[Bast-commits] r3749 - local-lib/1.000/trunk/lib/local

[apeiron at dev.catalyst.perl.org]

Author: apeiron
Date: 2007-09-16 03:21:04 +0100 (Sun, 16 Sep 2007)
New Revision: 3749

Modified:
   local-lib/1.000/trunk/lib/local/lib.pm
Log:
o   Refactored shell detection into something a bit more easily-extendable, and
    general cleanups in that department.

o   Additional docs stating when you'd use this and a more accurate description
    of what this actually does. Also enumerate the environment variables that
    are changed on import, and let the user know that if they try to be a wise
    guy and forget to define $SHELL that they'll be given Bourne commands as a
    default.

o   Much -- or rather most -- of this work was done in direct cooperation with
    mst++ who taught me more than a thing or two about how perl works as we
    discussed the shell refactoring. I merely did the typing. Thanks, mst.


Modified: local-lib/1.000/trunk/lib/local/lib.pm
===================================================================
--- local-lib/1.000/trunk/lib/local/lib.pm	2007-09-15 23:08:43 UTC (rev 3748)
+++ local-lib/1.000/trunk/lib/local/lib.pm	2007-09-16 02:21:04 UTC (rev 3749)
@@ -202,6 +202,7 @@
   my ($class, $path) = @_;
   my @envs = $class->build_environment_vars_for($path, LITERAL_PATH);
   my $out = '';
+
   # rather basic csh detection, goes on the assumption that something won't
   # call itself csh unless it really is. also, default to bourne in the
   # pathological situation where a user doesn't have $ENV{SHELL} defined.
@@ -212,20 +213,41 @@
       my @shell_bin_path_parts = File::Spec->splitpath($ENV{'SHELL'});
       $shellbin = $shell_bin_path_parts[-1];
   }
+  my $shelltype = do {
+      local $_ = $shellbin;
+      if(/csh/)
+      {
+          'csh'
+      }
+      else
+      {
+          'bourne'
+      }
+  };
+
   while (@envs) {
     my ($name, $value) = (shift(@envs), shift(@envs));
     $value =~ s/(\\")/\\$1/g;
-
-    if($shellbin =~ /csh/) {
-      $out .= qq{setenv ${name} "${value}"\n};
-    }
-    else {
-      $out .= qq{export ${name}="${value}"\n};
-    }
+    $out .= $class->${\"build_${shelltype}_env_declaration"}($name, $value);
   }
   print $out;
 }
 
+# simple routines that take two arguments: an %ENV key and a value. return
+# strings that are suitable for passing directly to the relevant shell to set
+# said key to said value.
+sub build_bourne_env_declaration {
+  my $class = shift;
+  my($name, $value) = @_;
+  return qq{export ${name}="${value}"\n};
+}
+
+sub build_csh_env_declaration {
+  my $class = shift;
+  my($name, $value) = @_;
+  return qq{setenv ${name} "${value}"\n};
+}
+
 sub setup_env_hash_for {
   my ($class, $path) = @_;
   my %envs = $class->build_environment_vars_for($path, INTERPOLATE_PATH);
@@ -276,6 +298,10 @@
 
   use local::lib '~/foo'; # same, but ~/foo
 
+  # Or...
+  use FindBin;
+  use local::lib "$FindBin::Bin/../support";  # app-local support library
+
 From the shell -
 
   $ perl -Mlocal::lib
@@ -310,11 +336,37 @@
 environment variable), suitable for directly adding to one's shell configuration
 file.
 
+More generally, local::lib allows for the bootstrapping and usage of a directory
+containing Perl modules outside of Perl's C<@INC>. This makes it easier to ship
+an application with an app-specific copy of a Perl module, or collection of
+modules. Useful in cases like when an upstream maintainer hasn't applied a patch
+to a module of theirs that you need for your application.
+
+On import, local::lib sets the following environment variables to appropriate
+values:
+
+=over 4
+
+=item MODULEBUILDRC
+
+=item PERL_MM_OPT
+
+=item PERL5LIB
+
+=item PATH
+
+PATH is appended to, rather than clobbered.
+
+=back
+
+These values are then available for reference by any code after import.
+
 =head1 LIMITATIONS
 
 Rather basic shell detection. Right now anything with csh in its name is
 assumed to be a C shell or something compatible, and everything else is assumed
-to be Bourne.
+to be Bourne. If the C<SHELL> environment variable is not set, a
+Bourne-compatible shell is assumed.
 
 Bootstrap is a hack and will use CPAN.pm for ExtUtils::MakeMaker even if you
 have CPANPLUS installed.