EBook::Tools(3pm)

📦

version 0.5.4 · 3 versions

0.5.4 · debian trixie, ubuntu resolute, ubuntu stonking (latest)
0.5.4 · ubuntu jammy, ubuntu noble
0.5.4 · debian bookworm

, in debian trixie, ubuntu resolute, ubuntu stonking

EBook::Tools(3pm) — User Contributed Perl Documentation 💖

okay bestie, welcome to the EBook::Tools(3pm) manual page from User Contributed Perl Documentation. Grab your iced coffee, because we're decoding this together, and no cap, it's actually iconic. ✨

✨ NAME ✨

EBook::Tools — Object class for manipulating and generating E-books 🫶

🌸 DESCRIPTION 🌸

So like, this module gives you an object interface plus a bunch of related procedures. Their whole job? Creating or modifying documents that are centered around the International Digital Publishing Forum (IDPF) standards — currently both OEBPS v1.2 and OPS/OPF v2.0. It's giving standards-compliant ebook realness. 💅

🦋 SYNOPSIS 🦋

use EBook::Tools qw(split_metadata system_tidy_xml);
$EBook::Tools::tidysafety = 2;

my $opffile = split_metadata('ebook.html');
my $otheropffile = 'alternate.opf';
my $retval = system_tidy_xml($opffile,'tidy-backup.xml');
my $ebook = EBook::Tools->new($opffile);
$ebook->fix_opf20;
$ebook->fix_misc;
$ebook->print;
$ebook->save;

$ebook->init($otheropffile);
$ebook->fix_oeb12;
$ebook->gen_epub;

🎀 DEPENDENCIES 🎀

💖 Perl Modules 💖

Archive::Zip
Data::UUID (or OSSP::UUID)
Date::Manip — note that Date::Manip will die on MS Windows system unless the TZ environment variable is set in a specific manner. See:

http://search.cpan.org/perldoc?Date::Manip#TIME_ZONES

File::MimeInfo
HTML::Parser
Lingua::EN::NameParse
Tie::IxHash
Time::Local
URI::Escape
XML::Twig

🦋 Other Programs 🦋

Tidy

The command tidy needs to be available, and ideally on the path. If it isn't on the path, package variable $tidycmd can be set to its absolute path. If tidy cannot be found, system_tidy_xml() and system_tidy_xhtml() will be nonfunctional.

💜 CONFIGURABLE PACKAGE VARIABLES 💜

%bisacsubjects — A mapping of lowercase BISAC codes and text descriptions to standard capitalized text descriptions. As BISG claims copyright on this and does not allow the lists to be redistributed, this list must be downloaded and cached locally via ebook dlbisac before it is available.

Running the unit tests will cause this to happen automatically.

%bisactolc — An extremely incomplete mapping of lowercase BISAC codes and text descriptions to Library of Congress standard subjects.
%booktypes — A hash mapping all-lowercase terms to a standard vocabulary to be used in <dc:type> elements.
%dcelements12 — A tied IxHash mapping an all-lowercase list of Dublin Core metadata element names to the capitalization dictated by the OEB 1.2 specification, used by the fix_oeb12() and fix_oeb12_dcmeta() methods. Changing the tags in this list will change the tags recognized and placed inside the <dc-metadata> element.

Order is preserved and significant — fix_oeb12 will output DC metadata elements in the same order as in this hash, though order for tags of the same name is preserved from the input file.

%dcelements20 — A tied IxHash mapping an all-lowercase list of Dublin Core metadata element names to the all-lowercase form dictated by the OPF 2.0 specification (which means it maps the all-lowercase tags to themselves). It is used by the fix_opf20() and fix_opf20_dcmeta() methods. Changing the tags in this list will change the tags recognized and placed directly under the <metadata> element.

Order is preserved and significant — fix_opf20 will output DC metadata elements in the same order as in this hash, though order for tags of the same name is preserved from the input file.

%lcsubjects — An extremely incomplete mapping of lowercase terms to Library of Congress subject classifications. This is used for automatic normalization of subject elements. Every value in the hash has a lowercase representation of itself as a key in addition to any aliases.

This MUST NOT contain mappings from BISAC codes or descriptors to Library of Congress subjects. Use %bisactolc for that.

%nonxmlentity2char — This is the %entity2char conversion map from HTML::Entities with the 5 pre-defined XML entities (amp, gt, lt, quot, apos) removed. This is used during by init() to sanitize the OPF file data before parsing. This hash can be modified to allow and convert other non-standard entities to unicode characters. See HTML::Entities for details.
%publishermap — A hash mapping known variants of publisher names to a canonical form, used by fix_publisher(), and thus also indirectly by fix_misc().

Keys should be entered in lowercase. The hash can also be set empty to prevent fix_publisher() from taking any action at all.

%referencetypes — A hash mapping valid OPF 2.0 reference types to themselves, along with common variants to standard types.
%relatorcodes — A hash mapping the MARC Relator Codes (see: http://www.loc.gov/marc/relators/relacode.html) to their descriptive names.
%sexcodes — A hash normalizing subject tags for erotic fiction, as used by StoriesOnline, ASSTR, and Literotica, among others.

Unlike the other mappings, this one is not lowercased, and the keys are case-sensitive. The hash maps only to the canonical base code, but subject normalization will also add a prefix, defaulting to the BISAC format of 'FICTION / Erotica / '.

%strangenames, %strangefileas — Hashes mapping mapping known incorrect outputs of name normalization to correct format. The first handles the main name display, the second the file-as output.
$tidycmd — The tidy executable name. This has to be a fully qualified pathname if tidy isn't on the path. Defaults to 'tidy'.
$tidyxhtmlerrors — The name of the error output file from system_tidy_xhtml(). Defaults to 'tidyxhtml-errors.txt'
$tidyxmlerrors — The name of the error output file from system_tidy_xml(). Defaults to 'tidyxml-errors.txt'
$tidysafety — The safety level to use when running tidy (default is 1). Potential values are:
- $tidysafety < 1: No checks performed, no error files kept, works like a clean tidy -m

This setting is DANGEROUS!

$tidysafety == 1: Overwrites original file if there were no errors, but even if there were warnings. Keeps a log of errors, but not warnings.
$tidysafety == 2: Overwrites original file if there were no errors, but even if there were warnings. Keeps a log of both errors and warnings.
$tidysafety == 3: Overwrites original file only if there were no errors or warnings. Keeps a log of both errors and warnings.
$tidysafety = 4>: Never overwrites original file. Keeps a log of both errors and warnings.

%validspecs — A hash mapping valid specification strings to themselves, primarily used to undefine unrecognized values. Default valid values are 'OEB12' and 'OPF20'.

🎀 CONSTRUCTORS AND INITIALIZATION 🎀

`new($filename)`

Instantiates a new EBook::Tools object. If $filename is specified, it will also immediately initialize itself via the init method.

`init($filename)`

Initializes the object from an existing OPF file. If $filename is specified and exists, the OEB object will be set to read and write to that file before attempting to initialize. Otherwise, if the object currently points to an OPF file it will use that name. If there is no OPF filename data, and $filename was not specified, it will make a last-ditch attempt to find an OPF file first by looking in META-INF/container.xml, and if nothing is found there, by looking in the current directory for a single OPF file.

If no such files are found (or more than one is found), the initialization croaks.

`init_blank(%args)`

Initializes an object containing nothing more than the basic OPF framework, suitable for adding new documents when creating an e-book from scratch.

Arguments

init_blank takes up to three optional named arguments:

opffile — This specifies the OPF filename to use. If not specified, defaults to 'content.opf'
author — This specifies the content of the initial dc:creator element. If not specified, defaults to "Unknown Author".
title — This specifies the content of the initial dc:title element. If not specified, defaults to "Unknown Title".

Example

        init_blank('opffile' => 'newfile.opf',
                   'title' => 'The Great Unknown');

🌈 ACCESSOR METHODS 🌈

The following methods return data deeper in the structure than the auto-accessors, but still do not modify any object data or files.

`adult()`

Returns the text of the Mobipocket-specific <Adult> element, if it exists. Expected values are 'yes' and undef.

`contributor_list()`

Returns a list containing the text of all dc:contributor elements (case-insensitive) or undef if none are found.

In scalar context, returns the first contributor, not the last.

`coverimage()`

Returns the href to the cover image, or undef if none is found.

Checks the following in order:

<reference type="other.ms-coverimage-standard">
<EmbeddedCover>
<meta name="cover"> (as href)
<meta name="cover"> (as item id)

`date_list(%args)`

Returns the text of all dc:date elements (case-insensitive) matching the specified attributes.

In scalar context, returns the first match, not the last.

Returns undef if no matches are found.

Arguments

"id" — 'id' attribute that must be matched exactly for the result to be added to the list
"event" — 'opf:event' or 'event' attribute that must be matched exactly for the result to be added to the list

If both arguments are specified a value is added to the list if it matches either one (i.e. the logic is OR).

`description()`

Returns the description of the e-book, if set, or undef otherwise.

`element_list(%args)`

Returns a list containing the text values of all elements matching the specified criteria.

Arguments

"cond" — The XML::Twig search condition used to find the elements. Typically this is just the GI (tag) of the element you wish to find, but it can also be a qr// expression, coderef, or anything else that XML::Twig can work with. See the XML::Twig documentation for details.

If this is not specified, an error is added and the method returns undef.

"id" (optional) — 'id' attribute that must be matched exactly for the result to be added to the list
"scheme" (optional) — 'opf:scheme' or 'scheme' attribute that must be matched exactly for the result to be added to the list
"event" (optional) — 'opf:event' or 'event' attribute that must be matched exactly for the result to be added to the list

okay bestie, one more thing about that OR logic, and then we move on for real: if more than one of the arguments id, scheme, or event are specified, a value gets added to the list if it matches any one of them (i.e. the logic is OR). one match is literally all it takes 💅

`errors()`

hands you back an arrayref stuffed with every error message that's been generated. that's it, that's the whole vibe. 🫶

`identifier()`

gives you the text of the dc:identifier element that the 'unique-identifier' attribute of the root 'package' element is pointing at. if she can't locate it at all? undef, crying, no notes. 😭

`isbn_list(%args)`

returns a list of every single ISBN that matches the attributes you asked for. for the full deets on how the ISBN elements actually get found, go read twigelt_is_isbn() — she explains it properly. 💖

returns undef if nothing matches. nada. zero. 🌵

⚠️ in scalar context she hands you the first match, not the last. do not get got by that.

`isbns(%args)`

returns all of the ISBN identifiers matching the specified attributes, as a list of hashrefs — one hash per ISBN identifier, in the order they were found. the hash keys are:

'id' — holds the value of the 'id' attribute ✨
'scheme' — holds the value of either the 'opf:scheme' or 'scheme' attribute, whichever one is found first
'isbn' — holds the text of the element 📖

if nothing turns up, returns undef.

⚠️ in scalar context returns the first match, not the last. same rule as her sister method, iykyk.

`languages()`

returns a list with the text of all the dc:language entries (case-insensitive), or undef if there are none. 🌈

in scalar context she returns the first match, not the last.

`manifest(%args)`

returns every item in the manifest as a list of hashrefs — one hash per manifest item, in the order they appear. the hash keys are 'id', 'href', and 'media-type', each one handing back the appropriate attribute, if there is one. 🎀

in scalar context, returns the first match, not the last.

Arguments

manifest() takes four optional named arguments:

id — 'id' attribute to match
href — 'href' attribute to match
mtype — 'media-type' attribute to match
logic — logic to use (valid values are 'and' or 'or', default: 'and')

If any of the named arguments are specified, manifest() will return only the items matching the specified criteria. this is an exact, case-sensitive match — but it can still return multiple elements (especially in the case of mtype). yes, even then. 🙈

Return values

returns undef if there's no <manifest> element directly underneath <package>, or if <manifest> contains no items.

See also

manifest_hrefs(), spine()

Example

 @manifest = $ebook->manifest(id => 'ncx',
                              mtype => 'text/xml',
                              logic => 'or');

`manifest_hrefs()`

returns a list of all of the hrefs in the current OPF manifest, or the empty list if none are found.

in scalar context returns the first href, not the last.

See also: manifest(), spine_idrefs()

`opf_namespace()`

okay so some OPF generators go out of their way to explicitly assign 'opf:' as a prefix on OPF elements in the gi. which makes later parsing more complicated — and it's completely unnecessary anyway. so it gets stripped before any parsing happens. bye bestie 💅

`opfdir()`

returns the full filesystem path to the directory where the OPF metadata file will be stored. or undef if either the top-level directory or the OPF subdirectory isn't found. 🫠

`opffile()`

returns the name of the file where the OPF metadata will be stored, or undef if no value is found. (yes, the double period in the original is iconic and stays.)

`opfpath()`

returns the full filesystem path to the file where the OPF metadata will be stored, or undef if either the top level directory or the OPF filename isn't found.

`primary_author()`

finds the primary author of the book, which is defined as the first 'dc:creator' entry (case-insensitive) where either the attribute opf:role="aut" or role="aut", or the first 'dc:creator' entry if no entries with either attribute can be found. and heads up: entries must actually have text to even be considered. no text, no author, no service. 😤

in list context, returns a two-item list. item one is the text of the entry (the author name), and item two is the value of the 'opf:file-as' or 'file-as' attribute (where 'opf:file-as' gets precedence if both are present).
in scalar context, returns the text of the entry (the author name).

if no entries are found, returns undef.

uses twigelt_is_author() in the first half of the search. 🕵️

Example

 my ($fileas, $author) = $ebook->primary_author;
 my $author = $ebook->primary_author;

`print_errors()`

prints the current list of errors to STDERR. loudly, as she should. 📢

`print_warnings()`

prints the current list of warnings to STDERR. 🔔

`print_opf()`

prints the OPF file to the default filehandle.

`publishers()`

returns a list containing the text of all dc:publisher entries (case-insensitive), or undef if none are found.

in scalar context returns the first match, not the last.

`retailprice()`

returns a two-scalar list: the first scalar is the text of the Mobipocket-specific <SRP> element, if it exists, and the second is the 'Currency' attribute of that element, if it exists. 💸

in scalar context, returns just the text (the price).

returns undef if the SRP element is not found.

`review()`

returns the text of the Mobipocket-specific <Review> element, if it exists. returns undef if one isn't found.

`rights('id' => 'identifier')`

returns a list containing the text of all dc:rights or dc:copyrights entries (case-insensitive) in the e-book, or undef if none are found.

in scalar context returns the first match, not the last.

if the optional named argument 'id' is specified, she'll only return entries where the id attribute matches the specified identifier. and even though it still returns a list, if more than one entry is found, a warning gets logged. 👀

💀 note that dc:copyrights is not a valid Dublin Core element — it's included only because some broken Mobipocket books use it. we don't make the rules, we just accommodate the chaos.

`search_knownuids()`

searches the OPF twig for the first dc:identifier (case-insensitive) element with an ID matching known UID IDs.

returns the ID if a match is found, undef otherwise. ⭐

`search_knownuidschemes()`

searches descendants of the OPF twig element for the first <dc:identifier> or <dc:Identifier> subelement with the attribute 'scheme' or 'opf:scheme' matching a known list of schemes for unique IDs.

🚨 NOTE: this is NOT a case-insensitive search! if you have to deal with really bizarre input, make sure you run fix_oeb12() or fix_opf20() before calling fix_packageid() or fix_misc(). seriously, bestie.

returns the ID if a match is found, undef otherwise.

`spec()`

returns the version of the OEB specification currently in use. valid values are "OEB12" and "OPF20". this value will default to undef until fix_oeb12 or fix_opf20 is called — because there's genuinely no way for the object to know what specification is being conformed to (if any) until it actually attempts to enforce it. ✨

`spine()`

returns all of the manifest items referenced in the spine as a list of hashrefs — one hash per manifest item, in the order they appear. the hash keys are 'id', 'href', and 'media-type', each returning the appropriate attribute, if any. 🦋

in scalar context, returns the first item, not the last.

returns undef if there's no <spine> element directly underneath <package>, or if <spine> contains no itemrefs. and if <spine> exists but <manifest> doesn't — or a spine itemref exists but points at an ID that isn't in the manifest — then spine() logs an error and returns undef. 😭

See also: spine_idrefs(), manifest()

`spine_idrefs()`

returns a list of all of the idrefs in the current OPF spine, or the empty list if none are found.

in scalar context, returns the first idref, not the last.

`subject_list()`

returns a list containing the text of all dc:subject elements, or undef if none are found. 📚

in scalar context, returns the first subject, not the last.

`title()`

returns the title of the e-book, or undef if no dc:title element (case-insensitive) exists. and if a dc:title element does exist but contains no text, she returns an empty string. subtle difference, big consequences. 👑

`twig()`

returns the raw XML::Twig object used to store the OPF metadata.

🙈 okay so like — this twig can be manipulated via the standard XML::Twig methods, but doing that requires caution and is not recommended. in particular, changing the root element from here will cause the EBook::Tools internal twig and twigroot attributes to become unlinked, and the result of any subsequent action is not defined. not "probably fine." not "probably weird." undefined. periodt.

`twigcheck()`

croaks showing the calling location unless $self has both a twig and a twigroot, and the twigroot is <package>. used as a sanity check for methods that use twig or twigroot. 🚔

`twigroot()`

returns the raw XML::Twig root element used to store the OPF metadata.

💀 this twig element can be manipulated via the standard XML::Twig::Elt methods, but be careful not to attempt to cut this element from its twig — doing so will cause the EBook::Tools internal twig and twigroot attributes to become unlinked, and the result of any subsequent action is not defined. she warned you, bestie.

`warnings()`

returns an arrayref containing any generated warning messages. 🫶

🛠️ MODIFIER METHODS 🛠️

unless otherwise specified, all modifier methods return undef if an error was added to the error list, and true otherwise — even if a warning was added to the warning list. warnings don't kill the vibe, errors do. 💅

`add_document($href,$id,$mediatype)`

adds a document to the OPF manifest and the spine, creating <manifest> and <spine> if they're needed. if you only want to add an item to the OPF manifest, see add_item() instead, bestie. ✨

Arguments

$href — the href to the document in question. usually this is just a filename (or a relative path and filename) of a file in the current working directory. and listen: if you're planning to eventually generate a .epub book, all hrefs MUST be in or below the current working directory. no sneaking upstairs. 🚫

the method returns undef if $href is not defined or empty.

$id — the XML ID to use. if not specified, it defaults to the href with invalid characters removed. 🎀

`$id` 💅

This one's gotta be unique — not just inside the manifest list, okay, but across every single element in the OPF file. If a duplicate ID is out there lurking, the method sets an error and returns undef. No cap. 🫶

`$mediatype` (optional)

The mime type of the document. If you don't say, it'll try to autodetect the mime type, and if that flops, it defaults to 'application/xhtml+xml'. So chill, it's got a fallback. ✨

`add_error(@errors)` 😭

Adds @errors to the list of object errors. Each member of @errors should be a string containing the entire text of the error, with no ending newline. Bestie, we keep it tidy around here.

SEE ALSO: add_warning(), clear_errors(), clear_warnerr()

`add_identifier(%args)` 🎀

Creates a new dc:identifier element containing the specified text, id, and scheme.

If a <dc-metadata> element exists underneath <metadata>, the identifier element will be created underneath the <dc-metadata> in OEB 1.2 format — otherwise the title element is created underneath <metadata> in OPF 2.0 format. It read the room and picked. 💅

Returns the twig element containing the new identifier. Iconic.

Arguments

add_identifier() takes three named arguments, one mandatory, two optional. The classic ratio.

"text" — the text of the identifier. This is mandatory, and the method croaks if it is not present. 🩸
"scheme" — 'opf:scheme' or 'scheme' attribute to be added (optional)
"id" — 'id' attribute to be added. If this is specified, and the id is already in use, a warning will be added but the method will continue, removing the id attribute from the element that previously contained it. It yanks it, respectfully. 🙈

`add_item($href,$id,$mediatype)` 🦋

Adds a document to the OPF manifest (but not spine), creating <manifest> if necessary. If you wanna add an item to both the OPF manifest and spine, go look at add_document() instead, babe.

Arguments

`$href`

The href to the document in question. Usually, this is just a filename (or relative path and filename) of a file in the current working directory. If you are planning to eventually generate a .epub book, all hrefs MUST be in or below the current working directory. MUST. Periodt.

`$id`

The XML ID to use. If not specified, defaults to the href with all nonword characters removed. Glow-down. ✨

This must be unique not only to the manifest list, but to every element in the OPF file. If a duplicate ID exists, the method sets an error and returns undef.

`$mediatype` (optional)

The mime type of the document. If not specified, will attempt to autodetect the mime type, and if that fails, will set an error and return undef. (Yeah, this one's strict — no secret default here, unlike our other friend. 💀)

`add_metadata(%args)` 🌸

Creates a metadata element with the specified text, attributes, and parent.

If a <dc-metadata> element exists underneath <metadata>, the language element will be created underneath the <dc-metadata> and any standard attributes will be created in OEB 1.2 format — otherwise the element is created underneath <metadata> in OPF 2.0 format.

Returns 1 on success, returns undef if no gi or if no text was specified.

Arguments

`"gi"`

The generic identifier (tag) of the metadata element to alter or create. If not specified, the method sets an error and returns undef. No gi, no glory. 😭

`"parent"`

The generic identifier (tag) of the parent to use for any newly created element. If not specified, defaults to 'dc-metadata' if 'dc-metadata' exists underneath 'metadata', and 'metadata' otherwise.

A newly created element will be created under the first element found with this gi. A modified element will be moved under the first element found with this gi.

Newly created elements will use OPF 2.0 attribute names if the parent is 'metadata' and OEB 1.2 attribute names otherwise.

`"text"`

This specifies the element text to set. If not specified, the method sets an error and returns undef.

`"id"` (optional)

This specifies the ID to set on the element. If set and the ID is already in use, a warning is logged and the ID is removed from the other location and assigned to the element. Stealing it, but making it official. 💅

`"fileas"` (optional)

This specifies the file-as attribute to set on the element.

`"role"` (optional)

This specifies the role attribute to set on the element.

`"scheme"` (optional)

This specifies the scheme attribute to set on the element.

Example

 $retval = $ebook->add_metadata(gi => 'AuthorNonstandard',
                                text => 'Element Text',
                                id => 'customid',
                                fileas => 'Text, Element',
                                role => 'xxx',
                                scheme => 'code');

`add_subject(%args)` 🍓

Creates a new dc:subject element containing the specified text, code, and id.

If a <dc-metadata> element exists underneath <metadata>, the subject element will be created underneath the <dc-metadata> in OEB 1.2 format — otherwise the title element is created underneath <metadata> in OPF 2.0 format.

Returns the twig element containing the new subject. She's here and she's serving. ✨

Arguments

add_subject() takes four named arguments, one mandatory, three optional.

"text" — the text of the subject. This is mandatory, and the method croaks if it is not present. 🩸
"scheme" (optional) — 'opf:scheme' or 'scheme' attribute to be added. Be warned that neither the OEB 1.2 nor the OPF 2.0 specifications allow a scheme to be added to this element, so if this is specified, the resulting OPF file will fail to validate against either standard. So like… your choice bestie but the validator is gonna be mad.
"basiccode" (optional) — 'BASICCode' attribute to be added. Be warned that this is a Mobipocket-specific attribute that does not exist in either the OEB 1.2 nor the OPF 2.0 specifications, so if this is specified, the resulting OPF file will fail to validate against either standard. Mobipocket-only vibes. 🫠
"id" (optional) — 'id' attribute to be added. If this is specified, and the id is already in use, a warning will be added but the method will continue, removing the id attribute from the element that previously contained it.

`add_warning(@newwarning)` 🙈

Joins @newwarning to a single string and adds it to the list of object warnings. The warning should not end with a newline newline. (Yes it really says that. We're just reporting the lore. 😭)

SEE ALSO: add_error(), clear_warnings(), clear_warnerr()

`clear_errors()` 🧚

Clear the current list of errors. Fresh start, bestie.

`clear_warnerr()` 🌈

Clear both the error and warning lists. Total reset, main character energy.

`clear_warnings()` ⭐

Clear the current list of warnings.

`delete_meta_filepos()` 💀

Deletes metadata elements with the attribute 'filepos' underneath the given parent element.

These are secondary metadata elements included in the output from mobi2html may that are not used. (That's the original's phrasing, we're not touching it. 🙏) Basically: leftovers, get them out.

`delete_subject(%args)` 🎀

Deletes dc:subject and dc:Subject elements based on text content or the id, scheme, or basiccode attributes. Matches are case-sensitive.

Specifying multiple arguments will delete subject matching any of them.

This has the same potential arguments as add_subject.

Returns the count of elements deleted. Numbers, bestie. 📊

`fix_creators()` 👑

Normalizes creator and contributor names and file-as attributes.

Names are normalized to 'First Last' format, while file-as attributes are normalized to 'Last, First' format.

This can damage some unusual names that do not match standard capitalization formats, so it is not made part of fix_misc(). So it's not in the auto-mix, and honestly? That's on purpose. 🙈

`fix_dates()` 🦋

Standardizes all <dc:date> elements via fix_datestring(). Adds a warning to the object for each date that could not be fixed.

Called from fix_misc().

`fix_guide()` 🔥

Fixes problems related to the OPF guide elements, specifically:

Ensures the guide element exists
Moves all reference elements directly underneath the guide element
Finds nonstandard reference types and either converts them to standard or prefaces them with 'other.'
Finds reference elements with a href with only an anchor portion and assigns them to the first spine href. This only works if the spine is in working condition, so it may be wise to run fix_spine() before fix_guide() if the input is expected to be very badly broken.

Logs a warning if a reference href is found that does not appear in the manifest.

`fix_languages(%args)` 🌸

Checks through the <dc:language> elements (case-insensitive) and removes any duplicates. If no <dc:language> elements are found, one is created.

TODO: Also convert language names to IANA language and region codes.

Arguments

"default" — The default language string to use when creating a new language element. If not specified, defaults to 'en'. 🇬🇧✨

`fix_links()` 🫶

Checks through the links in the manifest and checks them for anything they might link to, adding anything missing to the manifest.

A warning is added for every manifest item missing a href.

If no <manifest> element exists directly underneath the <package> root, or <manifest> contains no items, the method logs a warning and returns undef. Otherwise, it returns 1.

`fix_manifest()` 💜

Finds all <item> elements and moves them underneath <manifest>, creating <manifest> if necessary.

Logs a warning but continues if it finds an <item> with a missing id or href attribute. If both id and href attributes are missing, logs a warning, skips moving the item entirely (unless it was already underneath <manifest>, in which case it is moved to preserve its sort order along all other items under <manifest>), but otherwise continues.

`fix_metastructure_basic()` 🌟

Verifies that <metadata> exists (creating it if necessary), and moves it to be the first child of <package>. If additional <metadata> elements exist, their children are moved into the first one found and then the extras are deleted.

Used in fix_metastructure_oeb12(), fix_packageid(), and set_primary_author(%args).

`fix_metastructure_oeb12()` 🧚

Verifies the existence of <metadata>, <dc-metadata>, and <x-metadata>, creating them as needed, and making sure that <metadata> is a child of <package>, while <dc-metadata> and <x-metadata> are children of <metadata>.

Used in fix_oeb12() and fix_mobi().

`fix_misc()` ✨

Fixes miscellaneous potential problems in OPF data. Specifically, this is a shortcut to calling delete_meta_filepos(), fix_packageid(), fix_dates(), fix_languages(), fix_publisher(), fix_manifest(), fix_spine(), fix_subjects(), fix_type(), fix_guide(), and fix_links(). She contains multitudes.

fix_creators() is not run from this, as it carries a risk of taking a correct name and making it incorrect. Not me being careful with people's names. 🙈

The objective here is that you can run either fix_misc() and either fix_oeb12() or fix_opf20() and a perfectly valid OPF file will result from only two calls. Two calls, bestie. That's it. Slay. 💅

`fix_mobi()` 🌈

Manipulates the twig to fix Mobipocket-specific issues.

Force the OEB 1.2 structure (lowkey no chill about it, but not the namespace, DTD, or capitalization) so that <dc-metadata> and <x-metadata> are guaranteed to exist. Manifesting, fr.
Find and move all Mobi-specific elements to <x-metadata> — like, scoot, bestie, that's your room now 🚪
If no <output> element exists, one gets created for a utf-8 ebook ✨

Heads up tho: forcibly creating <output> will make the OPF file become noncompliant with IDPF specifications. Not a vibe if you care about that. 💀

fix_oeb12()

Modifies the OPF data so it conforms to the OEB 1.2 standard. Specifically, bestie, the glow-up involves:

adding the OEB 1.2 doctype
removing OPF 2.0 version and namespace attributes
setting the OEB 1.2 namespace on <package>
moving all of the dc-metadata elements underneath an element with tag <dc-metadata>, which itself is forced to be underneath <metadata>, which is created if it doesn't exist
moving any remaining tags underneath <x-metadata>, again forced to be under <metadata>
making the dc-metadata tags conform to the OEB v1.2 capitalization

fix_oeb12_dcmetatags()

Does a case-insensitive search for tags matching a known list of DC metadata elements and corrects the capitalization to the OEB 1.2 standard. Also corrects 'dc:Copyrights' to 'dc:Rights'. See the global variable $dcelements12.

The "fix_oeb12()" method does this also, but fix_oeb12_dcmetatags() is usable separately for the case where you want DC metadata elements with consistent tag names, but don't want them moved from wherever they are. Pick your fighter. 💅

fix_opf20()

Modifies the OPF data so it conforms to the OPF 2.0 standard. The whole ritual, bestie:

moving all of the dc-metadata and x-metadata elements directly underneath <metadata>
removing the <dc-metadata> and <x-metadata> elements themselves
lowercasing the dc-metadata tags (and fixing dc:copyrights to dc:rights)
setting namespaces on dc-metata OPF attributes
setting version and xmlns attributes on <package>
setting xmlns:dc and xmlns:opf on <metadata>

fix_opf20_dcmetatags()

Makes a case-insensitive search for tags matching a known list of DC metadata elements and corrects the capitalization to the OPF 2.0 standard. Also corrects 'dc:copyrights' to 'dc:rights'. See the package variable %dcelements20.

The "fix_opf20()" method does this also, but fix_opf20_dcmetatags() is usable separately for the case where you want DC metadata elements with consistent tag names, but don't want them moved from wherever they are. Same energy as its OEB 1.2 twin, no cap. 🫶

fix_packageid()

Checks the <package> element for the attribute unique-identifier, makes sure it's mapped to a valid dc:identifier subelement, and if not, searches those subelements for an identifier to assign, or creates one if nothing can be found. It's giving project manager energy ✨

Requires that <metadata> exist. Croaks if it doesn't. 😭 Run "fix_oeb12()" or "fix_opf20()" before calling this if the input might be very broken — like, heal it first, then do the thing.

fix_publisher()

Standardizes publisher names in all dc:publisher entities, mapping known variants of a publisher's name to a canonical form via package variable %publishermap.

Publisher entries with no text are deleted. Gone. Not invited to the party anymore. 🙈

fix_spine()

Fixes problems with the OPF spine 🦴 specifically:

Moves all <itemref> elements underneath <spine>, creating <spine> if necessary.

fix_subjects()

Deletes empty and duplicate subject elements and normalizes existing subject text against the known Library of Congress mappings.

If $self->{erotic} is true, then the book will be treated as a work of erotic fiction and the subjects will go through preprocessing against the %sexcodes package variable, normalizing matches and prepending 'FICTION / Erotica / ' (with a trailing space). Yes, the space matters, don't skip it. 🍓

This method is called as a component of fix_misc().

fix_type()

Normalizes <dc:type> elements against a limited list based on book types listed in Wikipedia. Lowkey it's just a vibe check with citations. 📚

gen_epub(%args)

Creates a .epub format e-book!! 🎀 This will create (or overwrite) the files 'mimetype' and 'META-INF/container.xml' in the current directory, creating the subdirectory META-INF as needed.

A NCX file will also be created if missing.

Arguments

This method can take two optional named arguments.

"filename" — the filename of the .epub output file. If not specified, takes the base name of the opf file and adds a .epub extension.
"dir" — the directory to output the .epub file. If not specified, uses the current working directory. If a specified directory does not exist, it will be created, or the method will croak. (Bestie, either it makes the folder or it screams. There is no in-between. 😭)

Example

 gen_epub(filename => 'mybook.epub',
          dir => '../epub_books');

gen_epub_files()

Generates the "mimetype" and "META-INF/container.xml" files expected by a .epub container, but does not actually generate the .epub file itself. This will be called automatically by "gen_epub". It's the backstage crew, the actual star 👑

The OPF will be normalized to the OPF 2.0 format.

If no NCX element exists, it will also be created.

gen_ncx($filename)

Creates a NCX-format table of contents from the package unique-identifier, the dc:title, dc:creator, and spine elements, and then adds the NCX entry to the manifest if it's not already referenced.

Adds an error and fails if any of those cannot be found. The first available dc:title is taken, but will prioritize dc:creator elements with opf:role="aut" over those with no role attribute (see twigelt_is_author() for details). Giving the actual authors the main character treatment, as they deserve 💅

WARNING: This method REQUIRES that the e-book be in OPF 2.0 format to function correctly. Call fix_opf20() before calling gen_ncx(). gen_ncx() will log an error and fail if $self{spec} is not set to OPF20. Not optional, not negotiable, periodt. 💀

Arguments

$filename : The filename to save to. If not specified, will use 'toc.ncx'.

This method will overwrite any existing file. (Rude but honest. 🫶)

Returns a twig containing the NCX XML, or undef on failure.

save()

Saves the OPF file to disk. Existing files are backed up to filename.backup. Safety first, bestie, we love a backup 🎀

set_adult($bool)

Sets the Mobipocket-specific <Adult> element, creating or deleting it as necessary. If $bool is true, the text is set to 'yes'. If it is defined but false, any existing elements are deleted. If it is undefined, the method immediately returns. Yeah it just leaves. ✌️

If a new element has to be created, "fix_metastructure_oeb12" is called to ensure that <x-metadata> exists and the element is created under <x-metadata>, as Mobipocket elements are not recognized by Mobipocket's software when placed directly under <metadata>. So like, placement matters, iykyk. 📍

set_cover(%args)

Sets a cover image 📸✨

In OPF 2.0, this is done by setting both a <meta name="cover"> element and a guide <reference type="other.ms-coverimage-standard"> element (though some readers will also extract the first image found in the HTML of the <reference type="cover"> element, which this method will not handle). Not our problem, not our job. 🙈

In OEB 1.2, this is done by setting the <EmbeddedCover> tag.

If the filename is not currently listed as an item in the manifest, it is added.

Arguments

"href" — the filename of the image file to use. This is mandatory. No href, no cover, no exceptions.
"id" — the id attribute to assign to its item element
"spec" — the specification to use, either OEB12 or OPF20. If this is left undefined, the current spec state will be checked, and if that is undefined, it will default to OPF20.

set_date(%args)

Sets the date metadata for a given event. If more than one dc:date or dc:Date element is present with the specified event attribute, sets the first. If no dc:date element is present with the specified event attribute, a new element is created. First come, first served, bestie. ⏰

If a <dc-metadata> element exists underneath <metadata>, the date element will be created underneath the <dc-metadata> in OEB 1.2 format, otherwise the title element is created underneath <metadata> in OPF 2.0 format.

Returns 1 on success, logs an error and returns undef if no text or event was specified.

Arguments

"text" — this specifies the description to use as the text of the element. If not specified, the method sets an error and returns undef.
"event" — this optionally specifies the event attribute for the date. This attribute is not valid in OPF 3.0 (which only allows publication date in this element) and should no longer be used. Deprecated, babes, retire it. 🪦
"id" (optional) — this specifies the ID to set on the element. If set and the ID is already in use, a warning is logged and the ID is removed from the other location and assigned to the element. Snatching IDs from other elements, we love a dramatic entrance. 💅

set_description(%args)

Sets the text and optionally ID of the first dc:description element found (case-insensitive). Creates the element if one did not exist. If a <dc-metadata> element exists underneath <metadata>, the description element will be created underneath the <dc-metadata> in OEB 1.2 format, otherwise the title element is created underneath <metadata> in OPF 2.0 format.

Returns 1 on success, returns undef if no publisher was specified. (Yeah, the doc says publisher here, we don't make the rules. 💀)

Arguments

set_description() takes one required and one optional named argument

"text" — this specifies the description to use as the text of the element. If not specified, the method returns undef.
"id" (optional) — this specifies the ID to set on the element. If set and the ID is already in use, a warning is logged and the ID is removed from the other location and assigned to the element.

Example

 $retval = $ebook->set_description('text' => 'A really good book',
                                   'id' => 'mydescid');

set_erotic($bool)

If $bool is true, "$self-"{erotic}> is set to 1, otherwise this is set to 0.

This will enable or disable special handling for erotic books, most notably in subject normalization. 🌶️

This is not related in any way to "set_adult" which is a Mobipocket-specific flag. Two completely different things, do not mix them up bestie, please. 🙏

Returns 1 if no argument is given, 0 otherwise.

set_language(%args)

Sets the text and optionally the ID of the first dc:language element found (case-insensitive). Creates the element if one did not exist. If a <dc-metadata> element exists underneath <metadata>, the language element will be created underneath the <dc-metadata> in OEB 1.2 format, otherwise the title element is created underneath <metadata> in OPF 2.0 format.

Returns 1 on success, returns undef if no text was specified.

Arguments

"text" — this specifies the language set as the text of the element. If not specified, the method sets an error and returns undef. This should be an IANA language code, and it will be lowercased before it is set. lowercase gang rise up 👑
"id" (optional) — this specifies the ID to set on the element. If set and the ID is already in use, a warning is logged and the ID is removed from the other location and assigned to the element.

Example

        $retval = $ebook->set_language('text' => 'en-us',
                                       'id' => 'langid');

...and that's the whole set_language example, slayed. 💅 Now let's keep it moving, because there are so many more setters to meet. 🫶

✨ `set_meta(%args)` ✨

Okay bestie, this one drops a <meta> element into the <metadata> area. 📥 Literally just that.

🌸 Arguments 🌸

name — the name attribute you use when finding or creating OPF 2.0 <meta> elements. You gotta pass either this or the property attribute (below), but passing both? That's an error, no cap. 😤
content — the value of the content attribute to set on OPF 2.0 elements. If this value is empty or undefined, but name is provided and matches an existing element, that element gets deleted. Bye. 👋
property — the property attribute to use when finding or creating OPF 3.0 <meta> elements. Either this or name (above) must be specified, but specifying both is an error.
refines — the refines attribute to use when finding or creating OPF 3.0 <meta> elements.
scheme — the scheme attribute to use when creating or updating OPF 3.0 <meta> elements.
text — the text set on OPF 3.0 <meta> elements. If this value is empty or undefined, but property is provided and the combination of property and refines matches an existing element, that element will be deleted. 🗑️
lang — the xml:lang attribute to set. This one's valid on both OPF 2 and OPF 3 <meta> elements. Versatile icon. 👑

✨ `set_metadata(%args)` ✨

Sets the text and, if you want, the ID of the first element of the type you specify that it finds (case-insensitive, she doesn't care about your casing 💅). And if that element didn't exist? She creates it — with the exact capitalization you specified. Periodt.

So here's the tea on where it lands: if a <dc-metadata> element exists underneath <metadata>, the language element gets created underneath the <dc-metadata>, and any standard attributes get created in OEB 1.2 format. Otherwise the element gets created underneath <metadata> in OPF 2.0 format.

Returns 1 on success. Returns undef if there's no gi, or if no text was specified. 😭

🌸 Arguments 🌸

gi — the generic identifier (tag) of the metadata element to alter or create. If you don't specify it, the method sets an error and returns undef. Rude but fair.
parent — the generic identifier (tag) of the parent to use for any newly created element. If you don't specify it, it defaults to 'dc-metadata' if 'dc-metadata' exists underneath 'metadata', and 'metadata' otherwise.
- A newly created element gets created under the first element found with this gi. A modified element gets moved under the first element found with this gi. 🚚
- Newly created elements use OPF 2.0 attribute names if the parent is 'metadata', and OEB 1.2 attribute names otherwise.
text — the element text to set. If you don't specify it, the method sets an error and returns undef.
id (optional) — the ID to set on the element. If you set it and that ID is already in use, a warning gets logged, the ID gets removed from the other location, and it gets assigned to this element. Snatched. 😌
fileas (optional) — the file-as attribute to set on the element.
role (optional) — the role attribute to set on the element.
scheme (optional) — the scheme attribute to set on the element.

🦋 Example 🦋

 $retval = $ebook->set_metadata(gi => 'AuthorNonstandard',
                                text => 'Element Text',
                                id => 'customid',
                                fileas => 'Text, Element',
                                role => 'xxx',
                                scheme => 'code');

✨ `set_opffile($filename)` ✨

Sets the filename used to store the OPF metadata. 📁

Returns 1 on success. If no filename was specified, it sets an error message and returns undef.

✨ `set_retailprice(%args)` ✨

Sets the Mobipocket-specific <SRP> element (that's Suggested Retail Price, bestie 💸), creating or deleting it as necessary.

If a new element has to be created, fix_metastructure_oeb12 gets called to make sure <x-metadata> exists, and the element gets created under <x-metadata> — because Mobipocket elements are not recognized by Mobipocket's software when placed directly under <metadata>. Ik, ik, deeply unserious of them, but that's the rule. 🤷‍♀️

🌸 Arguments 🌸

text — the price to set as the text of the element. If this is undefined, the method sets an error and returns undef. If it's set but false, any existing <SRP> element gets deleted.
currency (optional) — the value to set on the 'Currency' attribute. If you don't provide it, it defaults to 'USD' (US Dollars). 💵

✨ `set_primary_author(%args)` ✨

Sets the text, id, file-as, and role attributes of the primary author element (peep primary_author() for the deets on how she finds it) — or, if no primary author exists, she creates a brand-new element holding all that info. ✨

This method calls fix_metastructure_basic() to enforce that the <metadata> element is present. When creating a new element, it uses the OEB 1.2 element name and creates the element underneath <dc-metadata> if an existing <dc-metadata> element is found underneath <metadata>. If no existing <dc-metadata> is found, the new element gets created with the OPF 2.0 element name directly underneath <metadata>. Either way, it's probably a good idea to call fix_oeb12() or fix_opf20() after calling this method, so everything stays a consistent scheme. 🧼

🌸 Arguments 🌸

Three optional named arguments can be passed:

text — the author text to set. If omitted and a primary author element exists, the text is left as is. If omitted and no primary author element can be found, an error message gets generated and the method returns undef. 😬
fileas — the 'file-as' attribute to set. If omitted and a primary author element exists, any existing attribute is left untouched. If omitted and no primary author element can be found, the newly created element just won't have this attribute.
id — the 'id' attribute to set. If you specify it and that id is already in use, a warning gets added but the method keeps going, removing the id attribute from the element that previously had it. If omitted and a primary author element exists, any existing id is left untouched. If omitted and no primary author element can be found, the newly created element won't have an id set.
- If you call this method with no arguments at all, the only thing it does is enforce that either an 'opf:role' or 'role' attribute is set to 'aut' on the primary author element. That's it, that's the whole vibe check. ✅

🦋 Return values 🦋

Returns 1 if successful. Returns undef and sets an error message if the author argument is missing and no primary author element was found.

✨ `set_publisher(%args)` ✨

Sets the text and optionally the ID of the first dc:publisher element found (case-insensitive). Creates the element if one didn't exist. If a <dc-metadata> element exists underneath <metadata>, the publisher element gets created underneath the <dc-metadata> in OEB 1.2 format. Otherwise the title element gets created underneath <metadata> in OPF 2.0 format.

Returns 1 on success. Returns undef if no publisher was specified.

🌸 Arguments 🌸

set_publisher() takes one required and one optional named argument:

text — the publisher name to set as the text of the element. If not specified, the method returns undef.
id (optional) — the ID to set on the element. If set and the ID is already in use, a warning is logged, the ID is removed from the other location, and it's assigned to this element. Stolen, respectfully. 💅

🦋 Example 🦋

 $retval = $ebook->set_publisher('text' => 'My Publishing House',
                                 'id' => 'mypubid');

✨ `set_review(%args)` ✨

Sets the text and optionally the ID of the first <Review> element found (case-insensitive), creating the element if one didn't already exist. 📝

This is a Mobipocket-specific element, and if it needs to be created it will always be created under <x-metadata>, with fix_metastructure_oeb12() called to make sure <x-metadata> exists.

Returns 1 on success. Returns undef if no review text was specified.

🌸 Arguments 🌸

text — the description to use as the text of the element. If not specified, the method returns undef.
id (optional) — the ID to set on the element. If set and the ID is already in use, a warning is logged, the ID is removed from the other location, and it's assigned to this element.

🦋 Example 🦋

 $retval = $ebook->set_review('text' => 'This book is perfect!',
                              'id' => 'revid');

✨ `set_rights(%args)` ✨

Sets the text of the first dc:rights or dc:copyrights element found (case-insensitive). If the element it finds has the gi of dc:copyrights, it gets changed to dc:rights. Why? To correct certain noncompliant Mobipocket files. She's doing cleanup work, bestie. 🧹✨

Creates the element if one didn't exist. If a <dc-metadata> element exists underneath <metadata>, the title element gets created underneath the <dc-metadata> in OEB 1.2 format. Otherwise the title element gets created underneath <metadata> in OPF 2.0 format.

Returns 1 on success. Returns undef if no rights string was specified.

🌸 Arguments 🌸

text — the text of the element. If not specified, the method returns undef.
id (optional) — the ID to set on the element. If set and the ID is already in use, a warning is logged, but the method continues anyway. She's chill like that. 😌

✨ `set_spec($spec)` ✨

Sets the OEB specification to match when modifying OPF data. The allowable values are 'OEB12', 'OPF20', and 'MOBI12'. Three choices, all iconic. 👑

Returns 1 if successful. Returns undef and sets an error message if an unknown specification was set.

✨ `set_timestamp()` ✨

Sets the <meta property="dcterms:modified"> element to the current timestamp, and removes duplicate or nonstandard timestamps. Fresh. ⏰

✨ `set_title(%args)` ✨

Sets the text or id of the first dc:title element found (case-insensitive). Creates the element if one didn't exist. If a <dc-metadata> element exists underneath <metadata>, the title element gets created underneath the <dc-metadata> in OEB 1.2 format. Otherwise the title element gets created underneath <metadata> in OPF 2.0 format.

🌸 Arguments 🌸

set_title() takes two optional named arguments. If you specify neither, the method does absolutely nothing. Respect. 🫡

text — the text of the element. If not specified, and no title element is found, an error gets set and the method returns undef — set_title() will flat-out refuse to create a dc:title element with no text. She has standards. 💅
id

This specifies the ID to set on the element. If it's set and that ID is already in use, a warning gets logged but the method keeps on going anyway. No drama, just a lil note in the logs. 💅

`set_type(%args)` ✨

Sets the text and, if you want, the ID of the first dc:type element it finds (case-insensitive bestie, we don't do exact-match-only here). If that element doesn't exist yet? We create it. Simple as.

Now here's the little plot twist: if a <dc-metadata> element exists underneath <metadata>, the publisher element gets created underneath the <dc-metadata> in OEB 1.2 format. Otherwise the title element is created underneath <metadata> in OPF 2.0 format.

Returns 1 on success. Returns undef if no publisher was specified. 🫶

Arguments

set_type() takes one required and one optional named argument:

text — this specifies the publisher name to set as the text of the element. If you don't specify it, the method returns undef.
id (optional) — this specifies the ID to set on the element. If it's set and that ID is already in use, a warning is logged and the ID is removed from the other location and assigned to the element.

Example

 $retval = $ebook->set_type('text' => 'Short Story',
                            'id' => 'mytypeid');

🎀 PROCEDURES 🎀

Okay so all of these procedures are exportable, but none of them are exported by default, bestie. If you want the whole squad, use the :all tag. Group hug. 🫂

`_lc` 🌸

Wrapper for CORE::lc, and it exists purely to get around the fact that builtins can't be used in dispatch tables prior to Perl 5.16. Sneaky, effective, iconic.

WARNING: this procedure may disappear once Perl 5.16 is standard on all systems in common use! For that reason, this is not exportable. 💀

`_uc` 🌸

Wrapper for CORE::uc, same deal — gets around the fact that builtins can't be used in dispatch tables prior to Perl 5.16.

WARNING: this procedure may disappear once Perl 5.16 is standard on all systems in common use! For that reason, this is not exportable. 💀

`capitalize($string)` 👑

Capitalizes the first letter of each word in $string.

Returns the corrected string. Periodt. ✨

`clean_filename($string)` 🧚

Takes an input string and cleans out any characters that would not be valid in a filename.

Returns the cleaned string. Sparkly clean. 🌟

`create_epub_container($opffile)` 📦

Creates the XML file META-INF/container.xml pointing to the specified OPF file.

It creates the META-INF directory if necessary. It will destroy any non-directory file named META-INF in the current directory, so watch out. And if META-INF/container.xml already exists, it will rename that file to META-INF/container.xml.backup instead of just nuking it. Considerate queen behavior. 👑

Arguments

$opffile — the OPF filename (and path, if necessary) to use in the container. If not specified, it looks for a sole OPF file in the current working directory. Fails if more than one is found — no picking favorites. 🙈

Return values

Returns a twig representing the container data if successful, undef otherwise.

`create_epub_mimetype()` 🎀

Creates a file named mimetype in the current working directory containing application/epub+zip (no trailing newline — that detail MATTERS, don't let anyone tell you otherwise).

Destroys and overwrites that file if it exists. No hesitation.

Returns the mimetype string if successful, undef otherwise.

`debug($level,@message)` 🔍

Prints a debugging message to STDERR if the package variable $debug is greater than or equal to $level. A trailing newline is appended, and should not be part of @message.

Returns true or dies. Lowkey dramatic but we respect it.

`excerpt_line($text)` ✂️

Takes as an argument a list of text pieces that will be joined. If the joined length is less than 70, all of the joined text is returned.

If the joined length is greater than 70, the return string is the first 30 characters followed by ' [...] ' followed by the last 30 characters. Babygirl said "I'll show you the start and the end, the middle is none of your business." 💅

`find_in_path($pattern,@extradirs)` 🦋

Searches through $ENV{PATH} (and optionally any additional directories specified in @extradirs) for the first regular file matching $pattern.

$pattern itself can take two forms: if you pass it a qr// regular expression, that expression is used directly. If you pass any other string, that string is used for a case-insensitive exact match where the extension .bat, .com, or .exe is optional — i.e. the final pattern will be qr/^ $pattern (\.bat|\.com|\.exe)? $/ix.

Returns the first match found, or undef if there were no matches or if no pattern was specified. 💜

`find_links($filename)` 🔗

Searches through a file for href and src attributes, and returns a list of unique links with any named anchors removed (e.g. 'myfile.html#part7' comes back as just 'myfile.html'). If no links are found, or the file does not exist, returns undef.

Does not check to see if the links are local. Requires that links be surrounded by double quotes, not single or left bare. Assumes that any link will not be broken across multiple lines, so it will (for example) fail to find:

 <img src=
 "myfile.jpg">

though it can find:

 <img
  src="myfile.jpg">

This also does not distinguish between local files and remote links. Equal opportunity link finder, fr fr. 🌈

`find_opffile()` 🔎

Attempts to locate an OPF file, first by calling get_container_rootfile() to check the contents of META-INF/container.xml, and then by looking for a single file with the extension .opf in the current working directory.

Returns the filename of the OPF file, or undef if nothing was found. 🫶

`fix_datestring($datestring)` 📅

Takes a date string and attempts to convert it to the limited subset of ISO8601 allowed by the OPF standard (YYYY, YYYY-MM, or YYYY-MM-DD).

In the special case of finding MM/DD/YYYY, it assumes that it was a Mobipocket-mangled date, and not only converts it, but will strip the day information if the day is '01', and both the month and day information if both month and day are '01'. This is because Mobipocket Creator enforces a complete MM/DD/YYYY even if the month and day aren't known, and it is common practice to use 01 for an unknown value. Detective work tbh. 🕵️‍♀️

Arguments

$datestring — a date string in a format recognizable by Date::Manip.

Returns $fixeddate

$fixeddate : the corrected string, or undef on failure.

`get_container_rootfile($container)` 📂

Opens and parses an OPS/epub container, extracting the 'full-path' attribute of element 'rootfile'.

Arguments

$container — the OPS container to parse. Defaults to 'META-INF/container.xml'.

Return values

Returns a string containing the rootfile on success, undef on failure.

`hashvalue_key_self(\%hash, $modifier)` 🔑

Takes as an argument a hash reference and an optional modifier, and inserts a new key for every value in that hash if no such key already exists.

If the modifier is set to 'lc' or 'uc', the value is either lowercased or uppercased respectively before it is used as a key.

Croaks if the first argument is not a hashref, or if an invalid modifier string is used. It's not mad, it's just disappointed. 😭

`hexstring($bindata)` 💜

Takes as an argument a scalar containing a sequence of binary bytes. Returns a string converting each octet of the data to its two-digit hexadecimal equivalent. There is no leading "0x" on the string. Keep that in mind.

`print_memory($label)` 🧠

Checks /proc/$PID/statm and prints out a line to STDERR showing the current memory usage. This is a debugging tool that will likely fail to do anything useful on a system without a /proc system compatible with Linux. So like, ymmv bestie.

Arguments

$label — if defined, will be output along with the memory usage.

Returns 1 on success, undef otherwise.

`split_metadata($metahtmlfile, $metafile)` ✂️📄

Takes a psuedo-HTML containing one or more <metadata>...</metadata> blocks and splits out the metadata blocks into an XML file ready to be used as an OPF document. The input HTML file is rewritten without the metadata.

If $metafile (or the temporary HTML-only file created during the split) already exists, it will be moved to filename.backup. Safety first, always. 💅

Arguments

$metahtmlfile — the filename of the pseudo-HTML file.
$metafile (optional) — the filename to write out any extracted metadata. If not specified, will default to the basename of $metahtmlfile with '.opf' appended.

Returns the filename the metadata was written to, or undef if no metadata was found.

`split_pre($htmlfile,$outfilebase)` 🌸

Splits <pre>...</pre> blocks out of a source HTML file into their own separate HTML files including required headers. Each block will be written to its own file following the naming format "$outfilebase-###.html", where ### is a three-digit number beginning at 001 and incrementing for each block found. If $outfilebase is not specified, it defaults to the basename of $htmlfile with "-pre-###.html" appended. The

okay so the original manpage literally just trails off mid-sentence on a lonely little "The" and then moves right along to the next paragraph. Not me defending it, just reporting the facts 💀

Returns a list containing all filenames created. 🌟

`strip_script(%args)` 🚫

Strips any <script>...</script> blocks out of a HTML file.

Arguments

infile — specifies the input file. If not specified, the sub croaks.
outfile — specifies the output file. If not specified, it defaults to infile (i.e. the input file is overwritten). So, y'know, be aware. 🙈
noscript — if set to true, the sub will strip <noscript>...</noscript> blocks as well.

`system_result($caller,$retval,@syscmd)` 🫡

Checks the result of a system call and croaks on failure with an appropriate message. For this to work, it MUST be used as the line immediately following the system command. Immediate. Adjacent. No sneaking anything in between.

Arguments

$caller — the calling function (used in output message).
$retval — the return value of the system command.
@syscmd — the array passed to the system call.

Return Values

Returns 0 on success.
Croaks on failure. 💀

`system_tidy_xhtml($infile,$outfile)` ✨

Runs tidy on a XHTML file semi-safely (using a secondary file).

Converts HTML to XHTML if necessary.

Arguments

$infile — the filename to tidy.
$outfile — the filename to use for tidy output if the safety condition to overwrite the input file isn't met. Defaults to "infile-tidy.ext" if not specified.

Global variables used

$tidycmd — the location of the tidy executable.
$tidyxhtmlerrors — the filename to use to output errors.
$tidysafety — the safety factor to use (see CONFIGURABLE GLOBAL VARIABLES, above).

Return Values

Returns the return value from tidy:

0 — no errors
1 — warnings only
2 — errors

Dies horribly if the return value is unexpected. Not "dies", dies horribly. Read the room. 😭

`system_tidy_xml($infile,$outfile)` 🌈

Runs tidy on an XML file semi-safely (using a secondary file).

Arguments

$infile — the filename to tidy.
$outfile (optional) — the filename to use for tidy output if the safety condition to overwrite the input file isn't met. Defaults to "infile-tidy.ext" if not specified.

Global variables used

$tidycmd — the name of the tidy executable.
$tidyxmlerrors — the filename to use to output errors.
$tidysafety — the safety factor to use (see CONFIGURABLE GLOBAL VARIABLES, above).

Return values

Returns the return value from tidy. 🫶

okay bestie, the return codes are giving:

0 — no errors
1 — warnings only
2 — errors

And if the return value is unexpected? it dies horribly. 💀

"trim"

Removes any whitespace characters from the beginning or end of every string in @list (also works on scalars). so clean, so fresh ✨

trim;               # trims $_ inplace
$new = trim;        # trims (and returns) a copy of $_
trim $str;          # trims $str inplace
$new = trim $str;   # trims (and returns) a copy of $str
trim @list;         # trims @list inplace
@new = trim @list;  # trims (and returns) a copy of @list

This was shamelessly copied from japhy's example at perlmonks.org: http://www.perlmonks.org/?node_id=36684.

If needed for large lists, it would probably be better to use String::Strip.

twigelt_create_uuid($gi)

Creates an unlinked element with the specified gi (tag), and then assigns it the id and scheme attributes 'UUID'. iconic behavior tbh 🦋

Arguments

$gi — The gi (tag) to use for the element. Default: 'dc:identifier'

Returns the element.

"twigelt_detect_duplicate($element1, $element2)"

Takes two twig elements and returns 1 if they have the same GI (tag), text, and attributes, but are not actually the same element. The GI comparison is case-insensitive. The others are case-sensitive. fr fr, read that twice

Returns 0 otherwise.

Croaks if passed anything but twig elements.

twigelt_fix_oeb12_atts($element)

Checks the attributes in a twig element to see if they match OPF names with an opf: namespace, and if so, removes the namespace. Used by the fix_oeb12() method.

Takes as a sole argument a twig element.

Returns that element with the modified attributes, or undef if the element didn't exist. Returns an unmodified element if both att and opf:att exist.

twigelt_fix_opf20_atts($element)

Checks the attributes in a twig element to see if they match OPF names, and if so, prepends the OPF namespace. Used by the fix_opf20() method.

Takes as a sole argument a twig element.

Returns that element with the modified attributes, or undef if the element didn't exist.

twigelt_is_author($element)

Takes as an argument a twig element. Returns true if the element is a dc:creator (case-insensitive) with either a opf:role="aut" or role="aut" attribute defined. Returns undef otherwise, and also if the element has no text.

Croaks if fed no argument, or fed an argument that isn't a twig element.

Intended to be used as a twig search condition.

Example

my @elements = $ebook->twigroot->descendants(\&twigelt_is_author);

twigelt_is_isbn($element)

Takes as an argument a twig element. Returns true if the element is a dc:identifier (case-insensitive) where any of the id, opf:scheme, or scheme attributes start with 'isbn', '-isbn', 'eisbn', or 'e-isbn' (again case-insensitive). the way that's so specific 💅

Returns undef otherwise, and also if the element has no text.

Croaks if fed no argument, or fed an argument that isn't a twig element.

Intended to be used as a twig search condition.

Example

my @elements = $ebook->twigroot->descendants(\&twigelt_is_isbn);

twigelt_is_knownuid($element)

Takes as an argument a twig element. Returns true if the element is a dc:identifier (case-insensitive) element with an "id" attribute matching the known IDs of proper unique identifiers suitable for a package-id (also case-insensitive). Returns undef otherwise.

Croaks if fed no argument, or fed an argument that isn't a twig element.

Intended to be used as a twig search condition.

Example

my @elements = $ebook->twigroot->descendants(\&twigelt_is_knownuid);

usedir($dir)

Changes the current working directory to the one specified, creating it if necessary. lowkey a main character move 🌸

Returns the current working directory before the change. If no directory is specified, returns the current working directory without changing anything.

Croaks on any failure.

userconfigdir()

Returns the directory in which user configuration files and helper programs are expected to be found, creating that directory if it does not exist. Typically, this directory is "$ENV{HOME}/.ebooktools", but on MSWin32 systems if that directory does not already exist, "$ENV{USERPROFILE}/ApplicationData/EBook-Tools" is returned (and potentially created) instead.

If $ENV{HOME} (and $ENV{USERPROFILE} on MSWin32) are either not set or do not point to a directory, the sub returns undef.

"ymd_validate($year,$month,$day)"

Make sure month and day have valid values. Return the passed values if they are, return 3 undefs if not. Testing of month or day can be skipped by passing undef in that spot. validating, but make it cute 🎀

🫠 BUGS AND LIMITATIONS 🫠

fix_links() could be improved to download remote URIs instead of ignoring them.
fix_links() needs to check the <reference> links under <guide>
fix_links() needs to be redone with HTML::TreeBuilder or Mojo::DOM to avoid the weakness with newlines between attribute names and values
Need to implement fix_tours() that should collect the related elements and delete the parent if none are found. Empty <tours> elements aren't allowed.
fix_languages() needs to convert language names into IANA language codes.
set_language() should add a warning if the text isn't a valid IANA language code.
NCX generation only generates from the spine. It should be possible to use a TOC html file for generation instead. In the long term, it should be possible to generate one from the headers and anchors in arbitrary HTML files.
It might be better to use sysread / index / substr / syswrite in &split_metadata to handle the split in 10k chunks, to avoid massive memory usage on large files.

This may not be worth the effort, since the average size for most books is less than 500k, and the largest books are rarely over 10M.

The only generator is currently for .epub books. PDF, PalmDoc, Mobipocket, Plucker, and iSiloX are eventually planned.
Although I like keeping warnings associated with the ebook object, it may be better to throw exceptions on errors and catch them later. This probably won't be implemented until it bites someone who complains, though.
Unit tests are incomplete

👑 AUTHOR 👑

Zed Pobre <zed@debian.org>

💖 LICENSE AND COPYRIGHT 💖

Licensed to the public under the terms of the GNU GPL, version 2

and that's the whole vibe, bestie ✨ This page is from perl v5.40.0, dated 2025-01-10, and it's EBook::Tools(3pm). Slay. 💅🫶

📦 where this page comes from

debian trixie: libebook-tools-perl 0.5.4-2 · GPL-2.0-only
ubuntu resolute: libebook-tools-perl 0.5.4-2 · GPL-2.0-only
ubuntu stonking: libebook-tools-perl 0.5.4-2 · GPL-2.0-only
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-11-03: a language model's rewrite of the original, under its terms

EBook::Tools(3pm)

EBook::Tools(3pm) — User Contributed Perl Documentation 💖

✨ NAME ✨

🌸 DESCRIPTION 🌸

🦋 SYNOPSIS 🦋

🎀 DEPENDENCIES 🎀

💖 Perl Modules 💖

🦋 Other Programs 🦋

💜 CONFIGURABLE PACKAGE VARIABLES 💜

🎀 CONSTRUCTORS AND INITIALIZATION 🎀

new($filename)

init($filename)

init_blank(%args)

Arguments

Example

🌈 ACCESSOR METHODS 🌈

adult()

contributor_list()

coverimage()

date_list(%args)

Arguments

description()

element_list(%args)

Arguments

errors()

identifier()

isbn_list(%args)

isbns(%args)

languages()

manifest(%args)

manifest_hrefs()

opf_namespace()

opfdir()

opffile()

opfpath()

primary_author()

print_errors()

print_warnings()

print_opf()

publishers()

retailprice()

review()

rights('id' => 'identifier')

search_knownuids()

search_knownuidschemes()

spec()

spine()

spine_idrefs()

subject_list()

title()

twig()

twigcheck()

twigroot()

warnings()

🛠️ MODIFIER METHODS 🛠️

add_document($href,$id,$mediatype)

$id 💅

$mediatype (optional)

add_error(@errors) 😭

add_identifier(%args) 🎀

Arguments

add_item($href,$id,$mediatype) 🦋

Arguments

$href

$id

$mediatype (optional)

add_metadata(%args) 🌸

Arguments

"gi"

"parent"

"text"

"id" (optional)

"fileas" (optional)

"role" (optional)

"scheme" (optional)

Example

add_subject(%args) 🍓

Arguments

add_warning(@newwarning) 🙈

clear_errors() 🧚

`new($filename)`

`init($filename)`

`init_blank(%args)`

`adult()`

`contributor_list()`

`coverimage()`

`date_list(%args)`

`description()`

`element_list(%args)`

`errors()`

`identifier()`

`isbn_list(%args)`

`isbns(%args)`

`languages()`

`manifest(%args)`

`manifest_hrefs()`

`opf_namespace()`

`opfdir()`

`opffile()`

`opfpath()`

`primary_author()`

`print_errors()`

`print_warnings()`

`print_opf()`

`publishers()`

`retailprice()`

`review()`

`rights('id' => 'identifier')`

`search_knownuids()`

`search_knownuidschemes()`

`spec()`

`spine()`

`spine_idrefs()`

`subject_list()`

`title()`

`twig()`

`twigcheck()`

`twigroot()`

`warnings()`

`add_document($href,$id,$mediatype)`

`$id` 💅

`$mediatype` (optional)

`add_error(@errors)` 😭

`add_identifier(%args)` 🎀

`add_item($href,$id,$mediatype)` 🦋

`$href`

`$id`

`$mediatype` (optional)

`add_metadata(%args)` 🌸

`"gi"`

`"parent"`

`"text"`

`"id"` (optional)

`"fileas"` (optional)

`"role"` (optional)

`"scheme"` (optional)

`add_subject(%args)` 🍓

`add_warning(@newwarning)` 🙈

`clear_errors()` 🧚

`clear_warnerr()` 🌈

`clear_warnings()` ⭐

`delete_meta_filepos()` 💀

`delete_subject(%args)` 🎀

`fix_creators()` 👑

`fix_dates()` 🦋

`fix_guide()` 🔥

`fix_languages(%args)` 🌸

`fix_links()` 🫶

`fix_manifest()` 💜

`fix_metastructure_basic()` 🌟

`fix_metastructure_oeb12()` 🧚

`fix_misc()` ✨

`fix_mobi()` 🌈

✨ `set_meta(%args)` ✨

✨ `set_metadata(%args)` ✨

✨ `set_opffile($filename)` ✨

✨ `set_retailprice(%args)` ✨

✨ `set_primary_author(%args)` ✨

✨ `set_publisher(%args)` ✨

✨ `set_review(%args)` ✨