Optimise IPC::Open3 with a compile-time constant, eliminating OS-specific code.

($^O isn't going to change at run time, so why carry a lot of code that is
never going to get called on the platform you're running on.)

diff --git a/lib/IPC/Open3.pm b/lib/IPC/Open3.pm
index 815674b..a7365bd 100644 (file)
--- a/lib/IPC/Open3.pm
+++ b/lib/IPC/Open3.pm
@@ -9,7 +9,7 @@ require Exporter;
 use Carp;
 use Symbol qw(gensym qualify);
 
-$VERSION       = 1.04;
+$VERSION       = 1.05;
 @ISA           = qw(Exporter);
 @EXPORT                = qw(open3);
 
@@ -181,7 +181,7 @@ sub xfileno {
     return fileno $_[0];
 }
 
-my $do_spawn = $^O eq 'os2' || $^O eq 'MSWin32';
+use constant DO_SPAWN => $^O eq 'os2' || $^O eq 'MSWin32';
 
 sub _open3 {
     local $Me = shift;
@@ -225,7 +225,7 @@ sub _open3 {
     xpipe $dad_rdr, $kid_wtr if !$dup_rdr;
     xpipe $dad_err, $kid_err if !$dup_err && $dad_err ne $dad_rdr;
 
-    $kidpid = $do_spawn ? -1 : xfork;
+    $kidpid = DO_SPAWN ? -1 : xfork;
     if ($kidpid == 0) {                # Kid
        # A tie in the parent should not be allowed to cause problems.
        untie *STDIN;
@@ -272,7 +272,7 @@ sub _open3 {
            eval { require POSIX; POSIX::_exit(255); };
            exit 255;
        };
-    } elsif ($do_spawn) {
+    } elsif (DO_SPAWN) {
        # All the bookkeeping of coincidence between handles is
        # handled in spawn_with_handles.