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head

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L<Examples| file:../examples/index.podlite>


L<Download |file:../download/index.podlite>


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=begin React :component<HeaderCol> :id<menu> 
=para L<Documentation|/doc/introduction>
=para L<Modules| /mods>
=para L<Examples| file:../examples/index.podlite>
=para L<Download |file:../download/index.podlite>
=para L<About|file:../about/index.podlite>
=para 🔍 K<⌘K>/K<ctrl-K>
=end React


HEADER

FOOTER

README

use v6.d;

unit module P5ref:ver<0.0.7>:auth<zef:lizmat>;

proto sub ref(|) is export {*}
multi sub ref() { ref CALLERS::<$_> }
multi sub ref(\this) {
    my \what = this<>.WHAT;         # decontainerize
    what =:= Array
      ?? 'ARRAY'
      !! what =:= Hash
        ?? 'HASH'
        !! what =:= Regex
          ?? 'Regexp'
          !! what ~~ Callable       # don't expect to be subclassing Callable
            ?? 'CODE'
            !! what =:= Version
              ?? 'VSTRING'
              !! this.VAR.^name eq 'Proxy'
                ?? 'SCALAR'
                !! this.^name         # whatever else
}



This module tries to mimic the behaviour of Perl's C<ref> built-in as
closely as possible in the Raku Programming Language.


HEAD1

ref EXPR
ref     Returns a non-empty string if EXPR is a reference, the empty
        string otherwise. If EXPR is not specified, $_ will be used. The
        value returned depends on the type of thing the reference is a
        reference to.


SCALAR
ARRAY
HASH
CODE
REF
GLOB
LVALUE
FORMAT
IO
VSTRING
Regexp


You can think of "ref" as a "typeof" operator.


if (ref($r) eq "HASH") {
    print "r is a reference to a hash.\n";
}
unless (ref($r)) {
    print "r is not a reference at all.\n";
}


The return value "LVALUE" indicates a reference to an lvalue that
is not a variable. You get this from taking the reference of
function calls like "pos()" or "substr()". "VSTRING" is returned
if the reference points to a version string.


The result "Regexp" indicates that the argument is a regular
expression resulting from "qr//".


If the referenced object has been blessed into a package, then
that package name is returned instead. But don't use that, as it's
now considered "bad practice". For one reason, an object could be
using a class called "Regexp" or "IO", or even "HASH". Also, "ref"
doesn't take into account subclasses, like "isa" does.


Instead, use "blessed" (in the Scalar::Util module) for boolean
checks, "isa" for specific class checks and "reftype" (also from
Scalar::Util) for type checks. (See perlobj for details and a
"blessed/isa" example.)


The following strings are currently never returned by C<ref> because they have
no sensible equivalent in Raku: C<REF>, C<GLOB>, C<LVALUE>, C<FORMAT>, C<IO>.


Also, since everything in Raku is a (blessed) object, you can only get the
C<SCALAR> response if you managed to put a Scalar container into another
Scalar container (which is pretty hard), or you somehow have gotten ahold of
a Proxy object.  On all other cases, a Scalar container will be ignored and
instead the contents of the container will be used.


$_ no longer accessible from caller's scope


In future language versions of Raku, it will become impossible to access the
C<$_> variable of the caller's scope, because it will not have been marked as
a dynamic variable.  So please consider changing:


or, using the subroutine as a method syntax, with the prefix C<.> shortcut
to use that scope's C<$_> as the invocant:


Source can be located at: https://github.com/lizmat/P5ref . Comments and
Pull Requests are welcome.


Re-imagined from Perl as part of the CPAN Butterfly Plan.


This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.


P5ref

use v6.d;

unit module P5readlink:ver<0.0.9>:auth<zef:lizmat>;

proto sub readlink(|) is export {*}
multi sub readlink(--> Str:D) {
    readlink(CALLERS::<$_>)
}
multi sub readlink(Str() $path --> Str:D) {
    use nqp;  # readlink functionality only exposed as nqp ops
    nqp::stat($path,nqp::const::STAT_EXISTS) && nqp::fileislink($path)
      ?? nqp::readlink($path)
      !! Nil
}



say readlink("foobar"); # string if symlink, Nil if not


with "foobar" {
    say readlink; # string if symlink, Nil if not
}


This module tries to mimic the behaviour of Perl's C<readlink> built-in
as closely as possible in the Raku Programming Language.


readlink EXPR
readlink
        Returns the value of a symbolic link, if symbolic links are
        implemented. If not, raises an exception. If there is a system
        error, returns the undefined value and sets $! (errno). If EXPR is
        omitted, uses $_.


Portability issues: "readlink" in perlport.


Currently C<$!> is B<not> set when Nil is returned.


Source can be located at: https://github.com/lizmat/P5readlink . Comments and
Pull Requests are welcome.


P5readlink

The Raku Knowledge Base


=begin React :component<HeaderCol> :id<footer>  
=begin nested :!nested
=item1 B<Language>
    =item2 L<Get started|file:../getting-started/getting-started.podlite>
    =item2 L<Why Raku?|/doc/language/faq#Why-should-I-learn-Raku-What's-so-great-about-it>
    =item2 L<Try Raku|https://glot.io/new/raku>
    =item2 L<Raku cheat sheet|https://github.com/Raku/mu/blob/master/docs/Perl6/Cheatsheet/cheatsheet.txt>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<Raku on Exercism|https://exercism.org/tracks/raku>
    =item2 L<Wikipedia|https://en.wikipedia.org/wiki/Raku_(programming_language)>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=begin nested :!nested

=item1 B<L<Documentation|/doc>>
    =item2 L<Getting started, Migration guides from other languages, & Tutorials | file:../doc/introduction.podlite>
    =item2 L<Language References|file:../doc/reference.podlite>
    =item2 L<Type Reference| file:../doc/types.podlite>
    =item2 L<Miscellaneous| file:../doc/miscellaneous.podlite>
    =item2 L<FAQs (Frequently Asked Questions)|/doc/language/faq>
    =item2 L<Community|/doc/language/community>
    =item2 L<The list of all documents|file:../doc/index.podlite>

=item1 B<Resources>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>

=end nested
=begin nested :!nested

=item1 B<Resoures>
    =item2 L<Download | file:../download/index.podlite>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=item1 B<Learning>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Wikibook |https://en.wikibooks.org/wiki/Raku_Programming>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>
    =item2 L<Learn Raku in Y minutes|https://learnxinyminutes.com/docs/raku/>
    =item2 L<Golfing |https://github.com/AlexDaniel/raku-golf-cheatsheet>
=end nested
=begin nested :!nested

=item1 B<Explore>
    =item2 L<Raku Blog Aggregator|https://planet.raku.org/>
    =item2 L<Rakudo Weekly|https://rakudoweekly.blog/>
    =item2 L<The Weekly Challenge |https://perlweeklychallenge.org/>
    =item2 L<Raku Advent Calendar|https://raku-advent.blog/>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=end React


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README

NAME

SYNOPSIS

DESCRIPTION

ORIGINAL PERL DOCUMENTATION

PORTING CAVEATS

$! not always set

$_ no longer accessible from caller's scope

AUTHOR

COPYRIGHT AND LICENSE

P5readlink v0.0.9

Authors

License

Dependencies

Test Dependencies

Provides

Documentation