Well, I've had a go... and I'm managing to get some of this module code working and I'm understanding it as well :) Thus, I've decided to code-up some example usage to illustrate what I've found out.

Here's what I have so far:

# Q.pl - mainline code

use Q2 qw($myfile func1 $SM_HDR_REC);

# ----

printf("\$Q2::myfile: >$Q2::myfile<\n");
printf("\$Q2::myport: >$Q2::myport<\n"); # Not exported but still
                                         # usable by fully-specifying

printf("\$myfile: >$myfile<\n"); # Ok 'coz it's exported
printf("\$myport: >$myport<\n"); # Unknown 'coz not exported

printf("SM_HDR_REC: >$SM_HDR_REC<\n"); # Declared 'our' in Q2.pm

# ----

$buf = "test_string";
printf("\nFn call into temp var:\n");
printf("String before: %s\n", $buf);
$newbuf = func1($buf);                        # Works!
printf("String  after: %s\n\n", $newbuf);

$buf = "test_string";
printf("Fn call only:\n");
printf("String before: %s\n", $buf);
printf("String  after: %s\n\n", func1($buf)); # Doesn't work!?


# Q2.pm - module code

package Q2;

use strict;
use Exporter;

# ----

use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);

$VERSION     = 1.00;
@ISA         = qw(Exporter);
@EXPORT      = ();
@EXPORT_OK   = qw($myfile &func1 &func2
                  $SM_HDR_REC);
%EXPORT_TAGS = (DEFAULT => [qw(&func1)],
                all     => [qw(&func1 func2 $myfile)]);

# ----

use vars qw($myfile $myport);

$myfile = 'FRED.DAT';  # Used locally and exported (above)
$myport = "OPA0:";     # Used locally but not exported

# ----

our $SM_HDR_REC = "HDR";

# ----

sub func1  { return reverse @_  }

sub func2  { return map{ uc }@_ }

END { };

1;
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The only question I have is the call to func1 -- the two calls in the mainline program above give different results. Is there something with how the function is being called or exported... or am I missing something obvious?

John