Sync with Scalar-List-Utils-1.07

p4raw-id: //depot/perl@15283

4 files changed, 71 insertions, 2 deletions

diff --git a/ext/List/Util/ChangeLog b/ext/List/Util/ChangeLog
index 5ab668b155..934643ace1 100644
--- a/ext/List/Util/ChangeLog
+++ b/ext/List/Util/ChangeLog
@@ -1,3 +1,11 @@
+Change 713 on 2002/03/18 by <gbarr@pobox.com> (Graham Barr)
+
+	Add Scalar::Util::openhandle()
+
+Change 647 on 2001/09/18 by <gbarr@pobox.com> (Graham Barr)
+
+	Release 1.06
+
 Change 645 on 2001/09/07 by <gbarr@pobox.com> (Graham Barr)
 
 	Some platforms require the main executable to export symbols
diff --git a/ext/List/Util/lib/List/Util.pm b/ext/List/Util/lib/List/Util.pm
index 91dbcdb7b6..1843873e5e 100644
--- a/ext/List/Util/lib/List/Util.pm
+++ b/ext/List/Util/lib/List/Util.pm
@@ -11,7 +11,7 @@ require DynaLoader;
 
 our @ISA       = qw(Exporter DynaLoader);
 our @EXPORT_OK = qw(first min max minstr maxstr reduce sum shuffle);
-our $VERSION   = "1.06_00";
+our $VERSION   = "1.07_00";
 
 bootstrap List::Util $VERSION;
 
diff --git a/ext/List/Util/lib/Scalar/Util.pm b/ext/List/Util/lib/Scalar/Util.pm
index 1329d1a48a..e518a4c445 100644
--- a/ext/List/Util/lib/Scalar/Util.pm
+++ b/ext/List/Util/lib/Scalar/Util.pm
@@ -10,9 +10,27 @@ require Exporter;
 require List::Util; # List::Util loads the XS
 
 our @ISA       = qw(Exporter);
-our @EXPORT_OK = qw(blessed dualvar reftype weaken isweak tainted readonly);
+our @EXPORT_OK = qw(blessed dualvar reftype weaken isweak tainted readonly openhandle);
 our $VERSION   = $List::Util::VERSION;
 
+sub openhandle ($) {
+  my $fh = shift;
+  my $rt = reftype($fh) || '';
+
+  return defined(fileno($fh)) ? $fh : undef
+    if $rt eq 'IO';
+
+  if (reftype(\$fh) eq 'GLOB') { # handle  openhandle(*DATA)
+    $fh = \(my $tmp=$fh);
+  }
+  elsif ($rt ne 'GLOB') {
+    return undef;
+  }
+
+  (tied(*$fh) or defined(fileno($fh)))
+    ? $fh : undef;
+}
+
 1;
 
 __END__
@@ -69,6 +87,16 @@ If EXPR is a scalar which is a weak reference the result is true.
     weaken($ref);
     $weak = isweak($ref);               # true
 
+=item openhandle FH
+
+Returns FH if FH may be used as a filehandle and is open, or FH is a tied
+handle. Otherwise C<undef> is returned.
+
+    $fh = openhandle(*STDIN);		# \*STDIN
+    $fh = openhandle(\*STDIN);		# \*STDIN
+    $fh = openhandle(*NOTOPEN);		# undef
+    $fh = openhandle("scalar");		# undef
+    
 =item readonly SCALAR
 
 Returns true if SCALAR is readonly.
diff --git a/ext/List/Util/t/openhan.t b/ext/List/Util/t/openhan.t
new file mode 100644
index 0000000000..9eed5b9488
--- /dev/null
+++ b/ext/List/Util/t/openhan.t
@@ -0,0 +1,33 @@
+#!./perl
+
+BEGIN {
+    unless (-d 'blib') {
+	chdir 't' if -d 't';
+	@INC = '../lib';
+	require Config; import Config;
+	keys %Config; # Silence warning
+	if ($Config{extensions} !~ /\bList\/Util\b/) {
+	    print "1..0 # Skip: List::Util was not built\n";
+	    exit 0;
+	}
+    }
+}
+
+
+use Scalar::Util qw(openhandle);
+
+print "1..4\n";
+
+print "not " unless defined &openhandle;
+print "ok 1\n";
+
+my $fh = \*STDERR;
+print "not " unless openhandle($fh) == $fh;
+print "ok 2\n";
+
+print "not " unless fileno(openhandle(*STDERR)) == fileno(STDERR);
+print "ok 3\n";
+
+print "not " if openhandle(CLOSED);
+print "ok 4\n";
+