NAME
YAML::Syck - Fast, lightweight YAML loader and dumper
SYNOPSIS
use YAML::Syck;
# Set this for interoperability with other YAML/Syck bindings:
# e.g. Load('Yes') becomes 1 and Load('No') becomes ''.
$YAML::Syck::ImplicitTyping = 1;
$data = Load($yaml);
$yaml = Dump($data);
# $file can be an IO object, or a filename
$data = LoadFile($file);
DumpFile($file, $data);
# A string with multiple YAML streams in it
$yaml = Dump(@data);
@data = Load($yaml);
# Dumping into a pre-existing output buffer
my $yaml;
DumpInto(\$yaml, @data);
DESCRIPTION
This module provides a Perl interface to the libsyck data serialization
library. It exports the "Dump" and "Load" functions for converting Perl
data structures to YAML strings, and the other way around.
NOTE: If you are working with other language's YAML/Syck bindings (such
as Ruby), please set $YAML::Syck::ImplicitTyping to 1 before calling the
"Load"/"Dump" functions. The default setting is for preserving
backward-compatibility with "YAML.pm".
Differences Between YAML::Syck and YAML
Error handling
Some calls are designed to die rather than returning YAML. You should
wrap your calls in eval to assure you do not get unexpected results.
FLAGS
$YAML::Syck::Headless
Defaults to false. Setting this to a true value will make "Dump" omit
the leading "---\n" marker.
$YAML::Syck::SortKeys
Defaults to false. Setting this to a true value will make "Dump" sort
hash keys.
$YAML::Syck::SingleQuote
Defaults to false. Setting this to a true value will make "Dump" always
emit single quotes instead of bare strings.
$YAML::Syck::ImplicitTyping
Defaults to false. Setting this to a true value will make "Load"
recognize various implicit types in YAML, such as unquoted "true",
"false", as well as integers and floating-point numbers. Otherwise, only
"~" is recognized to be "undef".
$YAML::Syck::ImplicitUnicode
Defaults to false. For Perl 5.8.0 or later, setting this to a true value
will make "Load" set Unicode flag on for every string that contains
valid UTF8 sequences, and make "Dump" return a unicode string.
Regardless of this flag, Unicode strings are dumped verbatim without
escaping; byte strings with high-bit set will be dumped with backslash
escaping.
However, because YAML does not distinguish between these two kinds of
strings, so this flag will affect loading of both variants of strings.
If you want to use LoadFile or DumpFile with unicode, you are required
to open your own file in order to assure it's UTF8 encoded:
open(my $fh, ">:encoding(UTF-8)", "out.yml");
DumpFile($fh, $hashref);
$YAML::Syck::ImplicitBinary
Defaults to false. For Perl 5.8.0 or later, setting this to a true value
will make "Dump" generate Base64-encoded "!!binary" data for all
non-Unicode scalars containing high-bit bytes.
$YAML::Syck::UseCode / $YAML::Syck::LoadCode / $YAML::Syck::DumpCode
These flags control whether or not to try and eval/deparse perl source
code; each of them defaults to false.
Setting $YAML::Syck::UseCode to a true value is equivalent to setting
both $YAML::Syck::LoadCode and $YAML::Syck::DumpCode to true.
$YAML::Syck::LoadBlessed
Defaults to true. Setting to false will block YAML::Syck from doing ANY
blessing. This is an interface change since 1.21. The variable name was
misleading, implying that no blessing would happen when in fact it did.
Prior to 1.22, setting this to a false value only prevented "Load" from
blessing tag names that did not begin with "!!perl" or "!perl";.
BUGS
Dumping Glob/IO values do not work yet.
Dumping of Tied variables is unsupported.
Dumping into tied (or other magic variables) with "DumpInto" might not
work properly in all cases.
CAVEATS
This module implements the YAML 1.0 spec. To deal with data in YAML 1.1,
please use the "YAML::XS" module instead.
The current implementation bundles libsyck source code; if your system
has a site-wide shared libsyck, it will *not* be used.
Tag names such as "!!perl/hash:Foo" is blessed into the package "Foo",
but the "!hs/foo" and "!!hs/Foo" tags are blessed into "hs::Foo". Note
that this holds true even if the tag contains non-word characters; for
example, "!haskell.org/Foo" is blessed into "haskell.org::Foo". Please
use Class::Rebless to cast it into other user-defined packages. You can
also set the LoadBlessed flag false to disable all blessing.
This module has a lot of known issues
<https://rt.cpan.org/Public/Dist/Display.html?Name=YAML-Syck> and has
only been semi-actively maintained since 2007. If you encounter an issue
with it probably won't be fixed unless you offer up a patch
<http://github.com/toddr/YAML-Syck> in Git that's ready for release.
There are still good reasons to use this module, such as better
interoperability with other syck wrappers (like Ruby's), or some edge
case of YAML's syntax that it handles better. It'll probably work
perfectly for you, but if it doesn't you may want to look at YAML::XS,
or perhaps at looking another serialization format like JSON.
SEE ALSO
YAML, JSON::Syck
<http://www.yaml.org/>
AUTHORS
Audrey Tang <cpan@audreyt.org>
COPYRIGHT
Copyright 2005-2009 by Audrey Tang <cpan@audreyt.org>.
This software is released under the MIT license cited below.
The libsyck code bundled with this library is released by "why the lucky
stiff", under a BSD-style license. See the COPYING file for details.
The "MIT" License
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.