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BTOOL_FAQ(1)                        btparse                       BTOOL_FAQ(1)


NAME

       btool_faq - Frequently-Asked Questions about btparse and Text::BibTeX


DESCRIPTION

       This document attempts to address questions that I have been asked
       several times, and are easy to answer -- but not by perusing the
       documentation.  For various reasons, the answers tend to be thinly
       distributed across several man pages, making it difficult to figure out
       what's going on.  Hence, this man page will attempt to tie together
       various strands of thought, providing quick, focused, "How do I do X?"
       answers as opposed to lengthy descriptions of the capabilities and
       conventions of the btOOL libraries.


PERL LIBRARY

       This section covers questions that users of "Text::BibTeX", the Perl
       component of btOOL, have asked.

   Why aren't the BibTeX "month" macros defined?
       Because they're bibliography-specific, and "Text::BibTeX" by default
       doesn't impose any assumptions about a particular type of database or
       data-processing domain on your entries.  The problem arises when you
       parse entries from a file, say foo.bib that quite sensibly use the
       month macros ("jan", "feb", etc.) provided by the BibTeX standard style
       files:

          $bibfile = new Text::BibTeX::File 'foo.bib'    # open file
             or die "foo.bib: $!\n";
          $entry = new Text::BibTeX::Entry $bibfile;     # parse first entry

       Using this code, you might get an "undefined macro" warning for every
       entry parsed from foo.bib.  Apart from the superficial annoyance of all
       those warning messages, the undefined macros are expanded as empty
       strings, meaning you lose any information about them---not good.

       You could always kludge it and forcibly define the month macros
       yourself.  Prior to release 0.30, this had to be done by parsing a set
       of fake entries, but now "Text::BibTeX" provides a direct interface to
       the underlying macro table.  You could just do this before parsing any
       entries:

          use Text::BibTeX qw(:macrosubs);
          # ...
          my %month = (jan => 'January', feb => 'February', ... );
          add_macro_text ($macro, $value)
             while (($macro, $value) = each %month);

       But there's a better way that's more in keeping with how things are
       done under BibTeX (where default macros are defined in the style file):
       use "Text::BibTeX"'s object-oriented analogue to style files, called
       structure modules.  "Text::BibTeX" provides a structure module,
       "Text::BibTeX::Bib", that (partially) emulates the standard style files
       of BibTeX 0.99, including the definition of month macros.  Structure
       modules are specified on a per-file basis by using the "set_structure"
       method on a "Text::BibTeX::File" object.  It's quite simple to tell
       "Text::BibTeX" that entries from $bibfile are expected to conform to
       the "Bib" structure (which is implemented by the "Text::BibTeX::Bib"
       module, but you don't really need to know that):

          $bibfile = new Text::BibTeX::File 'foo.bib'
             or die "foo.bib: $!\n";
          $bibfile->set_structure ('Bib');

       You probably shouldn't hardcode the name of a particular structure in
       your programs, though, as there will eventually be a multitude of
       structure modules to choose from (just as there are a multitude of
       BibTeX style files to choose from).  My preferred approach is to make
       the structure a command-line option which defaults to "Bib" (since
       that's the only structure actually implemented as of this writing).

   How do I append to a BibTeX file?
       Just open it in append mode, and write entries to it as usual.
       Remember, a "Text::BibTeX::File" object is mainly a wrapper around an
       "IO::File" object, and the "Text::BibTeX::File::open" method (and thus
       "new" as well) is just a front-end to "IO::File::open".
       "IO::File::open", in turn, is a front-end either to Perl's builtin
       "open" (if called with one argument) or "sysopen" (two or three
       arguments).  To save you the trouble of going off and reading all those
       man pages, here's the trick: if you pass just a filename to
       "Text::BibTeX::File"'s "new" method, then it's treated just like a
       filename passed to Perl's builtin "open":

          my $append_file = new Text::BibTeX::File ">>$filename"
             or die "couldn't open $filename for appending: $!\n";

       opens $filename for appending.  If, later on, you have an entry from
       another file (say $entry), then you can append it to $append_file by
       just writing it as usual:

          $entry->write ($append_file);

       See "append_entries" in the examples/ subdirectory of the
       "Text::BibTeX" distribution for a complete example.


C LIBRARY

       This section covers frequently-asked questions about btparse, the C
       component of btOOL.

   Is there a Python binding for btparse yet?
       Not that I know of.  I haven't written one.  If you do so, please let
       me know about it.


SEE ALSO

       btparse, Text::BibTeX


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.

btparse, version 0.71             2015-05-28                      BTOOL_FAQ(1)

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