How can I include a module for Windows only??

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

Replies are listed 'Best First'.
Re: How can I include a module for Windows only?? by broquaint (Abbot) on Dec 17, 2003 at 14:52 UTC
Just check the `$^O` variable (see. `perlvar` for more info) e.g `BEGIN { if($^O =~ /^Win/) { require Win32::Setupsup; Win32::Setupsup->import; } else { require Expect; Expect->import } }` [download] HTH `_________ broquaint`	[reply] [d/l]
Re: How can I include a module for Windows only?? by Benedictus (Beadle) on Dec 17, 2003 at 15:55 UTC
You can use the if module to "use" another module if a condition is true. In your case, you might have: `use if ($^O =~ /Win/i), "Win32::Setupsup"; use if ($^O !~ /Win/i), "Expect";` [download] Warning: the above code is untested. The "if" module should come with Perl, but you can get it from CPAN if need be. Benedictus	[reply] [d/l]
Re: How can I include a module for Windows only?? by edoc (Chaplain) on Dec 17, 2003 at 15:00 UTC
..just a shot in the dark here, but what if you split up the eval into 2? `BEGIN { eval{ require Expect; import Expect; }; eval{ require Win32::Setupsup; import Win32::Setupsup; } }` [download] I think when windows fails to require Expect, it's bailing from the eval and not getting to the require Win32 stuff.. update: hmmm.. ++broquaint cheers, J	[reply] [d/l]
Re: Re: How can I include a module for Windows only?? by pijush (Scribe) on Dec 17, 2003 at 16:21 UTC
Hi Monks! Thanks a lot. I have tried only with two eval blocks and it works fine with me. Thanks ++broquaint. Thanks all the monks who have helped me to resolve my problem. -Pijush	[reply]
Re: How can I include a module for Windows only?? by davido (Cardinal) on Dec 17, 2003 at 18:18 UTC
Others have answered the direct question. I liked broquaint's solution best because, instead of trapping an error in an eval, it just makes a decision based on the OS. Just one other thought though. It seems that if you continue down this road you're going to have a lot of "`if ( $^O =~ /^Win/ ) {...} else {...}`" logic scattered throughout the program. It may be advantageous to write a module that handles all this for you. The module would serve as an OS-independant wrapper interface that inherits from the OS-dependant modules you're using. Here's what I was thinking: (Warning, this is untested pseudocode): package UniWin; BEGIN { if ( $^O =~ /^MSWin/ ) { require Win32::Setupsup; import Win32::Setupsup; @ISA = qw/Win32::Setupsup/; } else { require Expect; import Expect; @ISA = qw/Expect/; } } # Here you write a OS-generic wrapper around any OS # specific uses of Win32::Setupsup and Expect. # For example, if Setupsup has a "Win_This()" method and # Expect has a "Unix_This()" method, you would write a # wrapper called This() which invokes either method # depending on which OS you're using... 1; package main; use strict; use warnings; use UniWin; # ..........The rest of the program goes here... [download] This has the advantage of creating an OS-generic interface to whichever module you ended up loading in an OS-dependant fashion. That will allow the remainder of your code to concentrate on just doing things one way. That's just a thought... Dave	[reply] [d/l] [select]
Re: Re: How can I include a module for Windows only?? by bart (Canon) on Dec 17, 2003 at 18:45 UTC
Much like File::Spec. I rather like that approach.	[reply]
Re: How can I include a module for Windows only?? by ysth (Canon) on Dec 17, 2003 at 20:06 UTC
The problem with your original code is probably that the require Expect is failing so it never gets to the require Win32::Setupsup. For an easy fix, put the two in separate evals. Or you can say: `use if $^O=~/Win/, "Win32::Setupsup"; use if $^O!~/Win/, "Expect";` [download] IIRC, if.pm is in every perl version > 5.6.1 except 5.8.0, and is also available from cpan. Update: I noticed a couple of posts saying /^Win/, which is wrong: $ fgrep osname= hints/.sh /config* hints/epix.sh:osname='epix2' hints/linux.sh:# The DR2 of MkLinux (osname=linux,archname=ppc-linux) +may need hints/mpeix.sh:osname='mpeix' hints/os400.sh: osname=aix hints/qnx.sh: *) osname='nto' Cross/config.sh-arm-linux:osname='linux' NetWare/config.wc:osname='NetWare' Porting/config.sh:osname='dec_osf' epoc/config.sh:osname='epoc' plan9/config_sh.sample:osname='plan9' win32/config.bc:osname='MSWin32' win32/config.gc:osname='MSWin32' win32/config.vc:osname='MSWin32' win32/config.vc64:osname='MSWin32' wince/config.ce:osname='MSWin32' [download] It is MSWin32 (even on 64-bit windows, I think).	[reply] [d/l] [select]


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