Blank lines

Blank lines, or lines consisting entirely of whitespace, are ignored.

Comments

Comments start with the # character and continue up to and including the end of the line. While leading whitespace is permitted, comments are treated as such only if they are on lines by themselves.

Variable definitions

Variable definition lines are of the form:

variable_name argument(s)

where variable_name is a member of one of the types described in the remaining sections, and argument(s) are specific to every variable name. For variable_name, case is irrelevant.

Boolean variables

Variables of this type take one argument that must be one of: f, false, n, no, off, on, t, true, y, or yes. Case is irrelevant. Variables of this type are: AssociateMeta, ExtractFilter, FollowLinks, Incremental, LaunchdCooperation, RecurseSubdirs, SearchBackground, StemWords, and StoreWordPositions.

Enumeration variables

Variables of this type are just like string variables (see below) except that the argument must be one of a set of pre-determined values. Case is irrelevant. Variables of this type are: ResultsFormat and SearchDaemon. ResultsFormat must be either: classic or XML. SearchDaemon must be one of: none, tcp, unix, or both.

Filter variables

Variables of this type are of the form:

pattern command

where pattern is a shell pattern (regular expression) and command is the command-line to execute the filter.

Within a command, there are a few % substitutions that are done at run-time:

That is: the % and one character immediately after it are substituted as described in the above table. Substituted filenames are skipped past and not rescanned for more substitutions, but the remainder of the command is. To use a literal % or @, simply double it. (For more on filter variables, see FILTERS below.)

Variables of this type are: FilterAttachment and FilterFile.

Integer variables

Variables of this type take one numeric argument. A special string of infinity is taken to mean ``the largest possible integer value.'' Case is irrelevant. Variables of this type are: FilesReserve, ResultsMax, SocketQueueSize, SocketTimeout, ThreadsMax, ThreadsMin, ThreadTimeout, TitleLines, Verbosity, WordFilesMax, WordPercentMax, WordsNear, and WordThreshold.

For WordThreshold, only the super-user can specify a value larger than the compiled-in default.

Percentage variables

Variables of this type are like integer variables except that if an optional trailing percent sign (%) is present, the value is taken to be a percentage rather than an absolute number. Variables of this type are: FilesGrow.

String variables

Variables of this type take one argument that is the remainder of the line minus leading and trailing whitespace. To preserve whitespace, surround the argument in either single or double quotes. The quotes themselves are stripped from the argument, but only if they match. Variables of this type are: ExtractExtension, Group, IndexFile, PidFile, ResultSeparator, SocketFile, StopWordFile, TempDirectory, and User.

Set variables

Variables of this type take one or more arguments separated by whitespace. Variables of this type are: ExcludeClass, ExcludeFile, ExtractFile, and ExcludeMeta.

Other variables

Variables of this type are: IncludeFile, IncludeMeta, and SocketAddress.

An IncludeFile configuration file line is of the form:

module_name pattern ...

where module_name is the name of the module (case is irrelevant) to handle the indexing of the filename patterns that follow. Module names are: text (plain text), HTML (HTML and XHTML), ID3 (ID3 tags), LaTeX (LaTeX source), Mail (mail and news messages), Man (Unix manual pages), and RTF (Rich Text Format).

An IncludeMeta configuration file line is of the form:

name[=new_name] ...

It is like a set variable except arguments may optionally be followed by reassignments. For example, a value of:

adr=address

says to include and index the words associated with the meta name adr, but to store the name as address in the generated index file so that queries would use address rather than adr.

A SocketAddress configuration file line is of the form:

[ host : ] port

that is: an optional host and colon followed by a port number. The host may be one of a host name, an IPv4 address (in dot-decimal notation), an IPv6 address (in colon notation) if supported by the operating system, or the * character meaning ``any IP address.'' Omitting the host and colon also means ``any IP address.''

Filtering files

Via the FilterFile configuration file variable, files matching patterns can be filtered prior to indexing or extraction. For example, to uncompress bzip2'd, gzip'd, and compress'd files prior to indexing or extraction, the FilterFile variable lines in a configuration file would be:

FilterFile *.bz2  bunzip2 -c %f > @%F
FilterFile *.gz   gunzip -c %f > @%F
FilterFile *.Z    uncompress -c %f > @%F

Given that, a filename such as foo.txt.gz would become foo.txt. If files having txt extensions should be indexed, then it will be. Note that the command on the FilterFile line must not simply be:

gunzip @%f				# WRONG!

because gunzip will replace the compressed file with the uncompressed one.

Here's an example to convert PDF to plain text for indexing using the xpdf(1) package's pdftotext command:

FilterFile *.pdf  pdftotext %f @%F.txt

A file can be filtered more than once prior to indexing or extraction, i.e., filters can be ``chained'' together. For example, if the uncompression and PDF examples shown above are used together, compressed PDF files will also be indexed or extracted, i.e., filenames ending with one of .pdf.bz2, .pdf.gz, or .pdf.Z double extensions.

Note, however, that just because a filename has an extension for which a filter has been specified does not mean that a file will be filtered and subsequently indexed or extracted. When index++ or extract++ encounters a file having an extension for which a filter has been specified, it performs the filename substitution(s) on it first to determine what the target filename would be. If the extension of that filename should be indexed or extracted (because it is among the set of extensions specified with either the -e or --pattern options or the IncludeFile variable or is not among the set specified with either the -E or --no-pattern options or the ExcludeFile variable), then the filter(s) are executed to create it.

Filtering attachments

Via the FilterAttachment configuration file variable, e-mail attachments whose MIME types match particular patterns can be filtered and thus indexed. An attachment is written to a temporary file by itself (after having been base-64 decoded, if necessary) and a filter command is called on that file.

For example, to convert a PDF attachment to plain text so it can be indexed, the FilterAttachment variable line in a configuration file would be:

FilterAttachment application/pdf    pdftotext %f @%F.txt

MIME types must be specified entirely in lower case. Patterns can be useful for MIME types. For example:

FilterAttachment application/*word  extract++ -f %f > @%F.txt

can be used regardless of whether the MIME type is application/msword (the official MIME type for Microsoft Word documents) or application/vnd.ms-word (an older version).

The MIME types that are built into index++(1) are: text/plain, text/enriched (but only if the RTF module is compiled in), text/html (but only if the HTML module is compiled in), text/*vcard, message/rfc822, multipart/something (where something is one of: alternative, mixed, or parallel). FilterAttachment variable lines can override the handling of the built-in MIME types.

Unlike file filters, attachment filters must convert directly to plain text and can not be ``chained'' together. (This restriction exists because there is no way to know what any intermediate MIME types would be to apply more filters.)