conditionally include a module

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: conditionally include a module by FunkyMonk (Bishop) on Aug 23, 2007 at 08:53 UTC
As well as the require method already mentioned, there's also a standard module for this, if: `use if ($^O eq 'MSWin32'), 'Win32::OLE';` [download]	[reply] [d/l] [select]
Re^2: conditionally include a module by sgt (Deacon) on Aug 23, 2007 at 09:50 UTC
standard strictly above 5.6.1 `% steph@apexPDell2 (/home/stephan) % % perl -MModule::CoreList -e 'print Module::CoreList->first_release(q[ +if])' 5.006002` [download] cheers --stephan	[reply] [d/l]
Re^3: conditionally include a module by DrHyde (Prior) on Aug 23, 2007 at 10:04 UTC
Standard strictly above 5.7.2 and in 5.6.2 :-) `$ corelist -a if if was first released with perl 5.006002 5.006002 0.03 5.007003 0.01 5.008 0.01 5.008001 0.03 5.008002 0.03 5.008003 0.03 5.008004 0.03 5.008005 0.03 5.008006 0.03 5.008007 0.03 5.008008 0.05 5.009 0.03 5.009001 0.0401 5.009002 0.0401 5.009003 0.05 5.009004 0.05 5.009005 0.05` [download] Also note that "if was first released with perl 5.006002" is incorrect - it was first released with perl 5.7.3 in March 2002. 5.6.2 was released in November 2003.	[reply] [d/l]
Re: conditionally include a module by GrandFather (Saint) on Aug 23, 2007 at 08:46 UTC
Probably you want something like: `if ($^O eq 'MSWin32') { require Win32::OLE; }` [download] Note that $ENV{OSTYPE} is not cross platform. DWIM is Perl's answer to Gödel	[reply] [d/l]
Re^2: conditionally include a module by syphilis (Archbishop) on Aug 23, 2007 at 11:44 UTC
Note that $ENV{OSTYPE} is not cross platform Interestingly enough, there's a post just appeared on comp.lang.perl.misc pointing out that $^O is writable (can be modified) - on Windows, at least. I guess if we wanted to dot all of our i's and cross all of our t's we'd have to warn about that, too ... and recommend using $Config::Config{osname} (which actually is readonly) instead. Cheers, Rob Afterthought: Heh ... then again, $Config::Config{osname} can always be modified using `tied` ....	[reply] [d/l]
Re: conditionally include a module by Corion (Patriarch) on Aug 23, 2007 at 08:48 UTC
See use: It is exactly equivalent to `BEGIN { require Module; import Module LIST; }` So, do just that, except possibly without the `BEGIN` block, if you want to delay the decision further: `# use Win32::OLE; # becomes if ($^O eq 'MSWin32') { # dunno about Cygwin require Win32::OLE; Win32::OLE->Option( Warn => 3 ); # to get quicker/better feedback +on errors };` [download]	[reply] [d/l] [select]
Re^2: conditionally include a module by ForgotPasswordAgain (Vicar) on Aug 23, 2007 at 10:09 UTC
Just a little note on top of that. The `import` is what handles arguments you normally pass to `use`, so if you do something like: `use Whatever::Module qw(funky);` [download] you have to add a `Whatever::Module->import(qw(funky));` after your `require`.	[reply] [d/l] [select]
Re: conditionally include a module by ambrus (Abbot) on Aug 23, 2007 at 09:41 UTC
use if # it's a core module	[reply]