I suspect you are using __END__where what you really meant was exit;.

  1. First perlhas to read your script file and produce the under-the-covers code it will execute; this is sometimes called "compilation" and sometimes "interpretation" (the latter is more technically correct);
  2. Then perlhas to execute the code it created during the interpretation phase.

So these two keywords have different functions:

Thus, your __END__is causing perlto stop reading the source code before it gets to the subroutine; the subroutine is therefore never compiled. During execution, it does not exist, hence the error.

So, if I'm guessing right about your intentions, the fix is fairly simple, as noted by everyone else on this thread: 

package My::Util;

use strict;
use warnings;
use Exporter;
our @ISA = qw(Exporter);
our @EXPORT = qw( get_file_name );

exit;
sub get_file_name {
    ...
}

1;

__END__

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In reply to Re: Subroutines not exporting? Why? by marinersk
in thread Subroutines not exporting? Why? by no21

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