The use function happens at compile time and must take a bareword, but it
is functionally equivalent to
BEGIN { require Module; Module->import( LIST ); }
And the require function allows you to pass a string, but be aware there
are lots of differences in behavior when passing a string vs a bareword:
https://perldoc.perl.org/functions/require
On Mon, Dec 14, 2020, 10:57 Jim Gibson <[email protected]> wrote:
> I have not used it myself, but the ‘if’ module allows one to load modules
> conditionally:
>
> use if CONDITION, MODULE => ARGUMENTS;
>
> See ‘perldoc if’ for more details.
>
>
> > On Dec 14, 2020, at 7:23 AM, Gary Stainburn <
> [email protected]> wrote:
> >
> > I've written my first re-usable modules in Perl, and all goes well.
> However, I want to know if / how I can use a string variable in the 'use'
> clause.
> >
> > In PHP I have a simple system of turning on/off debugging and version
> control. Any file *1.html is development version. I then have
> >
> > $DEBUG=(preg_match('/1.htm/',$_SERVER['REQUEST_URI'])) ? '1' : '';
> > include_once("sql$DEBUG.inc");
> > include_once("security$DEBUG.inc");
> >
> > This way I have a live and a development version of every HTML and every
> inc file, and putting any one file is simply a case of copying that file
> over.
> >
> > I'm looking to replicate this in Perl. How can I do the following?
> >
> > #!/usr/bin/perl -w
> >
> > use warnings;
> > use strict;
> >
> > my $DEBUG=($0=~/1$/) ? '1' : '';
> > use RW::Sql$DEBUG;
> > use RW::Docs$DEBUG;
> >
> > I've found that you can use "require" and pass a path. I understand
> that require is run time, while use is compile time. Are there any
> down-sides to using require?
> >
> > --
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> > http://learn.perl.org/
> >
> >
>
> Jim Gibson
>
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> http://learn.perl.org/
>
>
>
