [select]
Re: requiring perl modules by Anonymous Monk on Dec 03, 2003 at 18:57 UTC
try require modules::test; It works for me.	[reply]