Re: module location

That's because the assigment of $perl_module doesn't happen until runtime, while the use happens at compile time.

You basically have two options:

Move assignement to compile time

my $perl_module;
BEGIN {$perl_module = shift};
eval "use $perl_module";
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Move loading of module to runtime

(my $filename = "$perl_module.pm") =~ s#::#/#g;
require $filename;
$perl_module->import;
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The first has the disadvantage that you need to eval a string. If you can't trust the parameter input, that may be a security issue.

The latter has the disadvantage that you must convert the module name to a filename. But you need the original module name to be able to do the import().

Hope this helps.

Liz

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Re: Re: module location by hmerrill (Friar) on Nov 07, 2003 at 15:43 UTC
This is driving me nuts - I don't understand why this doesn't work: `#!/usr/bin/perl -w use strict; my $perl_module; BEGIN { my $ct_args = @ARGV; if ($ct_args != 1) { print "\nUsage: pwhich_short <perl module name>\n\n"; print "Example: pwhich_short DBI\n\n"; exit; } $perl_module = shift; }; eval "use $perl_module" or die "Can't find $perl_module: $!\n";` [download] This code gets this error: `Can't find DBI:` [download] That's it. Does this work for you? Any ideas? Thanks.	[reply] [d/l] [select]
Re: Re: Re: module location by liz (Monsignor) on Nov 07, 2003 at 15:50 UTC
I think you want to replace: `eval "use $perl_module" or die "Can't find $perl_module: $!\n";` [download] by: `eval "use $perl_module"; die "Can't find $perl_module: $@\n" if $@;` [download] Eval just returns whatever was returned by `use`, which to my knowledge is undefined (please someone correct me if I'm wrong). You need to check whether $@ is non-empty after the eval(). Liz	[reply] [d/l] [select]
Re: Re: Re: Re: module location by hmerrill (Friar) on Nov 07, 2003 at 16:23 UTC
Liz, you get the gold star! It works - I've used eval before, but mostly just in DBI transaction code where I had an eval block({}) and then checked $@ after, but I guess I forgot that for any eval errors you need to check $@. Thank you very much! Hardy	[reply]