Re: Problem with ``use if COND, Some::Module'' on Linux

" ... (some code returning an empty list in list context?) ... "

Nothing to do with Proc::Daemon, but with the pattern match that returns an empty list:

use strict;
use warnings;

use if scalar ( $^O !~ /Win32/ ), 'Proc::Daemon';
use if scalar ( $^O =~ /Win32/ ), 'Win32::Daemon';

print $INC{'Proc/Daemon.pm'};
exit;

__END__
[download]

Output:

perl 1159936.pl
/Users/nick/perl5/perlbrew/perls/perl-5.22.0/lib/site_perl/5.22.0/Proc
+/Daemon.pm
[download]

Hope this helps!

Updated: force scalar context so we can keep pattern matches

The way forward always starts with a minimal test.

Comment on Re: Problem with ``use if COND, Some::Module'' on Linux Select or Download Code

Replies are listed 'Best First'.
Re^2: Problem with ``use if COND, Some::Module'' on Linux by stevieb (Canon) on Apr 08, 2016 at 17:39 UTC
Yep, that works if I do `ne 'MSWin32'`, but I'm very curious to know why my way works on Windows but not on nix. The whole reason for the `!~, =~` is so I don't have to check for both `MSWin32` and `MSWin64`.	[reply] [d/l] [select]
Re^3: Problem with ``use if COND, Some::Module'' on Linux by VinsWorldcom (Prior) on Apr 08, 2016 at 19:41 UTC
Not for nothing, but is 'MSWin64' an actual OS string? I'm on Windows 7 x64 with Strawberry Perl 5.22 64-bit and $^O still returns "MSWin32" for me. `VinsWorldcom@C:\Users\VinsWorldcom> ver Microsoft Windows [Version 6.1.7601] VinsWorldcom@C:\Users\VinsWorldcom> perl -v This is perl 5, version 22, subversion 1 (v5.22.1) built for MSWin32-x +64-multi-thread [...] VinsWorldcom@C:\Users\VinsWorldcom> perl -e "print $^O" MSWin32` [download]	[reply] [d/l]
Re^3: Problem with ``use if COND, Some::Module'' on Linux by stevieb (Canon) on Apr 08, 2016 at 17:45 UTC
The following works... `my $is_win = $^O =~ /MSWin/ ? 1 : 0; use if $is_win, 'Win32::Daemon'; use if ! $is_win, 'Proc::Daemon';` [download]	[reply] [d/l]
Re^4: Problem with ``use if COND, Some::Module'' on Linux by Laurent_R (Canon) on Apr 08, 2016 at 17:51 UTC
Do you really need a ternary operator here? I would think that: `my $is_win = $^O =~ /MSWin/;` [download] works the same way, doesn't it?	[reply] [d/l]
Re^5: Problem with ``use if COND, Some::Module'' on Linux by Anonymous Monk on Apr 08, 2016 at 19:30 UTC
Re^3: Problem with ``use if COND, Some::Module'' on Linux by 1nickt (Canon) on Apr 08, 2016 at 17:48 UTC
Updated to force scalar context on the pattern match output. The way forward always starts with a minimal test.	[reply]