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

I'm setting up some scripts to be run by crontab.

Portability is an issue, so I'm doing my best to create a config file that will contain anything that may change in order to move the code.

I've managed this, with one exception. My scripts all use a common package. In order to get this into @INC I've been doing something like this: 

use strict;
use lib '/my/path/';
use PackageName;

our ( $var1, $var2);

require Config;

[download]
And it works fine. Now I'm trying to get this path into my config file like such: 
our ( $var1, var2, $myPath);

require SCP_Config;
use lib $myPath;
use PackageName;

[download]
And it doesn't work. I know that this is because 'use lib' is a compile-time command, which is causing problems.

Still, there must be a way to do this. Any ideas?

Thanks.

Replies are listed 'Best First'.
Re: Dynamic Package Loading
by ikegami (Patriarch) on Dec 16, 2005 at 20:23 UTC

    Why not use use SCP_Config instead of require SCP_Config? That will execute it at compile-time instead of at run-time.

    Actually, if SCP_Config doesn't contain package SCP_Config;, I'd use BEGIN { do 'SCP_Config.pm' }. do will allow multiple files to use SCP_Config, and BEGIN will cause it to execute at compile-time.

[reply]
[d/l]
[select]
Re: Dynamic Package Loading
by BrowserUk (Patriarch) on Dec 16, 2005 at 20:25 UTC

    Something like 

    BEGIN{
our $mypath;
require SCP_Config;
require lib $mypath;
}

    [download]

    Should do it. (untested)

    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
[d/l]
      This produced a syntax error near require lib $mypath;
[reply]
[d/l]

        Grrr. Of course it does. It needs to be like this 

        #! perl -slw
use strict;

our $path;
BEGIN {
    require SP_Config;
}
use lib $path;
print for @INC;

        [download]
        Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
        Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
        "Science is about questioning the status quo. Questioning authority".
        In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
[d/l]

Back to Seekers of Perl Wisdom