tainted
weaken
);
-our $VERSION = "1.31";
+our $VERSION = "1.32";
$VERSION = eval $VERSION;
our @EXPORT_FAIL;
By default C<Scalar::Util> does not export any subroutines. The
subroutines defined are
-=over 4
-
-=item blessed EXPR
+=head2 blessed EXPR
If EXPR evaluates to a blessed reference the name of the package
that it is blessed into is returned. Otherwise C<undef> is returned.
$obj = bless [], "Foo";
$class = blessed $obj; # "Foo"
-=item dualvar NUM, STRING
+Take care when using this function simply as a truth test (such as in
+C<if(blessed $ref)...>) because the package name C<"0"> is defined yet
+false.
+
+=head2 dualvar NUM, STRING
Returns a scalar that has the value NUM in a numeric context and the
value STRING in a string context.
$num = $foo + 2; # 12
$str = $foo . " world"; # Hello world
-=item isdual EXPR
+=head2 isdual EXPR
If EXPR is a scalar that is a dualvar, the result is true.
$err = dualvar $!, $!;
$dual = isdual($err); # true
-=item isvstring EXPR
+=head2 isvstring EXPR
If EXPR is a scalar which was coded as a vstring the result is true.
$fmt = isvstring($vs) ? "%vd" : "%s"; #true
printf($fmt,$vs);
-=item looks_like_number EXPR
+=head2 looks_like_number EXPR
Returns true if perl thinks EXPR is a number. See
L<perlapi/looks_like_number>.
-=item openhandle FH
+=head2 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(*NOTOPEN); # undef
$fh = openhandle("scalar"); # undef
-=item readonly SCALAR
+=head2 readonly SCALAR
Returns true if SCALAR is readonly.
$readonly = foo($bar); # false
$readonly = foo(0); # true
-=item refaddr EXPR
+=head2 refaddr EXPR
If EXPR evaluates to a reference the internal memory address of
the referenced value is returned. Otherwise C<undef> is returned.
$obj = bless {}, "Foo";
$addr = refaddr $obj; # eg 88123488
-=item reftype EXPR
+=head2 reftype EXPR
If EXPR evaluates to a reference the type of the variable referenced
is returned. Otherwise C<undef> is returned.
$obj = bless {}, "Foo";
$type = reftype $obj; # HASH
-=item set_prototype CODEREF, PROTOTYPE
+=head2 set_prototype CODEREF, PROTOTYPE
Sets the prototype of the given function, or deletes it if PROTOTYPE is
undef. Returns the CODEREF.
set_prototype \&foo, '$$';
-=item tainted EXPR
+=head2 tainted EXPR
Return true if the result of EXPR is tainted
$taint = tainted("constant"); # false
$taint = tainted($ENV{PWD}); # true if running under -T
-=item weaken REF
+=head2 weaken REF
REF will be turned into a weak reference. This means that it will not
hold a reference count on the object it references. Also when the reference
be destroyed because there is now always a strong reference to them in the
@object array.
-=item isweak EXPR
+=head2 isweak EXPR
If EXPR is a scalar which is a weak reference the result is true.
$copy = $ref;
$weak = isweak($copy); # false
-=back
-
=head1 DIAGNOSTICS
Module use may give one of the following errors during import.
projects / platform / upstream / perl.git / commitdiff