Provided by: libtext-bibtex-perl_0.89-1build3_amd64 
NAME
Text::BibTeX - interface to read and parse BibTeX files
SYNOPSIS
use Text::BibTeX;
my $bibfile = Text::BibTeX::File->new("foo.bib");
my $newfile = Text::BibTeX::File->new(">newfoo.bib");
while ($entry = Text::BibTeX::Entry->new($bibfile))
{
next unless $entry->parse_ok;
. # hack on $entry contents, using various
. # Text::BibTeX::Entry methods
.
$entry->write ($newfile);
}
DESCRIPTION
The "Text::BibTeX" module serves mainly as a high-level introduction to the "Text::BibTeX" library, for
both code and documentation purposes. The code loads the two fundamental modules for processing BibTeX
files ("Text::BibTeX::File" and "Text::BibTeX::Entry"), and this documentation gives a broad overview of
the whole library that isn't available in the documentation for the individual modules that comprise it.
In addition, the "Text::BibTeX" module provides a number of miscellaneous functions that are useful in
processing BibTeX data (especially the kind that comes from bibliographies as defined by BibTeX 0.99,
rather than generic database files). These functions don't generally fit in the object-oriented class
hierarchy centred around the "Text::BibTeX::Entry" class, mainly because they are specific to
bibliographic data and operate on generic strings (rather than being tied to a particular BibTeX entry).
These are also documented here, in "MISCELLANEOUS FUNCTIONS".
Note that every module described here begins with the "Text::BibTeX" prefix. For brevity, I have dropped
this prefix from most class and module names in the rest of this manual page (and in most of the other
manual pages in the library).
MODULES AND CLASSES
The "Text::BibTeX" library includes a number of modules, many of which provide classes. Usually, the
relationship is simple and obvious: a module provides a class of the same name---for instance, the
"Text::BibTeX::Entry" module provides the "Text::BibTeX::Entry" class. There are a few exceptions,
though: most obviously, the "Text::BibTeX" module doesn't provide any classes itself, it merely loads two
modules ("Text::BibTeX::Entry" and "Text::BibTeX::File") that do. The other exceptions are mentioned in
the descriptions below, and discussed in detail in the documentation for the respective modules.
The modules are presented roughly in order of increasing specialization: the first three are essential
for any program that processes BibTeX data files, regardless of what kind of data they hold. The later
modules are specialized for use with bibliographic databases, and serve both to emulate BibTeX 0.99's
standard styles and to provide an example of how to define a database structure through such specialized
modules. Each module is fully documented in its respective manual page.
"Text::BibTeX"
Loads the two fundamental modules ("Entry" and "File"), and provides a number of miscellaneous
functions that don't fit anywhere in the class hierarchy.
"Text::BibTeX::File"
Provides an object-oriented interface to BibTeX database files. In addition to the obvious
attributes of filename and filehandle, the "file" abstraction manages properties such as the database
structure and options for it.
"Text::BibTeX::Entry"
Provides an object-oriented interface to BibTeX entries, which can be parsed from "File" objects,
arbitrary filehandles, or strings. Manages all the properties of a single entry: type, key, fields,
and values. Also serves as the base class for the structured entry classes (described in detail in
Text::BibTeX::Structure).
"Text::BibTeX::Value"
Provides an object-oriented interface to values and simple values, high-level constructs that can be
used to represent the strings associated with each field in an entry. Normally, field values are
returned simply as Perl strings, with macros expanded and multiple strings "pasted" together. If
desired, you can instruct "Text::BibTeX" to return "Text::BibTeX::Value" objects, which give you
access to the original form of the data.
"Text::BibTeX::Structure"
Provides the "Structure" and "StructuredEntry" classes, which serve primarily as base classes for the
two kinds of classes that define database structures. Read this man page for a comprehensive
description of the mechanism for implementing Perl classes analogous to BibTeX "style files".
"Text::BibTeX::Bib"
Provides the "BibStructure" and "BibEntry" classes, which serve two purposes: they fulfill the same
role as the standard style files of BibTeX 0.99, and they give an example of how to write new
database structures. These ultimately derive from, respectively, the "Structure" and
"StructuredEntry" classes provided by the "Structure" module.
"Text::BibTeX::BibSort"
One of the "BibEntry" class's base classes: handles the generation of sort keys for sorting prior to
output formatting.
"Text::BibTeX::BibFormat"
One of the "BibEntry" class's base classes: handles the formatting of bibliographic data for output
in a markup language such as LaTeX.
"Text::BibTeX::Name"
A class used by the "Bib" structure and specific to bibliographic data as defined by BibTeX itself:
parses individual author names into "first", "von", "last", and "jr" parts.
"Text::BibTeX::NameFormat"
Also specific to bibliographic data: puts split-up names (as parsed by the "Name" class) back
together in a custom way.
For a first time through the library, you'll probably want to confine your reading to Text::BibTeX::File
and Text::BibTeX::Entry. The other modules will come in handy eventually, especially if you need to
emulate BibTeX in a fairly fine grained way (e.g. parsing names, generating sort keys). But for the
simple database hacks that are the bread and butter of the "Text::BibTeX" library, the "File" and "Entry"
classes are the bulk of what you'll need. You may also find some of the material in this manual page
useful, namely "CONSTANT VALUES" and "UTILITY FUNCTIONS".
EXPORTS
The "Text::BibTeX" module has a number of optional exports, most of them constant values described in
"CONSTANT VALUES" below. The default exports are a subset of these constant values that are used
particularly often, the "entry metatypes" (also accessible via the export tag "metatypes"). Thus, the
following two lines are equivalent:
use Text::BibTeX;
use Text::BibTeX qw(:metatypes);
Some of the various subroutines provided by the module are also exportable. "bibloop", "split_list",
"purify_string", and "change_case" are all useful in everyday processing of BibTeX data, but don't really
fit anywhere in the class hierarchy. They may be imported from "Text::BibTeX" using the "subs" export
tag. "check_class" and "display_list" are also exportable, but only by name; they are not included in
any export tag. (These two mainly exist for use by other modules in the library.) For instance, to use
"Text::BibTeX" and import the entry metatype constants and the common subroutines:
use Text::BibTeX qw(:metatypes :subs);
Another group of subroutines exists for direct manipulation of the macro table maintained by the
underlying C library. These functions (see "Macro table functions", below) allow you to define, delete,
and query the value of BibTeX macros (or "abbreviations"). They may be imported en masse using the
"macrosubs" export tag:
use Text::BibTeX qw(:macrosubs);
CONSTANT VALUES
The "Text::BibTeX" module makes a number of constant values available. These correspond to the values of
various enumerated types in the underlying C library, btparse, and their meanings are more fully
explained in the btparse documentation.
Each group of constants is optionally exportable using an export tag given in the descriptions below.
Entry metatypes
"BTE_UNKNOWN", "BTE_REGULAR", "BTE_COMMENT", "BTE_PREAMBLE", "BTE_MACRODEF". The "metatype" method
in the "Entry" class always returns one of these values. The latter three describe, respectively,
"comment", "preamble", and "string" entries; "BTE_REGULAR" describes all other entry types.
"BTE_UNKNOWN" should never be seen (it's mainly useful for C code that might have to detect half-
baked data structures). See also btparse. Export tag: "metatypes".
AST node types
"BTAST_STRING", "BTAST_MACRO", "BTAST_NUMBER". Used to distinguish the three kinds of simple
values---strings, macros, and numbers. The "SimpleValue" class' "type" method always returns one of
these three values. See also Text::BibTeX::Value, btparse. Export tag: "nodetypes".
Name parts
"BTN_FIRST", "BTN_VON", "BTN_LAST", "BTN_JR", "BTN_NONE". Used to specify the various parts of a
name after it has been split up. These are mainly useful when using the "NameFormat" class. See
also bt_split_names and bt_format_names. Export tag: "nameparts".
Join methods
"BTJ_MAYTIE", "BTJ_SPACE", "BTJ_FORCETIE", "BTJ_NOTHING". Used to tell the "NameFormat" class how to
join adjacent tokens together; see Text::BibTeX::NameFormat and bt_format_names. Export tag:
"joinmethods".
UTILITY FUNCTIONS
"Text::BibTeX" provides several functions that operate outside of the normal class hierarchy. Of these,
only "bibloop" is likely to be of much use to you in writing everyday BibTeX-hacking programs; the other
two ("check_class" and "display_list") are mainly provided for the use of other modules in the library.
They are documented here mainly for completeness, but also because they might conceivably be useful in
other circumstances.
bibloop (ACTION, FILES [, DEST])
Loops over all entries in a set of BibTeX files, performing some caller-supplied action on each
entry. FILES should be a reference to the list of filenames to process, and ACTION a reference to a
subroutine that will be called on each entry. DEST, if given, should be a "Text::BibTeX::File"
object (opened for output) to which entries might be printed.
The subroutine referenced by ACTION is called with exactly one argument: the "Text::BibTeX::Entry"
object representing the entry currently being processed. Information about both the entry itself and
the file where it originated is available through this object; see Text::BibTeX::Entry. The ACTION
subroutine is only called if the entry was successfully parsed; any syntax errors will result in a
warning message being printed, and that entry being skipped. Note that all successfully parsed
entries are passed to the ACTION subroutine, even "preamble", "string", and "comment" entries. To
skip these pseudo-entries and only process "regular" entries, then your action subroutine should look
something like this:
sub action {
my $entry = shift;
return unless $entry->metatype == BTE_REGULAR;
# process $entry ...
}
If your action subroutine needs any more arguments, you can just create a closure (anonymous
subroutine) as a wrapper, and pass it to "bibloop":
sub action {
my ($entry, $extra_stuff) = @_;
# ...
}
my $extra = ...;
Text::BibTeX::bibloop (sub { &action ($_[0], $extra) }, \@files);
If the ACTION subroutine returns a true value and DEST was given, then the processed entry will be
written to DEST.
check_class (PACKAGE, DESCRIPTION, SUPERCLASS, METHODS)
Ensures that a PACKAGE implements a class meeting certain requirements. First, it inspects Perl's
symbol tables to ensure that a package named PACKAGE actually exists. Then, it ensures that the
class named by PACKAGE derives from SUPERCLASS (using the universal method "isa"). This derivation
might be through multiple inheritance, or through several generations of a class hierarchy; the only
requirement is that SUPERCLASS is somewhere in PACKAGE's tree of base classes. Finally, it checks
that PACKAGE provides each method listed in METHODS (a reference to a list of method names). This is
done with the universal method "can", so the methods might actually come from one of PACKAGE's base
classes.
DESCRIPTION should be a brief string describing the class that was expected to be provided by
PACKAGE. It is used for generating warning messages if any of the class requirements are not met.
This is mainly used by the supervisory code in "Text::BibTeX::Structure", to ensure that user-
supplied structure modules meet the rules required of them.
display_list (LIST, QUOTE)
Converts a list of strings to the grammatical conventions of a human language (currently, only
English rules are supported). LIST must be a reference to a list of strings. If this list is empty,
the empty string is returned. If it has one element, then just that element is returned. If it has
two elements, then they are joined with the string " and " and the resulting string is returned.
Otherwise, the list has N elements for N >= 3; elements 1..N-1 are joined with commas, and the final
element is tacked on with an intervening ", and ".
If QUOTE is true, then each string is encased in single quotes before anything else is done.
This is used elsewhere in the library for two very distinct purposes: for generating warning messages
describing lists of fields that should be present or are conflicting in an entry, and for generating
lists of author names in formatted bibliographies.
MISCELLANEOUS FUNCTIONS
In addition to loading the "File" and "Entry" modules, "Text::BibTeX" loads the XSUB code which bridges
the Perl modules to the underlying C library, btparse. This XSUB code provides a number of miscellaneous
utility functions, most of which are put into other packages in the "Text::BibTeX" family for use by the
corresponding classes. (For instance, the XSUB code loaded by "Text::BibTeX" provides a function
"Text::BibTeX::Entry::parse", which is actually documented as the "parse" method of the
"Text::BibTeX::Entry" class---see Text::BibTeX::Entry. However, for completeness this function---and all
the other functions that become available when you "use Text::BibTeX"---are at least mentioned here. The
only functions from this group that you're ever likely to use are described in "Generic string-processing
functions".
Startup/shutdown functions
These just initialize and shutdown the underlying C library. Don't call either one of them; the
"Text::BibTeX" startup/shutdown code takes care of it as appropriate. They're just mentioned here for
completeness.
initialize ()
cleanup ()
Generic string-processing functions
split_list (STRING, DELIM [, FILENAME [, LINE [, DESCRIPTION [, OPTS]]]])
Splits a string on a fixed delimiter according to the BibTeX rules for splitting up lists of names.
With BibTeX, the delimiter is hard-coded as "and"; here, you can supply any string. Instances of
DELIM in STRING are considered delimiters if they are at brace-depth zero, surrounded by whitespace,
and not at the beginning or end of STRING; the comparison is case-insensitive. See bt_split_names
for full details of how splitting is done (it's not the same as Perl's "split" function). OPTS is a
hash ref of the same binmode and normalization arguments as with, e.g. Text::BibTeX::File->open().
split_list calls isplit_list() internally but handles UTF-8 conversion and normalization, if
requested.
Returns the list of strings resulting from splitting STRING on DELIM.
isplit_list (STRING, DELIM [, FILENAME [, LINE [, DESCRIPTION]]])
Splits a string on a fixed delimiter according to the BibTeX rules for splitting up lists of names.
With BibTeX, the delimiter is hard-coded as "and"; here, you can supply any string. Instances of
DELIM in STRING are considered delimiters if they are at brace-depth zero, surrounded by whitespace,
and not at the beginning or end of STRING; the comparison is case-insensitive. See bt_split_names
for full details of how splitting is done (it's not the same as Perl's "split" function). This
function returns bytes. Use Text::BibTeX::split_list to specify the same binmode and normalization
arguments as with, e.g. Text::BibTeX::File->open()
Returns the list of strings resulting from splitting STRING on DELIM.
purify_string (STRING [, OPTIONS])
"Purifies" STRING in the BibTeX way (usually for generation of sort keys). See bt_misc for details;
note that, unlike the C interface, "purify_string" does not modify STRING in-place. A purified copy
of the input string is returned.
OPTIONS is currently unused.
change_case (TRANSFORM, STRING [, OPTIONS])
Transforms the case of STRING according to TRANSFORM (a single character, one of 'u', 'l', or 't').
See bt_misc for details; again, "change_case" differs from the C interface in that STRING is not
modified in-place---the input string is copied, and the transformed copy is returned.
Entry-parsing functions
Although these functions are provided by the "Text::BibTeX" module, they are actually in the
"Text::BibTeX::Entry" package. That's because they are implemented in C, and thus loaded with the XSUB
code that "Text::BibTeX" loads; however, they are actually methods in the "Text::BibTeX::Entry" class.
Thus, they are documented as methods in Text::BibTeX::Entry.
parse (ENTRY_STRUCT, FILENAME, FILEHANDLE)
parse_s (ENTRY_STRUCT, TEXT)
Macro table functions
These functions allow direct access to the macro table maintained by btparse, the C library underlying
"Text::BibTeX". In the normal course of events, macro definitions always accumulate, and are only
defined as a result of parsing a macro definition (@string) entry. btparse never deletes old macro
definitions for you, and doesn't have any built-in default macros. If, for example, you wish to start
fresh with new macros for every file, use "delete_all_macros". If you wish to pre-define certain macros,
use "add_macro_text". (But note that the "Bib" structure, as part of its mission to emulate BibTeX 0.99,
defines the standard "month name" macros for you.)
See also bt_macros in the btparse documentation for a description of the C interface to these functions.
add_macro_text (MACRO, TEXT [, FILENAME [, LINE]])
Defines a new macro, or redefines an old one. MACRO is the name of the macro, and TEXT is the text
it should expand to. FILENAME and LINE are just used to generate any warnings about the macro
definition. The only such warning occurs when you redefine an old macro: its value is overridden,
and add_macro_text() issues a warning saying so.
delete_macro (MACRO)
Deletes a macro from the macro table. If MACRO isn't defined, takes no action.
delete_all_macros ()
Deletes all macros from the macro table, even the predefined month names.
macro_length (MACRO)
Returns the length of a macro's expansion text. If the macro is undefined, returns 0; no warning is
issued.
macro_text (MACRO [, FILENAME [, LINE]])
Returns the expansion text of a macro. If the macro is not defined, issues a warning and returns
"undef". FILENAME and LINE, if supplied, are used for generating this warning; they should be
supplied if you're looking up the macro as a result of finding it in a file.
Name-parsing functions
These are both private functions for the use of the "Name" class, and therefore are put in the
"Text::BibTeX::Name" package. You should use the interface provided by that class for parsing names in
the BibTeX style.
_split (NAME_STRUCT, NAME, FILENAME, LINE, NAME_NUM, KEEP_CSTRUCT)
free (NAME_STRUCT)
Name-formatting functions
These are private functions for the use of the "NameFormat" class, and therefore are put in the
"Text::BibTeX::NameFormat" package. You should use the interface provided by that class for formatting
names in the BibTeX style.
create ([PARTS [, ABBREV_FIRST]])
free (FORMAT_STRUCT)
_set_text (FORMAT_STRUCT, PART, PRE_PART, POST_PART, PRE_TOKEN, POST_TOKEN)
_set_options (FORMAT_STRUCT, PART, ABBREV, JOIN_TOKENS, JOIN_PART)
format_name (NAME_STRUCT, FORMAT_STRUCT)
BUGS AND LIMITATIONS
"Text::BibTeX" inherits several limitations from its base C library, btparse; see "BUGS AND LIMITATIONS"
in btparse for details. In addition, "Text::BibTeX" will not work with a Perl binary built using the
"sfio" library. This is because Perl's I/O abstraction layer does not extend to third-party C libraries
that use stdio, and btparse most certainly does use stdio.
SEE ALSO
btool_faq, Text::BibTeX::File, Text::BibTeX::Entry, Text::BibTeX::Value
AUTHOR
Greg Ward <gward@python.net>
COPYRIGHT
Copyright (c) 1997-2000 by Gregory P. Ward. All rights reserved. This file is part of the Text::BibTeX
library. This library is free software; you may redistribute it and/or modify it under the same terms as
Perl itself.
perl v5.38.2 2024-03-31 Text::BibTeX(3pm)