BIBCLEAN(1)

NAME
bibclean - prettyprint and syntax check BibTeX and Scribe bibliography data base files

SYNOPSIS
bibclean [ -author ] [ -copyleft ] [ -copyright ]
[ -error-log filename ] [ -help ] [ '-?' ]
[ -init-file filename ] [ -ISBN-file filename ]
[ -keyword-file filename ] [ -max-width nnn ]
[ -[no-]align-equals ] [ -[no-]brace-protect ]
[ -[no-]check-values ] [ -[no-]debug-match-failures ]
[ -[no-]delete-empty-values ] [ -[no-]file-position ]
[ -[no-]fix-accents ] [ -[no-]fix-braces ]
[ -[no-]fix-degrees ] [ -[no-]fix-font-changes ]
[ -[no-]fix-initials ] [ -[no-]fix-math ] [ -[no-]fix-names ]
[ -[no-]German-style ] [ -[no-]keep-linebreaks ]
[ -[no-]keep-parbreaks ] [ -[no-]keep-preamble-spaces ]
[ -[no-]keep-spaces ] [ -[no-]keep-string-spaces ]
[ -[no-]parbreaks ] [ -[no-]prettyprint ]
[ -[no-]print-ISBN-table ] [ -[no-]print-keyword-table ]
[ -[no-]print-patterns ] [ -[no-]quiet ]
[ -[no-]read-init-files ] [ -[no-]remove-OPT-prefixes ]
[ -[no-]scribe ] [ -[no-]trace-file-opening ]
[ -[no-]warnings ] [ -output-file filename ] [ -version ]
<infile or bibfile1 bibfile2 bibfile3 ...
>outfile

All options can be abbreviated to a unique leading prefix.

An explicit file name of ``-'' represents standard input; it is assumed if no input files are specified.

On VAX VMS and IBM PC DOS, the leading ``-'' on option names may be replaced by a slash, ``/''; however, the ``-'' option prefix is always recognized.

DESCRIPTION
bibclean prettyprints input BibTeX files to stdout, or to a user-specified file, and checks the brace balance and bibliography entry syntax as well. It can be used to detect problems in BibTeX files that sometimes confuse even BibTeX itself, and importantly, can be used to normalize the appearance of collections of BibTeX files.

Here is a summary of the formatting actions:

•   BibTeX items are formatted into a consistent structure with one field = "value" pair per line, and the initial @ and trailing right brace in column 1.

•   Tabs are expanded into blank strings; their use is discouraged because they inhibit portability, and can suffer corruption in electronic mail.

•   Long string values are split at a blank and continued onto the next line with leading indentation.

•   A single blank line separates adjacent bibliography entries.

•   Text outside BibTeX entries is passed through verbatim.

•   Outer parentheses around entries are converted to braces.

•   Personal names in author and editor field values are normalized to the form ``P. D. Q. Bach'', from ``P.D.Q. Bach'' and ``Bach, P.D.Q.''.

•   Hyphen sequences in page numbers are converted to en-dashes.

•   Month values are converted to standard BibTeX string abbreviations.

•   In titles, sequences of upper-case characters at brace level zero are braced to protect them from being converted to lower-case letters by some bibliography styles.

•   CODEN, ISBN (International Standard Book Number) and ISSN (International Standard Serial Number) entry values are examined to verify the checksums of each listed number, and correct ISBN hyphenation is automatically supplied.

The standardized format of the output of bibclean facilitates the later application of simple filters, such as bibcheck(1), bibdup(1), bibextract(1), bibindex(1), bibjoin(1), biblabel(1), biblook(1), biborder(1), bibsort(1), citefind(1), and citetags(1), to process the text, and also is the one expected by the GNU Emacs BibTeX support functions.

OPTIONS
Command-line switches may be abbreviated to a unique leading prefix, and letter case is not significant. All options are parsed before any input bibliography files are read, no matter what their order on the command line. Options that correspond to a yes/no setting of a flag have a form with a prefix "no-" to set the flag to no. For such options, the last setting determines the flag value used. That is significant when options are also specified in initialization files (see the INITIALIZATION FILES manual section).

The leading hyphen that distinguishes an option from a filename may be doubled, for compatibility with GNU and POSIX conventions. Thus, -author and --author are equivalent.

To avoid confusion with options, if a filename begins with a hyphen, it must be disguised by a leading absolute or relative directory path, e.g., /tmp/-foo.bib or ./-foo.bib.

-author
    Display an author credit on the standard error unit, stderr, and then terminate with a success return code. Sometimes an executable program is separated from its documentation and source code; this option provides a way to recover from that.

-copyleft
    Display copyright information on the standard error unit, stderr, and then terminate with a success return code.

-copyright
    Display copyright information on the standard error unit, stderr, and then terminate with a success return code.

-error-log filename
    Redirect stderr to the indicated file, which then contains all of the error and warning messages. This option is provided for those systems that have difficulty redirecting stderr.

-help or -?
    Display a help message on stderr, giving a usage description, similar to this section of the manual pages, and then terminate with a success return code.

-ISBN-file filename
    Provide an explicit ISBN-range initialization file. It is processed after any system-wide and job-wide ISBN initialization files found on the PATH (for VAX VMS, SYS$SYSTEM) and BIBINPUTS search paths, respectively, and may override them. The ISBN initialization file name can be changed at compile time, or at run time through a setting of the environment variable BIBCLEANISBN, but defaults to .bibclean.isbn on UNIX, and bibclean.isb elsewhere. For further details, see the ISBN INITIALIZATION FILES manual section.

-init-file filename
    Provide an explicit value pattern initialization file. It is processed after any system-wide and job-wide initialization files found on the PATH (for VAX VMS, SYS$SYSTEM) and BIBINPUTS search paths, respectively, and may override them. It in turn may be overridden by a subsequent file-specific initialization file. The initialization file name can be changed at compile time, or at run time through a setting of the environment variable BIBCLEANINI, but defaults to .bibcleanrc on UNIX, and to bibclean.ini elsewhere. For further details, see the INITIALIZATION FILES manual section.

-keyword-file filename
    Provide an explicit keyword initialization file. It is processed after any system-wide and job-wide keyword initialization files found on the PATH (for VAX VMS, SYS$SYSTEM) and BIBINPUTS search paths, respectively, and may override them. The keyword initialization file name can be changed at compile time, or at run time through a setting of the environment variable BIBCLEANKEY, but defaults to .bibclean.key on UNIX, and bibclean.key elsewhere. For further details, see the KEYWORD INITIALIZATION FILES manual section.

-max-width nnn
    bibclean normally limits output line widths to 72 characters, and in the interests of consistency, that value should not be changed. Occasionally, special-purpose applications may require different maximum line widths, so this option provides that capability. The number following the option name can be specified in decimal, octal (starting with 0), or hexadecimal (starting with 0x). A zero or negative value is interpreted to mean unlimited, so -max-width 0 can be used to ensure that each field/value pair appears on a single line.

    When -no-prettyprint requests bibclean to act as a lexical analyzer, the default line width is unlimited, unless overridden by this option.

    When bibclean is prettyprinting, line wrapping is done only at a space. Consequently, a long non-blank character sequence may result in the output exceeding the requested line width.

    When bibclean is lexing, line wrapping is done by inserting a backslash-newline pair when the specified maximum is reached, so no line length ever exceeds the maximum.

-[no-]align-equals
    With the positive form, align the equals sign in key/value assignments at the same column, separated by a single space from the value string. Otherwise, the equals sign follows the key, separated by a single space. Default: no.

-[no-]brace-protect
    Protect uppercase and mixedcase words at brace-level zero with braces to prevent downcasing by some BibTeX styles. Default: yes.

-[no-]check-values
    With the positive form, apply heuristic pattern matching to field values in order to detect possible errors (e.g., ``year = "192"'' instead of ``year = "1992"''), and issue warnings when unexpected patterns are found.

    That checking is usually beneficial, but if it produces too many bogus warnings for a particular bibliography file, you can disable it with the negative form of this option. Default: yes.

-[no-]debug-match-failures
    With the positive form, print out a warning when a value pattern fails to match a value string.

    That is helpful in debugging new patterns, but because the output can be voluminous, you should use this option only with small test files, and initialization files that eliminate all patterns apart from the ones that you are testing. Default: no.

-[no-]delete-empty-values
    With the positive form, remove all field/value pairs for which the value is an empty string. That is helpful in cleaning up bibliographies generated from text editor templates. Compare this option with -[no-]remove-OPT-prefixes described below. Default: no.

-[no-]file-position
    With the positive form, give detailed file position information in warning and error messages. Default: no.

-[no-]fix-accents
    With the positive form, normalize TeX accents in annotes, authors, booktitles, editors, notes, remarks, and titles. Default: no.

-[no-]fix-braces
    With the positive form, normalize bracing in annotes, authors, booktitles, editors, notes, remarks, and titles, by removing unnecessary levels of braces. Default: no.

-[no-]fix-degrees
    With the positive form, remove spaces in author/editor fields inside braces after letter-ending periods. That makes reductions from J. J. {Thomson, M. A., F. R. S.}, Frederick {Soddy, B. A. (Oxon.)}, and John A. {Cable, M. A., M. Ed., Dipl. Deutsch (Marburg), A. L. C. M.} to J. J. {Thomson, M.A., F.R.S.}, Frederick {Soddy, B.A. (Oxon.)}, and John A. {Cable, M.A., M.Ed., Dipl.Deutsch (Marburg), A.L.C.M.}, respectively.

    In journals in the humanities and history of science, as well as in some scientific journals until well into the 20th Century, academic, honorary, and professional titles and degrees are commonly attached to personal names. Even though modern publishing practice avoids such decorations, for accuracy, bibliography entries should preferably retain them. Journal typographical practice generally follows the reductions described here.

-[no-]fix-font-changes
    With the positive form, supply an additional brace level around font changes in titles to protect against downcasing by some BibTeX styles. Font changes that already have more than one level of braces are not modified.

    For example, if a title contains the Latin phrase {\em Dictyostelium discoideum} or {\em {D}ictyostelium discoideum}, then downcasing incorrectly converts the phrase to lower-case letters. Most BibTeX users are surprised that bracing the initial letters does not prevent the downcase action. The correct coding is {{\em Dictyostelium discoideum}}. However, there are also legitimate cases where an extra level of bracing wrongly protects from downcasing. Consequently, bibclean normally does not supply an extra level of braces, but if you have a bibliography where the extra braces are routinely missing, you can use this option to supply them.

    If you think that you need this option, it is strongly recommended that you apply bibclean to your bibliography file with and without -fix-font-changes, then compare the two output files to ensure that extra braces are not being supplied in titles where they should not be present. You must decide which of the two output files is the better choice, then repair the incorrect title bracing by hand.

    Because font changes in titles are uncommon, except for cases of the type that this option is designed to correct, it should do more good than harm. Default: no.

-[no-]fix-initials
    With the positive form, insert a space after a period following author initials. Default: yes.

-[no-]fix-math
    With the positive form, improve readability of math mode in titles by inserting spaces around operators, deleting other unnecessary space, and removing braces around single-character subscripts and superscripts. Default: no.

-[no-]fix-names
    With the positive form, reorder author and editor name lists to remove commas at brace level zero, placing first names or initials before last names. Default: yes.

-[no-]German-style
    With the positive form, interpret quote characters ["] inside braced value strings at brace level 1 according to the conventions of the TeX style file german.sty, which overloads quote to simplify input and representation of German umlaut accents, sharp-s (es-zet), ligature separators, invisible hyphens, raised/lowered quotes, French guillemets, and discretionary hyphens. Recognized character combinations are braced to prevent BibTeX from interpreting the quote as a string delimiter.

    Quoted strings receive no special handling from this option, and because German nouns in titles must anyway be protected from the downcasing operation of most BibTeX bibliography styles, German value strings that use the overloaded quote character can always be entered in the form "{...}", without the need to specify this option at all.

    Default: no.

-[no-]keep-linebreaks
    Normally, line breaks inside value strings are collapsed into a single space, so that long value strings can later be broken to provide lines of reasonable length.

    With the positive form, linebreaks are preserved in value strings. If -max-width is set to zero, this preserves the original line breaks. Spacing outside value strings remains under bibclean's control, and is not affected by this option.

    Default: no.

-[no-]keep-parbreaks
    With the positive form, preserve paragraph breaks (either formfeeds, or lines containing only spaces) in value strings. Normally, paragraph breaks are collapsed into a single space. Spacing outside value strings remains under bibclean's control, and is not affected by this option. Default: no.

-[no-]keep-preamble-spaces
    With the positive form, preserve all whitespace in @Preamble{...} entries. Default: no.

-[no-]keep-spaces
    With the positive form, preserve all spaces in value strings. Normally, multiple spaces are collapsed into a single space. This option can be used together with -keep-linebreaks, -keep-parbreaks, and -max-width 0 to preserve the form of value strings while still providing syntax and value checking. Spacing outside value strings remains under bibclean's control, and is not affected by this option. Default: no.

-[no-]keep-string-spaces
    With the positive form, preserve all whitespace in @String{...} entries. Default: no.

-[no-]parbreaks
    With the negative form, a paragraph break (either a formfeed, or a line containing only spaces) is not permitted in value strings, or between field/value pairs. That may be useful to quickly trap runaway strings arising from mismatched delimiters. Default: yes.

-[no-]prettyprint
    Normally, bibclean functions as a prettyprinter. However, with the negative form of this option, it acts as a lexical analyzer instead, producing a stream of lexical tokens. See the LEXICAL ANALYSIS manual section for further details. Default: yes.

-[no-]print-ISBN-table
    With the positive form, print the ISBN-range table on stderr, then terminate with a success return code.

    That action is taken after all command-line options are processed, and before any input files are read (other than those that are values of command-line options).

    The format of the output ISBN-range table is acceptable for input as an ISBN initialization file (see the ISBN INITIALIZATION FILES manual section). Default: no.

-[no-]print-keyword-table
    With the positive form, print the keyword initialization table on stderr, then terminate with a success return code.

    That action is taken after all command-line options are processed, and before any input files are read (other than those that are values of command-line options).

    The format of the output table is acceptable for input as a keyword initialization file (see the KEYWORD INITIALIZATION FILES manual section). Default: no.

-[no-]print-patterns
    With the positive form, print the value patterns read from initialization files as they are added to internal tables. Use this option to check newly-added patterns, or to see what patterns are being used.

    When bibclean is compiled with native pattern-matching code (the default), those patterns are the ones that are used in checking value strings for valid syntax, and all of them are specified in initialization files, rather than hard-coded into the program. For further details, see the INITIALIZATION FILES manual section. Default: no.

-[no-]quiet
    This option is the opposite of -[no-]warning; it exists for user convenience, and for compatibility with other programs that use -q for quiet operation, without warning messages.

-[no-]read-init-files
    With the negative form, suppress loading of system-, user-, and file-specific initialization files. Initializations then come only from those files explicitly given by -init-file filename options. Default: yes.

-[no-]remove-OPT-prefixes
    With the positive form, remove the ``OPT'' prefix from each field name where the corresponding value is not an empty string. The prefix ``OPT'' must be entirely in upper-case to be recognized.

    This option is for bibliographies generated with the help of the GNU Emacs BibTeX editing support, which generates templates with optional fields identified by the ``OPT'' prefix. Although the function M-x bibtex-remove-OPT normally bound to the keystrokes C-c C-o does the job, users often forget, with the result that BibTeX does not recognize the field name, and ignores the value string. Compare this option with -[no-]delete-empty-values described above. Default: no.

-[no-]scribe
    With the positive form, accept input syntax conforming to the Scribe document system. The output is converted to conform to BibTeX syntax. See the SCRIBE BIBLIOGRAPHY FORMAT manual section for further details. Default: no.

-[no-]trace-file-opening
    With the positive form, record in the error log file the names of all files that bibclean attempts to open. Use this option to identify where initialization files are located. Default: no.

-[no-]warnings
    With the positive form, allow all warning messages. The negative form is not recommended because it may mask problems that should be repaired. Default: yes.

-output-file filename
    Supply an alternate output file to replace stdout. If the filename cannot be opened for output, execution terminates immediately with a nonzero exit code.

-version
    Display the program version number on stderr, and then terminate with a success return code. That includes an indication of who compiled the program, the host name on which it was compiled, the time of compilation, and the type of string-value matching code selected, when that information is available to the compiler.

ERROR RECOVERY AND WARNINGS
When bibclean detects an error, it issues an error message to both stderr and stdout. That way, the user is clearly notified, and the output bibliography also contains the message at the point of error.

Error messages begin with a distinctive pair of queries, ??, beginning in column 1, followed by the input file name and line number. If the -file-position option was specified, they also contain the input and output positions of the current file, entry, and value. Each position includes the file byte number, the line number, and the column number. In the event of a runaway string argument, the entry and value positions should precisely pinpoint the erroneous bibliography entry, and the file positions indicate where it was detected, which may be rather later in the files.

Warning messages identify possible problems, and are therefore sent only to stderr, and not to stdout, so they never appear in the output file. They are identified by a distinctive pair of percents, %%, beginning in column 1, and as with error messages, may be followed by file position messages if the -file-position option was specified.

For convenience, the first line of each error and warning message sent to stderr is formatted according to the expectations of the GNU Emacs next-error command. You can invoke bibclean with the Emacs M-x compile<RET>bibclean filename.bib >filename.new command, then use the next-error command, normally bound to C-x ` (that's a grave, or back, accent), to move to the location of the error in the input file.

If error messages are ignored, and left in the output bibliography file, they precipitates an error when the bibliography is next processed with BibTeX.

After issuing an error message, bibclean then resynchronizes its input by copying it verbatim to stdout until a new bibliography entry is recognized on a line in which the first non-blank character is an at-sign (@). That ensures that nothing is lost from the input file(s), allowing corrections to be made in either the input or the output files. However, if bibclean detects an internal error in its data structures, it terminates abruptly without further input or output processing; that kind of error should never happen, and if it does, it should be reported immediately to the author of the program. Errors in initialization files, and running out of dynamic memory, also immediately terminate bibclean.

SEARCH PATHS
Versions of bibclean before 3.00 found some of their initialization files in the same directory as the executable program. That design choice means that those files can be copied anywhere in the file system, and still be found at run time. Some software distributions, however, prefer to follow the model where initialization and other related files are instead stored in a directory whose name is related to that of the executable by a conventional difference in filepath. For example, a program might be installed in /opt/bin and its associated files in /opt/share/lib/PROGRAMNAME/ or /opt/share/lib/PROGRAMNAME/PROGRAMVERSION/. The second form is preferable, because it permits multiple versions of the same program to be installed, as long as the executable program names carry a version suffix. Thus, a site might have installed programs named bibclean-1.00, bibclean-2.00, bibclean-2.15, and bibclean-3.00, with the versionless name bibclean being a symbolic link to whichever version is the desired local default.

With most software packages, the absolute path to the directory containing associated files is compiled into the program, making it impossible to change the installation locations after the program has been built from source code.

Some packages, however, instead use the location of the executable program to find files by relative path at runtime. In the above example, the program would determine its filesystem location at runtime, say /opt/bin, then find its associated files relative to that location in ../share/lib/PROGRAMNAME/PROGRAMVERSION/.

From version 3.00, bibclean uses that second approach, with an associated directory like ../share/lib/bibclean/3.00. That allows an installation directory tree to be distributed to other systems and unbundled anywhere in the file system, as long as the relative paths are not changed. bibclean tests whether its compiled-in library path is a directory on the local system, and if so, uses it. Otherwise, it replaces that path by a reconstructed one based on the location of the executable program. If the reconstructed path for the library directory does not exist, it uses a warning. In either case, it continues normally.

With the old approach, initialization files on Unix systems were named with a leading period, making them `hidden' files for the ls command. With the new practice, initialization files are no longer named as hidden files.

INITIALIZATION FILES
bibclean can be compiled with one of three different types of pattern matching; the choice is made by the installer at compile time:

    •   The original version uses explicit hand-coded tests of value-string syntax.

    •   The second version uses regular-expression pattern-matching host library routines together with regular-expression patterns that come entirely from initialization files.

    •   The third version uses special patterns that come entirely from initialization files.

The second and third versions are the ones of most interest here, because they allow the user to control what values are considered acceptable. However, command-line options can also be specified in initialization files, no matter which pattern matching choice was selected.

When bibclean starts, it searches for initialization files, finding the first one in the system executable program search path (on UNIX and IBM PC DOS, PATH) and the first one in the BIBINPUTS search path, and processes them in turn. Then, when command-line arguments are processed, any additional files specified by -init-file filename options are also processed. Finally, immediately before each named bibliography file is processed, an attempt is made to process an initialization file with the same name, but with the extension changed to .ini. The default extension can be changed by a setting of the environment variable BIBCLEANEXT. That scheme permits system-wide, user-wide, session-wide, and file-specific initialization files to be supported.

When input is taken from stdin, there is no file-specific initialization.

For precise control, the -no-read-init-files option suppresses all initialization files except those explicitly named by -init-file filename options, either on the command line, or in requested initialization files.

Recursive execution of initialization files with nested -init-file options is permitted; if the recursion is circular, bibclean finally gets a non-fatal initialization file open failure after opening too many files. That terminates further initialization file processing. As the recursion unwinds, the files are all closed, then execution proceeds normally.

An initialization file may contain empty lines, comments from percent to end of line (just like TeX), option switches, and field/pattern or field/pattern/message assignments. Leading and trailing spaces are ignored. That is best illustrated by a short example:

% This is a small bibclean initialization file

-init-file /u/math/bib/.bibcleanrc  %% departmental patterns

chapter = "\"D\""                 %% 23

pages   = "\"D--D\""              %% 23--27

volume  = "\"D \\an\\d D\""       %% 11 and 12

year    = \
   "\"dddd, dddd, dddd\"" \
   "Multiple years specified."      %% 1989, 1990, 1991

-no-fix-names   %% do not modify author/editor lists

Long logical lines can be split into multiple physical lines by breaking at a backslash-newline pair; the backslash-newline pair is discarded. That processing happens while characters are being read, before any further interpretation of the input stream.

Each logical line must contain a complete option (and its value, if any), or a complete field/pattern pair, or a field/pattern/message triple.

Comments are stripped during the parsing of the field, pattern, and message values. The comment start symbol is not recognized inside quoted strings, so it can be freely used in such strings.

Comments on logical lines that were input as multiple physical lines via the backslash-newline convention must appear on the last physical line; otherwise, the remaining physical lines become part of the comment.

Pattern strings must be enclosed in quotation marks; within such strings, a backslash starts an escape mechanism that is commonly used in UNIX software. The recognized escape sequences are:

    \a  alarm bell (octal 007)

    \b  backspace (octal 010)

    \f  formfeed (octal 014)

    \n  newline (octal 012)

    \r  carriage return (octal 015)

    \t  horizontal tab (octal 011)

    \v  vertical tab (octal 013)

    \ooo
        character number octal ooo (e.g \012 is linefeed). Up to 3 octal digits may be used.

    \0xhh
        character number hexadecimal hh (e.g., \0x0a is linefeed). xhh may be in either letter case. Any number of hexadecimal digits may be used.

Backslash followed by any other character produces just that character. Thus, \% gets a literal percent into a string (preventing its interpretation as a comment), \" produces a quotation mark, and \\ produces a single backslash.

An ASCII NUL (\0) in a string terminates it; that is a feature of the C programming language in which bibclean is implemented.

Field/pattern pairs can be separated by arbitrary space, and optionally, either an equals sign or colon functioning as an assignment operator. Thus, the following are equivalent:

pages="\"D--D\""
pages:"\"D--D\""
pages "\"D--D\""
  pages = "\"D--D\""
  pages : "\"D--D\""
pages   "\"D--D\""

Each field name can have an arbitrary number of patterns associated with it; however, they must be specified in separate field/pattern assignments.

An empty pattern string causes previously-loaded patterns for that field name to be forgotten. That feature permits an initialization file to completely discard patterns from earlier initialization files.

Patterns for value strings are represented in a tiny special-purpose language that is both convenient and suitable for bibliography value-string syntax checking. While not as powerful as the language of regular-expression patterns, its parsing can be portably implemented in less than 3% of the code in a widely-used regular-expression parser (the GNU regexp package).

The patterns are represented by the following special characters:

    <space>
        one or more spaces

    a   exactly one letter

    A   one or more letters

    d   exactly one digit

    D   one or more digits

    r   exactly one Roman numeral

    R   one or more Roman numerals (i.e. a Roman number)

    w   exactly one word (one or more letters and digits)

    W   one or more space-separated words, beginning and ending with a word

    .   one `special' character, one of the characters <space>!#()*+,-./:;?[]~, a subset of punctuation characters that are typically used in string values

    :   one or more `special' characters

    X   one or more `special'-separated words, beginning and ending with a word

    \x  exactly one x (x is any character), possibly with an escape sequence interpretation given earlier

    x   exactly the character x (x is anything but one of these pattern characters: aAdDrRwW.:<space>\)

The X pattern character is very powerful, but generally inadvisable, because it matches almost anything likely to be found in a BibTeX value string. The reason for providing pattern matching on the value strings is to uncover possible errors, not mask them.

There is no provision for specifying ranges or repetitions of characters, but that can usually be done with separate patterns. It is a good idea to accompany the pattern with a comment showing the kind of thing it is expected to match. Here is a portion of an initialization file giving a few of the patterns used to match number value strings:

number  =       "\"D\""         %% 23
number  =       "\"A AD\""      %% PN LPS5001
number  =       "\"A D(D)\""    %% RJ 34(49)
number  =       "\"A D\""       %% XNSS 288811
number  =       "\"A D\\.D\""   %% Version 3.20
number  =       "\"A-A-D-D\""   %% UMIAC-TR-89-11
number  =       "\"A-A-D\""     %% CS-TR-2189
number  =       "\"A-A-D\\.D\"" %% CS-TR-21.7

For a bibliography that contains only article entries, that list should probably be reduced to just the first pattern, so that anything other than a digit string fails the pattern-match test. That is easily done by keeping bibliography-specific patterns in a corresponding file with extension .ini, because that file is read automatically.

You should be sure to use empty pattern strings in the pattern file to discard patterns from earlier initialization files.

The value strings passed to the pattern matcher contain surrounding quotes, so the patterns should also. However, you could use a pattern specification like "\"D" to match an initial digit string followed by anything else; the omission of the final quotation mark \" in the pattern allows the match to succeed without checking that the next character in the value string is a quotation mark.

Because the value strings are intended to be processed by TeX, the pattern matching ignores braces, and TeX control sequences, together with any space following those control sequences. Spaces around braces are preserved. That convention allows the pattern fragment A-AD-D to match the value string TN-K\slash 27-70, because the value is implicitly collapsed to TN-K27-70 during the matching operation.

bibclean's normal action when a string value fails to match any of the corresponding patterns is to issue a warning message something like this: "Unexpected value in ``year = "192"''. In most cases, that is sufficient to alert the user to a problem. In some cases, however, it may be desirable to associate a different message with a particular pattern. That can be done by supplying a message string following the pattern string. Format items %% (single percent), %e (entry name), %f (field name), %k (citation key), and %v (string value) are available to get current values expanded in the messages. Here is an example:

chapter = "\"D:D\"" "Colon found in ``%f = %v''" %% 23:2

To be consistent with other messages output by bibclean, the message string should not end with punctuation.

If you wish to make the message an error, rather than just a warning, begin it with a query (?), like this:

chapter = "\"D:D\"" "?Colon found in ``%f = %v''" %% 23:2

The query is be included in the output message.

Escape sequences are supported in message strings, just as they are in pattern strings. You can use that to advantage for fancy things, such as terminal display mode control. If you rewrite the previous example as

chapter = "\"D:D\"" \
          "?\033[7mColon found in ``%f = %v''\033[0m" %% 23:2

the error message appears in inverse video on display screens that support ANSI terminal control sequences. Such practice is not normally recommended, because it may have undesirable effects on some output devices. Nevertheless, you may find it useful for restricted applications.

For some types of bibliography fields, bibclean contains special-purpose code to supplement or replace the pattern matching:

    •   CODEN, ISBN and ISSN field values are handled that way because their validation requires evaluation of checksums that cannot be expressed by simple patterns; no patterns are even used in these three cases.

    •   When bibclean is compiled with pattern-matching code support, chapter, number, pages, and volume values are checked only by pattern matching.

    •   month values are first checked against the standard BibTeX month abbreviations, and only if no match is found are patterns then used.

    •   year values are first checked against patterns, then if no match is found, the year numbers are found and converted to integer values for testing against reasonable bounds.

Values for other fields are checked only against patterns. You can provide patterns for any field you like, even ones bibclean does not already know about. New ones are simply added to an internal table that is searched for each string to be validated.

The special field, key, represents the bibliographic citation key. It can be given patterns, like any other field. Here is an initialization file pattern assignment that matches an author name, a colon, a four-digit year, a colon, and an alphabetic string, in the BibNet Project style:

key = "A:dddd:A"                     %% Knuth:1986:TB

Notice that no quotation marks are included in the pattern, because the citation keys are not quoted. You can use such patterns to help enforce uniform naming conventions for citation keys, which is increasingly important as your bibliography data base grows.

ISBN INITIALIZATION FILES
bibclean contains a compiled-in table of ISBN ranges and country/language settings that is suitable for most applications.

However, ISBN data change yearly, as new countries adopt ISBNs, and as publishers are granted new, or additional, ISBN prefixes.

Thus, from version 2.12, bibclean supports reading of run-time ISBN initialization files found on the PATH (for VAX VMS, SYS$SYSTEM) and BIBINPUTS search paths, and then any specified by -ISBN-file filename options.

That feature makes it possible to incorporate new ISBN data without having to produce a new bibclean release and reinstall the software at end-user sites.

The format of an ISBN initialization file is similar to that of the bibclean initialization files described in the preceding section: comments begin with percent and continue to end of line, blank and empty lines are ignored, backslash-newline joins adjacent lines, and otherwise, lines are expected to contain a required pair of ISBN country/language-publisher prefixes forming a non-decreasing range, optionally followed by one or more words of text that are treated as the country/language group value. The latter value plays no part in ISBN validation, but its presence is strongly recommended, in order to make the ISBN table more understandable for humans.

Here is a short example:
    %% The Faeroes got ISBN assignments between 1993 and 1998
    99918-0         99918-3        Faeroes
    99918-40        99918-61
    99918-900       99918-938
It is not necessary to repeat the country names on succeeding entries with the same initial number (99918 in that example); that is handled internally.

Data from ISBN files normally augment the compiled-in data. However, if the first prefix begins with a hyphen, then bibclean deletes the first entry in the table matching that first prefix (ignoring the leading hyphen):
    %% Latvia got ISBN ranges between 1993 and 1998
    %% so we remove the old placeholder, then add the
    %% new ranges.
    -9984-0         9984-9         This one is no longer valid

    9984-00         9984-20        Latvia
    9984-500        9984-770
    9984-9000       9984-9984

KEYWORD INITIALIZATION FILES
bibclean contains a compiled-in table of keyword mappings that is suitable for most applications. The default settings merely adjust lettercase in certain keyword names, so that, for example, isbn is output as ISBN.

From version 2.12, bibclean supports reading of run-time keyword initialization files found on the PATH (for VAX VMS, SYS$SYSTEM) and BIBINPUTS search paths, and then any specified by -keyword-file filename options.

That feature makes it possible to incorporate special spellings of new keywords without having to produce a new bibclean release and reinstall the software at end-user sites.

The format of a keyword initialization file is similar to that of the other bibclean initialization files described in the preceding sections: comments begin with percent and continue to end of line, blank and empty lines are ignored, backslash-newline joins adjacent lines, and otherwise, lines are expected to contain a required pair of old and new keyword names.

Here is a short example:
    %% We want special handling of MathReviews keywords
    mrclass         MRclass
    mrnumber        MRnumber
    mrreviewer      MRreviewer

Data from keywords files normally augment the compiled-in data. However, if the first keyword begins with a hyphen, then bibclean deletes the first entry in the table matching that keyword (ignoring the leading hyphen):
    %% Remove special handling of ISBN, ISSN, and LCCN values.
    -issn           ISSN
    -isbn           ISBN
    -lccn           LCCN
Even though the second keyword in each deletion pair is not used, it still must be specified.

Notice that this feature can be used to regularize keyword names, but use it with care, in order to avoid producing duplicate key names in output BibTeX entries:
    %% Map variations of keywords into a common name:
    keys            keywords
    keywds          keywords
    keyword         keywords
    keywrd          keywords
    keywrds         keywords
    searchkey       keywords

LEXICAL ANALYSIS
When -no-prettyprint is specified, bibclean acts as a lexical analyzer instead of a prettyprinter, producing output in lines of the form

    <token-number><tab><token-name><tab>"<token-value>"

Each output line contains a single complete token, identified by a small integer number for use by a computer program, a token type name for human readers, and a string value in quotes.

Special characters in the token value string are represented with ANSI/ISO Standard C escape sequences, so all characters other than NUL are representable, and multi-line values can be represented in a single line.

Here are the token numbers and token type names that can appear in the output when -prettyprint is specified:

     0   UNKNOWN
     1   ABBREV
     2   AT
     3   COMMA
     4   COMMENT
     5   ENTRY
     6   EQUALS
     7   FIELD
     8   INCLUDE
     9   INLINE
    10   KEY
    11   LBRACE
    12   LITERAL
    13   NEWLINE
    14   PREAMBLE
    15   RBRACE
    16   SHARP
    17   SPACE
    18   STRING
    19   VALUE

Programs that parse such output should also be prepared for lines beginning with the warning prefix, %%, or the error prefix, ??, and for ANSI/ISO Standard C line-number directives of the form
    # line 273 "texbook1.bib"
that record the line number and file name of the current input file.

If a -max-width nnn command-line option was specified, long output lines are wrapped at a backslash-newline pair, and consequently, software that processes the lexical token stream should be prepared to collapse such wrapped lines back into single lines.

As an example of the use of -no-prettyprint, the UNIX command pipeline
    bibclean -no-prettyprint mylib.bib | \
        awk '$2 == "KEY" {print $3}' | \
        sed -e 's/"//g' | \
        sort
extracts a sorted list of all citation keys in the file mylib.bib.

A certain amount of processing has been done on the tokens. In particular, delimiters equivalent to braces have been replaced by braces, and braced strings have become quoted strings.

The LITERAL token type is used for arbitrary text that bibclean does not examine further, such as the contents of a @Preamble{...} or a @Comment{...}.

The UNKNOWN token type should never appear in the output stream. It is used internally to initialize token type variables.

SCRIBE BIBLIOGRAPHY FORMAT
bibclean's support for the Scribe bibliography format is based on the syntax description in the Scribe Introductory User's Manual, 3rd Edition, May 1980. Scribe was originally developed by Brian Reid at Carnegie-Mellon University, and was marketed by Unilogic, Ltd., later renamed to Scribe Systems, and apparently now long defunct.

The BibTeX bibliography format was strongly influenced by Scribe, and indeed, with care, it is possible to share bibliography files between the two systems. Nevertheless, there are some differences, so here is a summary of features of the Scribe bibliography file format:

(1) Letter case is not significant in field names and entry names, but case is preserved in value strings.

(2) In field/value pairs, the field and value may be separated by one of three characters: =, /, or space. Space may optionally surround these separators.

(3) Value delimiters are any of these seven pairs: { } [ ] ( ) < > ' ' " " ` `

(4) Value delimiters may not be nested, even though with the first four delimiter pairs, nested balanced delimiters would be unambiguous.

(5) Delimiters can be omitted around values that contain only letters, digits, sharp (#), ampersand (&), period (.), and percent (%).

(6) Outside of delimited values, a literal at-sign (@) is represented by doubled at-signs (@@).

(7) Bibliography entries begin with @name, as for BibTeX, but any of the seven Scribe value delimiter pairs may be used to surround the values in field/value pairs. As in (4), nested delimiters are forbidden.

(8) Arbitrary space may separate entry names from the following delimiters.

(9) @Comment is a special command whose delimited value is discarded. As in (4), nested delimiters are forbidden.

(10)
    The special form

    @Begin{comment}
     ...
    @End{comment}

    permits encapsulating arbitrary text containing any characters or delimiters, other than ``@End{comment}''. Any of the seven delimiter pairs may be used around the word ``comment'' following the ``@Begin'' or ``@End''; the delimiters in the two cases need not be the same, and consequently, ``@Begin{comment}''/``@End{comment}'' pairs may not be nested.

(11)
    The key field is required in each bibliography entry.

(12)
    A backslashed quote in a string is assumed to be a TeX accent, and braced appropriately. While such accents do not conform to Scribe syntax, Scribe-format bibliographies have been found that appear to be intended for TeX processing.

Because of that loose syntax, bibclean's normal error detection heuristics are less effective, and consequently, Scribe mode input is not the default; it must be explicitly requested.

ENVIRONMENT VARIABLES

BIBCLEANEXT
    File extension of bibliography-specific initialization files. Default: .ini.

BIBCLEANINI
    Name of bibclean initialization files. Default: .bibcleanrc (UNIX), bibclean.ini (non-UNIX).

BIBCLEANISBN
    Name of bibclean ISBN initialization files. Default: .bibclean.isbn (UNIX), bibclean.isb (non-UNIX).

BIBCLEANKEY
    Name of bibclean keyword initialization files. Default: .bibclean.key (UNIX), bibclean.key (non-UNIX).

BIBINPUTS
    Search path for bibclean and BibTeX input files. On UNIX, it is a colon-separated list of directories that are searched in order from first to last. It is not an error for a specified directory to not exist.

    On other operating systems, the directory names should be separated by whatever character is used in system search path specifications, such as a semicolon on IBM PC DOS.

PATH
    On Atari TOS, IBM PC DOS, IBM PC OS/2, Microsoft NT, and UNIX, search path for system executable files. The system-wide bibclean initialization file is searched for in that path.

SYS$SYSTEM
    On VAX VMS, search path for system executable files and the system-wide bibclean initialization file.

FILES

*.bib
    BibTeX and Scribe bibliography data base files.

*.ini
    File-specific initialization files.

.bibclean.isbn
    UNIX system-wide and user-specific ISBN initialization files.

.bibclean.key
    UNIX system-wide and user-specific keyword initialization files.

.bibcleanrc
    UNIX system-wide and user-specific initialization files.

bibclean.ini
    Non-UNIX system-wide and user-specific initialization files.

bibclean.isb
    Non-UNIX system-wide and user-specific ISBN initialization files.

bibclean.key
    Non-UNIX system-wide and user-specific keyword initialization files.

SEE ALSO
bibcheck(1), bibdup(1), bibextract(1), bibindex(1), bibjoin(1), biblabel(1), biblex(1), biblook(1), biborder(1), bibparse(1), bibsearch(1), bibsort(1), bibtex(1), bibunlex(1), citefind(1), citesub(1), citetags(1), latex(1), scribe(1), tex(1).

AUTHOR
Nelson H. F. Beebe
University of Utah
Department of Mathematics, 110 LCB
155 S 1400 E RM 233
Salt Lake City, UT 84112-0090
USA
Tel: +1 801 581 5254
FAX: +1 801 581 4148
Email: beebe@math.utah.edu, beebe@acm.org, beebe@computer.org (Internet)
URL: http://www.math.utah.edu/~beebe

COPYRIGHT
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###                                                                  ###
###     bibclean: prettyprint and syntax check BibTeX and Scribe     ###
###                   bibliography data base files                   ###
###                                                                  ###
###           Copyright (C) 1990--2016 Nelson H. F. Beebe            ###
###                                                                  ###
### This program is covered by the GNU General Public License (GPL), ###
### version 2 or later, available as the file COPYING in the program ###
### source distribution, and on the Internet at                      ###
###                                                                  ###
###               ftp://ftp.gnu.org/gnu/GPL                          ###
###                                                                  ###
###               http://www.gnu.org/copyleft/gpl.html               ###
###                                                                  ###
### This program is free software; you can redistribute it and/or    ###
### modify it under the terms of the GNU General Public License as   ###
### published by the Free Software Foundation; either version 2 of   ###
### the License, or (at your option) any later version.              ###
###                                                                  ###
### This program is distributed in the hope that it will be useful,  ###
### but WITHOUT ANY WARRANTY; without even the implied warranty of   ###
### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    ###
### GNU General Public License for more details.                     ###
###                                                                  ###
### You should have received a copy of the GNU General Public        ###
### License along with this program; if not, write to the Free       ###
### Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,   ###
### MA 02111-1307 USA                                                ###
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