Sharing Getopts::Std amongst several related scripts

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

Howdy,

Here is my scenario:

I have about a dozen or so scripts that perform related (but each slightly different) tasks.
And I have a single library of common functions, which each of the above scripts requires
Currently, none of the scripts accept command-line options, but I now need to add this functionality.
As each of the scripts perform (almost) identical functions, and will hence accept the same command-line switches, I thought it would make more sense to add the code for reading these into the library, rather than each individual script.

So far, so good (I think)... So I started playing around with Getopts:Std. I added code to my library like so:

use Getopt::Std;
getopts('fs', \%opts);
[download]

I found that if I then referred to %opts from within the library, like so:

if ($opts{s}) { #do stuff }
[download]

...it all works as expected. But if I try to refer to %opts from outside the library, I get:

Global symbol "%opts" requires explicit package name.....
[download]

The reason for the error is pretty obvious - the script doesn't know about %opts, and as I'm using strict, it barfs. But I'm not sure where to go from here. I'm guessing that I need to create a package, and refer to that - but I'm afraid that this is uncharted territory for me. I've tried putting this:

{
    package FOO;
    use Getopt::Std;
    getopts('fs', \%opts);
}
[download]

in the library, but that doesn't work.

Can somebody point me in the right direction please?

Thanks,
Darren :)

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Re: Sharing Getopts::Std amongst several related scripts by ikegami (Patriarch) on Dec 13, 2005 at 15:35 UTC
Use a package (`our`) variable instead of a lexical (`my`) variable: `package main; use Getopt::Std; our %opts; getopts('fs', \%opts); package Foo; if ($main::opts{s}) { #do stuff } package Bar; if ($main::opts{s}) { #do stuff }` [download] You can even create an alias: `package main; use Getopt::Std; our %opts; getopts('fs', \%opts); package Foo; our %opts; opts = \%main::opts; if ($opts{s}) { #do stuff } package Bar; our %opts; opts = \%main::opts; if ($opts{s}) { #do stuff }` [download] I hate referencing main explicitely, so I prefer importing the symbol from a module that will handle the options: `# Optionally in seperate file Opts.pm package Opts; use Getopt::Std; our %opts; our @EXPORT = qw( %opts ); our @ISA = 'Exporter'; require Exporter; getopts('fs', \%opts); 1; package Foo; use Opts qw( %opts ); if ($opts{s}) { #do stuff } package Bar; use Opts qw( %opts ); # Safe to do multiple times. if ($opts{s}) { #do stuff }` [download]	[reply] [d/l] [select]
Re^2: Sharing Getopts::Std amongst several related scripts by McDarren (Abbot) on Dec 13, 2005 at 16:15 UTC
Thank you very much for such a comprehensive answer :) I've changed the code in my library to look like so: `{ package OPTS; use Getopt::Std; our %opts; getopts('fs', \%opts); }` [download] and in the script that requires the library, I have: `our %opts; *opts = \%OPTS::opts; if ($OPTS::opts{f}) { #do stuff }` [download] and it all seems to work now the way I want it to. Although I'm still not really sure I fully understand what's going on here. I've just been flicking through Chapter 10 (Packages) in my trusty Camel Book. I think I need to study it some more before I get the hang of this. But thanks again :)	[reply] [d/l] [select]
Re^3: Sharing Getopts::Std amongst several related scripts by ikegami (Patriarch) on Dec 13, 2005 at 17:31 UTC
`our %opts; opts = \%OPTS::opts; if ($OPTS::opts{f}) { #do stuff }` [download] can be simplified to `if ($OPTS::opts{f}) { #do stuff }` [download] or `our %opts; opts = \%OPTS::opts; if ($opts{f}) { #do stuff }` [download]	[reply] [d/l] [select]