http://qs321.pair.com?node_id=281332
Category: Perl Administration
Author/Contact Info Soren Andersen <somian -AT- pobox *DOT* com> or <somian -AT- cpan *DOT* org>
Description:

This simple text-term program shows the breakdown of the Perl configuration belonging to that Perl interpreter being run (ordinarily "perl"). The utility of such a thing will not necessarily be obvious unless the user is an admin who is maintaining one or more Perl installations (more than one is possible per system), or a module author who is trying to write build infrastructure. In the author's experience, it is sometimes desireable to see at a glance the organization of the principle Perl installation directories. Being able to do so may be particularly advantageous when trying to install or upgrade modules and the installation is not going smoothly.

This script was developed on a system running a *nix-type OS (Linux, Debian 3.0r1) and tested against Perl versions 5.6.1 and 5.8.0.

Update:   Thu Aug 7 2003 15:05 UTC
Removed the code relying on File::Find and replaced it with a corrected, simpler subroutine. Perl Monk Aristotle helped direct my attention to that solution in the follow-up below.

Update:   Sun Aug 17 2003 14:03 UTC
Added the *man* dirs to the report. On most or all *nix-like platforms, we install manpages at module installation time, including in cygwin.

Also added a test to make sure a Win32 perl was looked for with .exe suffix. No previous reports from Win32 users had indicated a problem, but some edge case might require this care.

Update:   Sat Jan 10 2004 07:10 UTC
Considerable changes made but they only affect the formatting of the header slightly.

See download from Intrepid's perlmonk site for the most up-to-date release of this script.

Update:   Tue, 13 Feb 2007
The Intrepid perlmonk.org site has been partially rebuilt. See the following links offered for readers' convenience:


  • This script's "production copy" with cryptographic signature and all POD in-line: signed

#! /usr/bin/env perl
eval 'exec /usr/bin/perl  -S $0 ${1+"$@"}'
    if 0; # not running under some shell

=for gpg
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

=head1 NAME

showPerlDirConfig - explore (pretty-print) the basis of directory loca
+tions
of the Perl installation configuration matching the perl interpreter c
+urrently
being run.

=head2 VERSION

This POD documents

 ---------------------------------------------------------------------
                     * version 2004.01.09 *
 ---------------------------------------------------------------------

=head1 SYNOPSIS

 $ showPerlDirConfig
 $ /opt/bin/myfunkyperl showPerlDirConfig

=cut

# --------------------------------------------------------------------
+-
# internal CVS - RCS version control information:
## somian ## 1.7 ##
## 2004/01/10 01:54:28    ##
# --------------------------------------------------------------------
+-

use strict;
use Config;
use File::Spec;

$^W       = 1;
$\        = "\n";
my $Ll    = 0;
my $Stogg = 0;

my $headr =
  sub {
      my($perlFQpath,$stringL) = @{&pselfIdentity};
      my $margin = calc_midbuffs ($stringL => $Ll);
      my($decoL,$decoR) = ('','');
      if   ($margin >= 6)
      {
      $decoL = '||:' ; $decoR = ':||';
      }
      my $visi   = "$decoL   $perlFQpath   $decoR";
      my $spadd  = $margin - 3 - length $decoL;
         $spadd += length $visi;
      my $formtl = "%${spadd}s";
      print "Installation directory target configuration for "
       ,"the Perl binary installed as";
      printf $formtl => $visi;
      print "\n\n" , ( '-' x $Ll);
  };

## ***  <main execution> *** ##
print join "\n"
   =>(
 map { 
     my $keyarr=$_; # we get scoping confusion induced err if not.
     $Stogg++ || &$headr;
     my $ins=$Config::Config{$keyarr->[0]};
     my $ndi=substr($keyarr->[0],0,7) eq 'install'? "\n".('-'x$Ll):'';
     sprintf( "%-20s". " "x8 ."%s$ndi", $keyarr->[0], $ins )
     }
  sort { $a->[1] cmp $b->[1] }
  map [ $_, kenzoku($_) ],
  grep { /^(?!installusr|ta|mv|mu|d_)\w*
          (?:bin(?!compat)|arch(?!name|obj)|man(?:1|3)(?!ext)|priv|
          (?:vendor|site)(?!lib_|prefix))
          [a-z]*
         /x } keys %Config::Config
    );
exit;
## *** </main execution> *** ##

sub kenzoku  {
    my $mwa=shift;
    my $ins=$Config::Config{$mwa};
    $Ll = ($Ll <= length($ins)+28)? length($ins)+28 : $Ll;
    my $rwa=$mwa;
    $rwa =~s/^install// or $rwa =~s/exp$//;
    return
      $rwa .( substr($mwa,0,7) eq 'install'? 3 :
              substr($mwa,-3)  eq 'exp'?     2 : 1 );
}

sub pselfIdentity  {
    my $pintexe=$^X;
    unless( $Config::Config{exe_ext}
                  and
        substr($pintexe,-4) eq $Config::Config{exe_ext} )
    {
    $pintexe .= $Config::Config{exe_ext};
    }
    unless( File::Spec->file_name_is_absolute($pintexe) ) {
        $pintexe = (grep -x, map File::Spec->catfile($_,$pintexe)
           , split /\Q$Config::Config{path_sep}/, $ENV{PATH})[0];
    }
    return( [$pintexe , length $pintexe] );
}

sub calc_midbuffs
{
    my( $textW, $availW ) = @_ ;
    if (    $ENV{'COLUMNS'} and ($ENV{'COLUMNS'} > $availW)
        and ($textW > int(.9 * $availW))    )
    {
    $availW = $ENV{'COLUMNS'};
    }
    my $leew = $availW - $textW;
    return int( ($leew + 0.5) / 2 );
}

__END__

=head1 DESCRIPTION

This is a simple program written for the curious Perl newbie or the th
+orough
perl administrator (the system admin responsible for the installation 
+and
operating efficiency, and improvement thereof, and upgrades to, Perl..
+.) who
wants to know more about the internal layout of the important director
+ies
where Perl parts are kept.

Specifically, the program will display the directories where core and
site-extension perl modules are installed, allowing the prediction of 
+where
yet-to-be built modules are going to land when Perl's module installat
+ion
facilities are done with them.

=head2 NOTES

If the F<Config.pm> file read by your Perl interpreter during operatio
+n is
hosed (incorrect, tampered with, or invalid due to a binary being comp
+iled on
a different system), then the resulting data displayed by this program
cannot be trusted. Garbage in, garbage out.

=head1 SEE ALSO

L<ExtUtils::MakeMaker>, L<Config>, L<perl>

=head1 AUTHOR & CREDITS

Soren Andersen E<lt>C<somian -AT- pobox *DOT* com>E<gt> a.k.a
E<lt>C<somian -AT- cpan *DOT* org>E<gt> is responsible for all badness
+.
However Perl Monks "castaway" and "Aristotle" helped to point him towa
+rds
solutions that led to an improved script.

This release is cryptographically signed. The author / maintainers' Gn
+uPG/OpenPGP
key is identified by No. C<0x4E244EA6> and should be locateable for ve
+rification
on keyservers worldwide. "perlsign" (modified code) was used as the si
+gning tool.

=head1 COPYRIGHT AND LICENSE

Copyright 2003,2004 by Soren Andersen, U.S.A.

This program is Free software; you may redistribute it and/or modify i
+t under the
same terms as Perl itself (See the F<LICENSE> file in your Perl source
+ kit). Part
of that license stipulates that you, the user, agrees that this Free s
+oftware is
accepted "AS-IS" and comes with absolutely NO WARRANTY, not even the i
+mplied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

=head4 Any POD appearing below this line are merely entries for suppor
+t of
L<the CPAN Scripts Repository|http://www.cpan.org/scripts/index.html> 
+and its automata.

=begin text

 -----------------------------------------------------------------

=end text

=begin html

<hr>

=end html

=pod OSNAMES

any

=pod SCRIPT CATEGORIES

UNIX : System_administration
CPAN

=cut

=begin gpg

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