Beefy Boxes and Bandwidth Generously Provided by pair Networks
Just another Perl shrine

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

G'day govindkailas,

It's generally not a good idea to export by default (i.e. with @EXPORT) — see the Exporter documentation sections: Selecting What to Export and What Not to Export. Instead, consider using @EXPORT_OK and %EXPORT_TAGS.

Here's an example of that does that:

package Utilities; use strict; use warnings; use Exporter qw{import}; my @sys_exports = qw{$SYS_DIR $SYS_OTHER}; my @util_exports = qw{$UTIL_THIS $UTIL_THAT}; our @EXPORT_OK = (@sys_exports, @util_exports); our %EXPORT_TAGS = (SYS => [@sys_exports], UTIL => [@util_exports]); our $SYS_DIR = "sys_dir"; our $SYS_OTHER = "sys_other"; our $UTIL_THIS = "util_this"; our $UTIL_THAT = "util_that"; 1;

Here's some sample runs showing how to use it.

No namespace pollution unless specifically requested:

$ perl -Mstrict -Mwarnings -E ' use Utilities; say $SYS_DIR; ' Global symbol "$SYS_DIR" requires explicit package name at -e line 3. Execution of -e aborted due to compilation errors.

Request a specific item:

$ perl -Mstrict -Mwarnings -E ' use Utilities qw{$SYS_DIR}; say $SYS_DIR; ' sys_dir

Request multiple items using a tag:

$ perl -Mstrict -Mwarnings -E ' use Utilities qw{:SYS}; say $SYS_DIR; ' sys_dir

Mix specific and tag requests:

$ perl -Mstrict -Mwarnings -E ' use Utilities qw{:UTIL $SYS_OTHER}; say $SYS_OTHER; say $UTIL_THAT; ' sys_other util_that

-- Ken

In reply to Re: Better way to define global variables by kcott
in thread Better way to define global variables by govindkailas

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others contemplating the Monastery: (4)
    As of 2018-06-25 07:06 GMT
    Find Nodes?
      Voting Booth?
      Should cpanminus be part of the standard Perl release?

      Results (126 votes). Check out past polls.