How to get module to execute as standalone.

[billy]

I've seen it somewhere but cannot recall.
I have a module that I call from several difference files. call it
x.pl
I need to have this module also be an executable. The part I've seen
is that there
is an eval in the file that takes the command line arguments and passes
them to the
subroutine.

????

package x;
....

`eval $0 "use x; x(@ARGV);`

I know it can be done, just not sure how.

 

[Anno Siegel]

I've seen it somewhere but cannot recall.
I have a module that I call from several difference files. call it
x.pl

What's a "difference file"? Or do you mean "several different files"?

I need to have this module also be an executable. The part I've seen
is that there
is an eval in the file

Which file?

that takes the command line arguments and passes
them to the
subroutine.

????

package x;
...

`eval $0 "use x; x(@ARGV);`

I know it can be done, just not sure how.

I'm not sure what eval() is supposed to buy you here.

If you want a Perl module (a .pm file) to be runnable as a plain script,
put the script code under a condition that skips it if caller() is defined.
It will only run if the file is *not* loaded as a module.

For example, put this in x.pm:


#!/usr/bin/perl
use strict; use warnings; $| = 1; # @^~`

if ( !defined caller ) {
print "Running as a script\n";
x::func();
}

############################################################

package x;

# Exporter boilerplate goes here

sub func {
print "func() called\n";
}

1;


This file can be used as a module:

perl -Mx -e'x::func()'

and as a stand-alone script:

perl x.pm

Anno

 

[brian d foy]

I've seen it somewhere but cannot recall.
I have a module that I call from several difference files. call it
x.pl
I need to have this module also be an executable.

I talk about modules as scripts (which I called 'modulinos") in a
Perlmonks post: http://www.perlmonks.org/index.pl?node_id=396759

And also in an article for The Perl Journal:
http://www.tpj.com/documents/s=9621/tpj0411e/0411e.html

You may have seen this stuff before in the diagnostics.pm module.

Good luck.
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